# EDGAR Filing Document

**Accession Number:** 0000822632
**File Stem:** 0001193125-26-076075
**Filing Date:** 2026-2
**Character Count:** 1012702
**Document Hash:** 0399ee24b76b88e6355069670ac37a09
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-076075.hdr.sgml**: 20260226

**ACCESSION NUMBER**: 0001193125-26-076075

**CONFORMED SUBMISSION TYPE**: N-CSR

**PUBLIC DOCUMENT COUNT**: 148

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260226

**DATE AS OF CHANGE**: 20260226

**EFFECTIVENESS DATE**: 20260226

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** WILLIAM BLAIR FUNDS
- **CENTRAL INDEX KEY:** 0000822632

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** N-CSR
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-05344
- **FILM NUMBER:** 26686767

**BUSINESS ADDRESS:**
- **STREET 1:** 150 NORTH RIVERSIDE PLAZA
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606
- **BUSINESS PHONE:** 3123648000

**MAIL ADDRESS:**
- **STREET 1:** 150 NORTH RIVERSIDE PLAZA
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** WILLIAM BLAIR MUTUAL FUNDS INC
- **DATE OF NAME CHANGE:** 19960112

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BLAIR WILLIAM READY RESERVES INC
- **DATE OF NAME CHANGE:** 19920316

## Series and Classes Contracts Data

### William Blair Growth Fund (Series ID: S000008594)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023523 | Class N      | WBGSX           |
| C000023524 | Class I      | BGFIX           |
| C000211716 | Class R6     | BGFRX           |

### William Blair International Small Cap Growth Fund (Series ID: S000008595)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023525 | Class N      | WISNX           |
| C000023526 | Class I      | WISIX           |
| C000023527 | Class R6     | WIISX           |

### William Blair Emerging Markets Growth Fund (Series ID: S000008596)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023528 | Class N      | WBENX           |
| C000023529 | Class I      | WBEIX           |
| C000023530 | Class R6     | BIEMX           |

### William Blair Small Cap Value Fund (Series ID: S000008597)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023531 | Class N      | WBVNX           |
| C000023532 | Class I      | ICSCX           |
| C000211717 | Class R6     | WBVRX           |

### William Blair Large Cap Growth Fund (Series ID: S000008601)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023538 | Class N      | LCGNX           |
| C000023539 | Class I      | LCGFX           |
| C000211719 | Class R6     | LCGJX           |

### William Blair Small Cap Growth Fund (Series ID: S000008602)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023540 | Class N      | WBSNX           |
| C000023541 | Class I      | WBSIX           |
| C000211720 | Class R6     | WBSRX           |

### William Blair Small-Mid Cap Growth Fund (Series ID: S000008603)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023542 | Class N      | WSMNX           |
| C000023543 | Class I      | WSMDX           |
| C000211721 | Class R6     | WSMRX           |

### William Blair International Growth Fund (Series ID: S000008604)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000023544 | Class N      | WBIGX           |
| C000023545 | Class I      | BIGIX           |
| C000211722 | Class R6     | WBIRX           |

### William Blair Institutional International Growth Fund (Series ID: S000008605)

| Class ID   | Class Name          | Ticker Symbol   |
|:---|:---|:---|
| C000023546 | Institutional Class | WBIIX           |

### William Blair Global Leaders Fund (Series ID: S000019315)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000053607 | Class N      | WGGNX           |
| C000053608 | Class I      | WGFIX           |
| C000053609 | Class R6     | BGGIX           |

### William Blair Emerging Markets Leaders Fund (Series ID: S000021052)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000059867 | Class I      | WBELX           |
| C000059868 | Class R6     | WELIX           |
| C000088850 | Class N      | WELNX           |

### William Blair Emerging Markets Small Cap Growth Fund (Series ID: S000034349)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000105753 | Class I      | BESIX           |
| C000105754 | Class N      | WESNX           |
| C000105755 | Class R6     | WESJX           |

### William Blair International Leaders Fund (Series ID: S000037763)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000116468 | Class N      | WILNX           |
| C000116469 | Class I      | WILIX           |
| C000116470 | Class R6     | WILJX           |

### William Blair Small-Mid Cap Core Fund (Series ID: S000066499)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000214491 | Class I      | WBCIX           |
| C000214492 | Class R6     | WBCRX           |

### William Blair Emerging Markets Debt Fund (Series ID: S000069167)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000221008 | Class R6     | WEDRX           |
| C000221009 | Class I      | WEDIX           |

### William Blair China Growth Fund (Series ID: S000072753)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000229252 | Class I      | WICGX           |
| C000229253 | Class R6     | WRCGX           |

### William Blair Emerging Markets ex China Growth Fund (Series ID: S000075390)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000234384 | Class I      | WXCIX           |
| C000234385 | Class R6     | WXCRX           |

### William Blair Mid Cap Value Fund (Series ID: S000075391)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000234386 | Class I      | WVMIX           |
| C000234387 | Class R6     | WVMRX           |

### William Blair Small-Mid Cap Value Fund (Series ID: S000080810)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000243363 | Class I      | ISMVX           |
| C000243364 | Class R6     | RSMVX           |

?xml version='1.0' encoding='ASCII'? 22429ffb-9a75-4d87-bf60-56072e94fd1c

#### UNITED STATES

#### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

------

#### FORM N-CSR

------

#### CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES

#### Investment Company Act file number

#### 811-5344

#### William Blair Funds
(Exact name of registrant as specified in charter)

------

150 North Riverside Plaza, Chicago, IL 60606

(Address of Principal Executive Offices) (Zip Code)

#### Registrant's telephone number, including area code:

#### 312-236-1600

#### Date of fiscal year end:

#### December 31

#### Date of reporting period:

#### December 31, 2025
Item 1. Report to Stockholders.

(a) The registrant's annual reports transmitted to shareholders pursuant to Rule 30e-1 under the Investment Company Act of 1940 are as follows:

### William Blair Growth Fund

#### Class I / BGFIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Growth Fund Class I | $96 | 0.91% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 10.57% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 3000<sup>®</sup> Growth Index, which returned 18.15% and underperformed the S&P 500<sup>®</sup> Index, a broad measure of market performance, which returned 17.88%.

The Fund's underperformance versus its benchmark was driven by stock-specific dynamics and style factors. From a style perspective, our typical bias towards small and mid-caps was a headwind. From a stock perspective, selection across multiple sectors including Information Technology and Health Care dampened results. The top individual detractors included ACV Auctions (Industrials), ServiceNow (Information Technology), UnitedHealth Group (Health Care), Chipotle Mexican Grill (Consumer Discretionary), and Copart (Industrials). The top individual contributors for the period included Cameco (Energy), Advanced Micro Devices (Information Technology), Uber Technologies (Industrials), Nvidia (Information Technology), as well as our underweight to Apple (Information Technology).

#### TOP PERFORMANCE CONTRIBUTORS
**Cameco** is focused on the mining, trading, and processing of uranium, a key input into nuclear power generation. The stock outperformed as Cameco delivered strong results for the period, supported by higher sales and realized pricing. With global nuclear capacity expanding and uranium supplies tightening, we believe that the market outlook remains constructive. We believe that the company stands to benefit significantly from this demand surge, underpinned by nuclear energy's essential role in the low-carbon transition.

**Advanced Micro Devices**, a semiconductor company, delivered strong revenue on strength across its portfolio, bolstered by deep engagement across its CPU business as well as a partnership with OpenAI to deliver capacity through its GPUs and rack scale artificial intelligence ("AI") solutions.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. The stock underperformed as the company endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**ServiceNow** is a provider of cloud-based service management and business management solutions. Despite delivering solid operational execution and strong subscription growth, shares lagged during the period as concerns over potential AI disruption hindered the valuations of many software-related companies. However, we feel ServiceNow is well positioned to benefit from AI as they embed AI capabilities into existing workflows and introduce new offerings.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_40836.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Growth Fund Class I** | 10.57% | 10.02% | 14.27% |
| **S&P 500<sup>®</sup> Index** | 17.88% | 14.42% | 14.82% |
| **Russell 3000<sup>®</sup> Growth Index** | 18.15% | 14.59% | 17.59% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$228365 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;51 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1748 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;62% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 11.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 7.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 6.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 4.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 4.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 4.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 4.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Broadcom, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Advanced Micro Devices, Inc. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Walmart, Inc. | 3.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_40820.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Growth Fund

#### Class N / WBGSX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Growth Fund Class N | $126 | 1.20% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 10.19% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 3000<sup>®</sup> Growth Index, which returned 18.15% and underperformed the S&P 500<sup>®</sup> Index, a broad measure of market performance, which returned 17.88%.

The Fund's underperformance versus its benchmark was driven by stock-specific dynamics and style factors. From a style perspective, our typical bias towards small and mid-caps was a headwind. From a stock perspective, selection across multiple sectors including Information Technology and Health Care dampened results. The top individual detractors included ACV Auctions (Industrials), ServiceNow (Information Technology), UnitedHealth Group (Health Care), Chipotle Mexican Grill (Consumer Discretionary), and Copart (Industrials). The top individual contributors for the period included Cameco (Energy), Advanced Micro Devices (Information Technology), Uber Technologies (Industrials), Nvidia (Information Technology), as well as our underweight to Apple (Information Technology).

#### TOP PERFORMANCE CONTRIBUTORS
**Cameco** is focused on the mining, trading, and processing of uranium, a key input into nuclear power generation. The stock outperformed as Cameco delivered strong results for the period, supported by higher sales and realized pricing. With global nuclear capacity expanding and uranium supplies tightening, we believe that the market outlook remains constructive. We believe that the company stands to benefit significantly from this demand surge, underpinned by nuclear energy's essential role in the low-carbon transition.

**Advanced Micro Devices**, a semiconductor company, delivered strong revenue on strength across its portfolio, bolstered by deep engagement across its CPU business as well as a partnership with OpenAI to deliver capacity through its GPUs and rack scale artificial intelligence ("AI") solutions.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. The stock underperformed as the company endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**ServiceNow** is a provider of cloud-based service management and business management solutions. Despite delivering solid operational execution and strong subscription growth, shares lagged during the period as concerns over potential AI disruption hindered the valuations of many software-related companies. However, we feel ServiceNow is well positioned to benefit from AI as they embed AI capabilities into existing workflows and introduce new offerings.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_40804.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Growth Fund Class N** | 10.19% | 9.69% | 13.94% |
| **S&P 500<sup>®</sup> Index** | 17.88% | 14.42% | 14.82% |
| **Russell 3000<sup>®</sup> Growth Index** | 18.15% | 14.59% | 17.59% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$228365 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;51 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1748 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;62% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 11.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 7.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 6.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 4.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 4.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 4.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 4.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Broadcom, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Advanced Micro Devices, Inc. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Walmart, Inc. | 3.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_40773.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Growth Fund

#### Class R6 / BGFRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Growth Fund Class R6 | $92 | 0.87% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 10.66% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 3000<sup>®</sup> Growth Index, which returned 18.15% and underperformed the S&P 500<sup>®</sup> Index, a broad measure of market performance, which returned 17.88%.

The Fund's underperformance versus its benchmark was driven by stock-specific dynamics and style factors. From a style perspective, our typical bias towards small and mid-caps was a headwind. From a stock perspective, selection across multiple sectors including Information Technology and Health Care dampened results. The top individual detractors included ACV Auctions (Industrials), ServiceNow (Information Technology), UnitedHealth Group (Health Care), Chipotle Mexican Grill (Consumer Discretionary), and Copart (Industrials). The top individual contributors for the period included Cameco (Energy), Advanced Micro Devices (Information Technology), Uber Technologies (Industrials), Nvidia (Information Technology), as well as our underweight to Apple (Information Technology).

#### TOP PERFORMANCE CONTRIBUTORS
**Cameco** is focused on the mining, trading, and processing of uranium, a key input into nuclear power generation. The stock outperformed as Cameco delivered strong results for the period, supported by higher sales and realized pricing. With global nuclear capacity expanding and uranium supplies tightening, we believe that the market outlook remains constructive. We believe that the company stands to benefit significantly from this demand surge, underpinned by nuclear energy's essential role in the low-carbon transition.

**Advanced Micro Devices**, a semiconductor company, delivered strong revenue on strength across its portfolio, bolstered by deep engagement across its CPU business as well as a partnership with OpenAI to deliver capacity through its GPUs and rack scale artificial intelligence ("AI") solutions.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. The stock underperformed as the company endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**ServiceNow** is a provider of cloud-based service management and business management solutions. Despite delivering solid operational execution and strong subscription growth, shares lagged during the period as concerns over potential AI disruption hindered the valuations of many software-related companies. However, we feel ServiceNow is well positioned to benefit from AI as they embed AI capabilities into existing workflows and introduce new offerings.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_40875.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **Since Inception** |
| **Growth Fund Class R6** | 10.66% | 10.08% | 14.34% |
| **S&P 500<sup>®</sup> Index** | 17.88% | 14.42% | 15.43% |
| **Russell 3000<sup>®</sup> Growth Index** | 18.15% | 14.59% | 18.39% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$228365 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;51 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1748 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;62% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 11.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 7.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 6.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 4.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 4.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 4.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 4.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Broadcom, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Advanced Micro Devices, Inc. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Walmart, Inc. | 3.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_40846.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Large Cap Growth Fund

#### Class I / LCGFX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Large Cap Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Large Cap Growth Fund Class I | $69 | 0.65% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 11.68% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 1000<sup>®</sup> Growth Index (the "Index"), which returned 18.56% and underperformed the Russell 1000<sup>®</sup> Index, a broad measure of market performance, which returned 17.37%.

The Fund lagged the return of its benchmark in the full year period, driven by stock-specific dynamics and style headwinds. Information Technology, including our positions in ServiceNow, Tyler Technologies and Salesforce, as well as not owning Palantir Technologies, detracted from returns. Other detractors included Chipotle Mexican Grill (Consumer Discretionary) and UnitedHealth Group (Health Care). From a style perspective, and since the market trough on April 8th, stocks with higher fundamental volatility and higher beta significantly outperformed, creating a headwind to relative performance given our focus on companies with more durable growth. The top contributors for the period included IDEXX Laboratories (Health Care), Lam Research (Information Technology), Broadcom (Information Technology), Uber Technologies (Industrials) and Monster Beverage (Consumer Staples). Not owning Home Depot (Consumer Discretionary) and Adobe (Information Technology) were also tailwinds to performance for the period.

#### TOP PERFORMANCE CONTRIBUTORS
**IDEXX Laboratories** is a global leader in pet healthcare diagnostics. The stock outperformed as IDEXX delivered strong top- and bottom-line growth during the period, driven by strong performance from its high-margin Companion Animal Group (CAG), which achieved a record number of premium instrument placements in the quarter. IDEXX continues to introduce new testing categories and advanced technology that we believe sets the standard for the industry.

**Broadcom** designs, develops, and manufactures a wide range of semiconductor and infrastructure software products. Outperformance during the period was supported by strength in artificial intelligence ("AI") related demand, ethernet networking, and software. While AI infrastructure demand remains a core growth driver, Broadcom is also seeing increased inference activity among key customers helping to drive growth.

#### TOP PERFORMANCE DETRACTORS
**ServiceNow** is a provider of cloud-based service management and business management solutions. Despite delivering solid operational execution and strong subscription growth, shares lagged during the period as concerns over potential AI disruption hindered the valuations of many software-related companies. However, we feel ServiceNow is well positioned to benefit from AI as they embed AI capabilities into existing workflows and introduce new offerings.

**Chipotle Mexican Grill** is a fast-casual restaurant chain that operates thousands of company-owned locations across North America and select international markets. Shares lagged during the period as same store sales growth fell short of expectations, driven by a decline in transactions, and a reduction in forward-looking revenue guidance by management. While uncertainty remains with respect to timing around a recovery in traffic, restaurant level margins remain healthy, with continued operational efficiencies ahead.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_40948.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Large Cap Growth Fund Class I** | 11.68% | 11.40% | 16.26% |
| **Russell 1000<sup>®</sup> Index** | 17.37% | 13.59% | 14.59% |
| **Russell 1000<sup>®</sup> Growth Index** | 18.56% | 15.32% | 18.13% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$2629729 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;32 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$13985 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;41% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 13.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 11.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 10.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 6.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 6.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Broadcom, Inc. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 4.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;ServiceNow, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;IDEXX Laboratories, Inc. | 2.1% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_40917.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Large Cap Growth Fund

#### Class N / LCGNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Large Cap Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Large Cap Growth Fund Class N | $95 | 0.90% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 11.36% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 1000<sup>®</sup> Growth Index (the "Index"), which returned 18.56% and underperformed the Russell 1000<sup>®</sup> Index, a broad measure of market performance, which returned 17.37%.

The Fund lagged the return of its benchmark in the full year period, driven by stock-specific dynamics and style headwinds. Information Technology, including our positions in ServiceNow, Tyler Technologies and Salesforce, as well as not owning Palantir Technologies, detracted from returns. Other detractors included Chipotle Mexican Grill (Consumer Discretionary) and UnitedHealth Group (Health Care). From a style perspective, and since the market trough on April 8th, stocks with higher fundamental volatility and higher beta significantly outperformed, creating a headwind to relative performance given our focus on companies with more durable growth. The top contributors for the period included IDEXX Laboratories (Health Care), Lam Research (Information Technology), Broadcom (Information Technology), Uber Technologies (Industrials) and Monster Beverage (Consumer Staples). Not owning Home Depot (Consumer Discretionary) and Adobe (Information Technology) were also tailwinds to performance for the period.

#### TOP PERFORMANCE CONTRIBUTORS
**IDEXX Laboratories** is a global leader in pet healthcare diagnostics. The stock outperformed as IDEXX delivered strong top- and bottom-line growth during the period, driven by strong performance from its high-margin Companion Animal Group (CAG), which achieved a record number of premium instrument placements in the quarter. IDEXX continues to introduce new testing categories and advanced technology that we believe sets the standard for the industry.

**Broadcom** designs, develops, and manufactures a wide range of semiconductor and infrastructure software products. Outperformance during the period was supported by strength in artificial intelligence ("AI") related demand, ethernet networking, and software. While AI infrastructure demand remains a core growth driver, Broadcom is also seeing increased inference activity among key customers helping to drive growth.

#### TOP PERFORMANCE DETRACTORS
**ServiceNow** is a provider of cloud-based service management and business management solutions. Despite delivering solid operational execution and strong subscription growth, shares lagged during the period as concerns over potential AI disruption hindered the valuations of many software-related companies. However, we feel ServiceNow is well positioned to benefit from AI as they embed AI capabilities into existing workflows and introduce new offerings.

**Chipotle Mexican Grill** is a fast-casual restaurant chain that operates thousands of company-owned locations across North America and select international markets. Shares lagged during the period as same store sales growth fell short of expectations, driven by a decline in transactions, and a reduction in forward-looking revenue guidance by management. While uncertainty remains with respect to timing around a recovery in traffic, restaurant level margins remain healthy, with continued operational efficiencies ahead.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_40907.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Large Cap Growth Fund Class N** | 11.36% | 11.11% | 15.96% |
| **Russell 1000<sup>®</sup> Index** | 17.37% | 13.59% | 14.59% |
| **Russell 1000<sup>®</sup> Growth Index** | 18.56% | 15.32% | 18.13% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$2629729 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;32 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$13985 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;41% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 13.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 11.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 10.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 6.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 6.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Broadcom, Inc. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 4.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;ServiceNow, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;IDEXX Laboratories, Inc. | 2.1% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_40893.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Large Cap Growth Fund

#### Class R6 / LCGJX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Large Cap Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Large Cap Growth Fund Class R6 | $64 | 0.60% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 11.71% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 1000<sup>®</sup> Growth Index (the "Index"), which returned 18.56% and underperformed the Russell 1000<sup>®</sup> Index, a broad measure of market performance, which returned 17.37%.

The Fund lagged the return of its benchmark in the full year period, driven by stock-specific dynamics and style headwinds. Information Technology, including our positions in ServiceNow, Tyler Technologies and Salesforce, as well as not owning Palantir Technologies, detracted from returns. Other detractors included Chipotle Mexican Grill (Consumer Discretionary) and UnitedHealth Group (Health Care). From a style perspective, and since the market trough on April 8th, stocks with higher fundamental volatility and higher beta significantly outperformed, creating a headwind to relative performance given our focus on companies with more durable growth. The top contributors for the period included IDEXX Laboratories (Health Care), Lam Research (Information Technology), Broadcom (Information Technology), Uber Technologies (Industrials) and Monster Beverage (Consumer Staples). Not owning Home Depot (Consumer Discretionary) and Adobe (Information Technology) were also tailwinds to performance for the period.

#### TOP PERFORMANCE CONTRIBUTORS
**IDEXX Laboratories** is a global leader in pet healthcare diagnostics. The stock outperformed as IDEXX delivered strong top- and bottom-line growth during the period, driven by strong performance from its high-margin Companion Animal Group (CAG), which achieved a record number of premium instrument placements in the quarter. IDEXX continues to introduce new testing categories and advanced technology that we believe sets the standard for the industry.

**Broadcom** designs, develops, and manufactures a wide range of semiconductor and infrastructure software products. Outperformance during the period was supported by strength in artificial intelligence ("AI") related demand, ethernet networking, and software. While AI infrastructure demand remains a core growth driver, Broadcom is also seeing increased inference activity among key customers helping to drive growth.

#### TOP PERFORMANCE DETRACTORS
**ServiceNow** is a provider of cloud-based service management and business management solutions. Despite delivering solid operational execution and strong subscription growth, shares lagged during the period as concerns over potential AI disruption hindered the valuations of many software-related companies. However, we feel ServiceNow is well positioned to benefit from AI as they embed AI capabilities into existing workflows and introduce new offerings.

**Chipotle Mexican Grill** is a fast-casual restaurant chain that operates thousands of company-owned locations across North America and select international markets. Shares lagged during the period as same store sales growth fell short of expectations, driven by a decline in transactions, and a reduction in forward-looking revenue guidance by management. While uncertainty remains with respect to timing around a recovery in traffic, restaurant level margins remain healthy, with continued operational efficiencies ahead.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_40980.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **Since Inception** |
| **Large Cap Growth Fund Class R6** | 11.71% | 11.45% | 15.95% |
| **Russell 1000<sup>®</sup> Index** | 17.37% | 13.59% | 15.08% |
| **Russell 1000<sup>®</sup> Growth Index** | 18.56% | 15.32% | 19.05% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$2629729 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;32 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$13985 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;41% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 13.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 11.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 10.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 6.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 6.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Broadcom, Inc. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 4.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;ServiceNow, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;IDEXX Laboratories, Inc. | 2.1% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_40965.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Mid Cap Value Fund

#### Class I / WVMIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Mid Cap Value Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Mid Cap Value Fund Class I | $78 | 0.75% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 7.33% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell Midcap<sup>®</sup> Value Index, which returned 11.05% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by poor stock selection due to the Fund's relative underperformance in the Financials and Information Technology sectors. Despite negative performance, the Fund had positive stock selection in 7 of the 11 Global Industry Classification Standard economic sectors during the period. The Fund's positive stock selections were additive to relative performance in the Materials, Industrials, and Utilities sectors.

#### TOP PERFORMANCE CONTRIBUTORS
**Royal Gold, Inc.** acquires and manages precious metal streams, royalties, and similar interests. Royal Gold has benefited from a mixture of a favorable commodity pricing environment as well as strong momentum among gold equities.

**Flex Ltd.** operates as an electronics manufacturing services company, which designs and develops original design manufacturing products for various end markets. Flex has benefitted from continuous datacenter buildout, which has the opportunity for further margin expansion.

**Globus Medical, Inc.** sells spinal implants, robots, biologics, and neuromonitoring equipment. Globus benefited from their effective NEVRO integration and broad strength across spinal implants.

#### TOP PERFORMANCE DETRACTORS
**ON Semiconductor Corp.** engages in the provision of power and sensing solutions, and technologies from electrification of the automotive industry. ON's utilization rate and margins have remained pressured due to broad weakness across automotive and industrial end markets for their products.

**Centene Corp.** provides multi-line healthcare solutions to individuals across all states and internationally. Centene has struggled mainly due to managed care plans, which are experiencing unprecedented medical cost pressures caused by changes in the underlying risk pools and inadequate reimbursement.

**Teleflex Inc.** is a medical technology company, which services hospitals & health care providers as well as home health. Teleflex announced a revenue and guidance miss, vascular acquisition, planned corporate spin-off as well as a CFO departure in short order, which was not well received by the market.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41020.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Mid Cap Value Fund Class I** | 7.33% | 6.03% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 14.26% |
| **Russell Midcap<sup>®</sup> Value Index** | 11.05% | 7.79% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1353 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;57 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$0 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;28% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Globus Medical, Inc. | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Kirby Corporation | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;State Street Corporation | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Royal Gold, Inc. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Toll Brothers, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Donaldson Company, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Entergy Corp. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Dover Corporation | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Cencora, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Willis Towers Watson PLC | 2.1% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_40989.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Mid Cap Value Fund

#### Class R6 / WVMRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Mid Cap Value Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Mid Cap Value Fund Class R6 | $73 | 0.70% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 7.39% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell Midcap<sup>®</sup> Value Index, which returned 11.05% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by poor stock selection due to the Fund's relative underperformance in the Financials and Information Technology sectors. Despite negative performance, the Fund had positive stock selection in 7 of the 11 Global Industry Classification Standard economic sectors during the period. The Fund's positive stock selections were additive to relative performance in the Materials, Industrials, and Utilities sectors.

#### TOP PERFORMANCE CONTRIBUTORS
**Royal Gold, Inc.** acquires and manages precious metal streams, royalties, and similar interests. Royal Gold has benefited from a mixture of a favorable commodity pricing environment as well as strong momentum among gold equities.

**Flex Ltd.** operates as an electronics manufacturing services company, which designs and develops original design manufacturing products for various end markets. Flex has benefitted from continuous datacenter buildout, which has the opportunity for further margin expansion.

**Globus Medical, Inc.** sells spinal implants, robots, biologics, and neuromonitoring equipment. Globus benefited from their effective NEVRO integration and broad strength across spinal implants.

#### TOP PERFORMANCE DETRACTORS
**ON Semiconductor Corp.** engages in the provision of power and sensing solutions, and technologies from electrification of the automotive industry. ON's utilization rate and margins have remained pressured due to broad weakness across automotive and industrial end markets for their products.

**Centene Corp.** provides multi-line healthcare solutions to individuals across all states and internationally. Centene has struggled mainly due to managed care plans, which are experiencing unprecedented medical cost pressures caused by changes in the underlying risk pools and inadequate reimbursement.

**Teleflex Inc.** is a medical technology company, which services hospitals & health care providers as well as home health. Teleflex announced a revenue and guidance miss, vascular acquisition, planned corporate spin-off as well as a CFO departure in short order, which was not well received by the market.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41052.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Mid Cap Value Fund Class R6** | 7.39% | 6.08% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 14.26% |
| **Russell Midcap<sup>®</sup> Value Index** | 11.05% | 7.79% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1353 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;57 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$0 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;28% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Globus Medical, Inc. | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Kirby Corporation | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;State Street Corporation | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Royal Gold, Inc. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Toll Brothers, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Donaldson Company, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Entergy Corp. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Dover Corporation | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Cencora, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Willis Towers Watson PLC | 2.1% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41036.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small-Mid Cap Core Fund

#### Class I / WBCIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small-Mid Cap Core Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small-Mid Cap Core Fund Class I | $96 | 0.95% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 1.27% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2500<sup>™</sup> Index, which returned 11.91% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a combination of style headwinds and stock-specific dynamics. Notably, most of the underperformance occurred in the period since the market trough on April 8th through October 15th, during which the Russell 2500<sup>®</sup> Index advanced by over 37%. In this market environment, unprofitable companies and stocks with higher fundamental volatility and higher beta dramatically outperformed, creating a headwind for the strategy given our typical underweight to unprofitable companies and bias towards more consistent business models. From a stock-specific perspective, selection in Health Care, Consumer Staples and Industrials was a detractor in the period. Our top individual detractors included ACV Auctions (Industrials), New Fortress Energy (Energy), Primo Brands (Consumer Staples), Baldwin Insurance Group (Financials) and Willscot Holdings (Industrials). The Fund's top individual contributors included Ciena Corp (Information Technology), Exact Sciences (Health Care), Talen Energy (Utilities), Coherent (Information Technology) and Mercury Systems (Industrials).

#### TOP PERFORMANCE CONTRIBUTORS
**Ciena Corporation** designs and delivers high-performance networking equipment, software and services. The company reported better-than-expected earnings with favorable guidance citing a record backlog and accelerating artificial intelligence-driven cloud demand. We continue to believe Ciena is poised to deliver durable growth, driven by a favorable competitive landscape and secular demand acceleration fueled by a multi-year AI inference networking cycle.

**Exact Sciences** is a molecular diagnostic company. The company agreed to be acquired by Abbott for a significant premium to the prior closing price. We liquidated our position following the announcement.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. ACV Actions, endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**New Fortress Energy** develops, finances and constructs liquefied natural gas assets and related infrastructure. Shares were pressured as the likelihood of the company winning a material long-term gas contract with Puerto Rico declined. We liquidated our position as increased uncertainty reduced our confidence in our long-term thesis.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41092.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **Since Inception** |
| **Small-Mid Cap Core Fund Class I** | 1.27% | 6.17% | 9.25% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 15.37% |
| **Russell 2500<sup>™</sup> Index** | 11.91% | 7.26% | 10.33% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$123129 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;88 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$911 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;81% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Diebold Nixdorf, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Ciena Corporation | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Everest Group Ltd. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Onto Innovation, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Jones Lang LaSalle Incorporated | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;IDACORP, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Talen Energy Corporation | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Doximity, Inc. | 1.5% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41061.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small-Mid Cap Core Fund

#### Class R6 / WBCRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small-Mid Cap Core Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small-Mid Cap Core Fund Class R6 | $91 | 0.90% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 1.33% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2500<sup>™</sup> Index, which returned 11.91% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a combination of style headwinds and stock-specific dynamics. Notably, most of the underperformance occurred in the period since the market trough on April 8th through October 15th, during which the Russell 2500<sup>®</sup> Index advanced by over 37%. In this market environment, unprofitable companies and stocks with higher fundamental volatility and higher beta dramatically outperformed, creating a headwind for the strategy given our typical underweight to unprofitable companies and bias towards more consistent business models. From a stock-specific perspective, selection in Health Care, Consumer Staples and Industrials was a detractor in the period. Our top individual detractors included ACV Auctions (Industrials), New Fortress Energy (Energy), Primo Brands (Consumer Staples), Baldwin Insurance Group (Financials) and Willscot Holdings (Industrials). The Fund's top individual contributors included Ciena Corp (Information Technology), Exact Sciences (Health Care), Talen Energy (Utilities), Coherent (Information Technology) and Mercury Systems (Industrials).

#### TOP PERFORMANCE CONTRIBUTORS
**Ciena Corporation** designs and delivers high-performance networking equipment, software and services. The company reported better-than-expected earnings with favorable guidance citing a record backlog and accelerating artificial intelligence-driven cloud demand. We continue to believe Ciena is poised to deliver durable growth, driven by a favorable competitive landscape and secular demand acceleration fueled by a multi-year AI inference networking cycle.

**Exact Sciences** is a molecular diagnostic company. The company agreed to be acquired by Abbott for a significant premium to the prior closing price. We liquidated our position following the announcement.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. ACV Actions, endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**New Fortress Energy** develops, finances and constructs liquefied natural gas assets and related infrastructure. Shares were pressured as the likelihood of the company winning a material long-term gas contract with Puerto Rico declined. We liquidated our position as increased uncertainty reduced our confidence in our long-term thesis.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41123.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **Since Inception** |
| **Small-Mid Cap Core Fund Class R6** | 1.33% | 6.23% | 9.30% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 15.37% |
| **Russell 2500<sup>™</sup> Index** | 11.91% | 7.26% | 10.33% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$123129 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;88 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$911 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;81% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Diebold Nixdorf, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Ciena Corporation | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Everest Group Ltd. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Onto Innovation, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Jones Lang LaSalle Incorporated | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;IDACORP, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Talen Energy Corporation | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Doximity, Inc. | 1.5% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41109.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small-Mid Cap Growth Fund

#### Class I / WSMDX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small-Mid Cap Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small-Mid Cap Growth Fund Class I | $99 | 0.99% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 0.62% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2500<sup>™</sup> Growth Index, which returned 10.31% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a combination of style headwinds and stock-specific dynamics. Underperformance can be attributed primarily to the period since the market trough on April 8th through October 15th, during which the Russell 2500<sup>®</sup> Growth Index advanced by over 45%. This speculative rally favored unprofitable companies and stocks with higher fundamental volatility and higher beta, creating a headwind for the strategy given our typical underweight to unprofitable companies and bias towards more consistent business models. Notably, the portfolio outperformed earlier in the year when its benchmark declined by over 23% and significantly outperformed in the period since the market peak on October 15, 2025, as market returns began to normalize and style headwinds eased. Relative performance in the year was directionally consistent with the historical performance profile of the strategy. From a stock-specific perspective, selection in Consumer Staples and Industrials was a detractor in the period. Our top individual detractors included Primo Brands (Consumer Staples), New Fortress Energy (Energy), e.l.f Beauty (Consumer Staples), BellRing Brands (Consumer Staples) and Freshpet (Consumer Staples). Our top individual contributors included Talen Energy (Utilities), Cameco (Energy) and Insmed (Health Care). Stock selection in Information Technology, including our positions in Ciena Corp and Coherent, was also a positive contributor.

#### TOP PERFORMANCE CONTRIBUTORS
**Ciena Corporation** designs and delivers high-performance networking equipment, software and services. The company reported better-than-expected earnings with favorable guidance citing a record backlog and accelerating artificial intelligence driven cloud demand. We continue to believe Ciena is poised to deliver durable growth, driven by a favorable competitive landscape and secular demand acceleration fueled by a multi-year AI inference networking cycle.

**Talen Energy** is an integrated independent power producer. Talen announced its acquisition of two high quality assets, positioning the company to sign additional data center deals. We continue to believe the company is well-positioned for material earnings acceleration over the long term.

#### TOP PERFORMANCE DETRACTORS
**Primo Brands**, a leading provider of bottled water through retail and direct delivery channels lagged as merger integration challenges pressured earnings. We continue to believe the increasing use of bottled and purified water over tap water and carbonated soft drinks, as well as Primo's significant advantages in scale and operational efficiency versus competitors, will drive growth over the long term.

**New Fortress Energy** develops, finances and constructs liquefied natural gas assets and related infrastructure. Shares were pressured as the likelihood of the company winning a material long-term gas contract with Puerto Rico declined. We liquidated our position as increased uncertainty reduced our confidence in our long-term thesis.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41195.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Small-Mid Cap Growth Fund Class I** | 0.62% | 2.06% | 9.95% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 14.29% |
| **Russell 2500<sup>™</sup> Growth Index** | 10.31% | 2.98% | 10.55% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1252951 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;77 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$12197 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;57% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Insmed, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Ciena Corporation | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Pure Storage, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Onto Innovation, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Talen Energy Corporation | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Globus Medical, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mueller Industries, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Madrigal Pharmaceuticals, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Doximity, Inc. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Everest Group Ltd. | 1.7% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41181.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small-Mid Cap Growth Fund

#### Class N / WSMNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small-Mid Cap Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small-Mid Cap Growth Fund Class N | $124 | 1.24% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 0.37% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2500<sup>™</sup> Growth Index, which returned 10.31% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a combination of style headwinds and stock-specific dynamics. Underperformance can be attributed primarily to the period since the market trough on April 8th through October 15th, during which the Russell 2500<sup>®</sup> Growth Index advanced by over 45%. This speculative rally favored unprofitable companies and stocks with higher fundamental volatility and higher beta, creating a headwind for the strategy given our typical underweight to unprofitable companies and bias towards more consistent business models. Notably, the portfolio outperformed earlier in the year when its benchmark declined by over 23% and significantly outperformed in the period since the market peak on October 15, 2025, as market returns began to normalize and style headwinds eased. Relative performance in the year was directionally consistent with the historical performance profile of the strategy. From a stock-specific perspective, selection in Consumer Staples and Industrials was a detractor in the period. Our top individual detractors included Primo Brands (Consumer Staples), New Fortress Energy (Energy), e.l.f Beauty (Consumer Staples), BellRing Brands (Consumer Staples) and Freshpet (Consumer Staples). Our top individual contributors included Talen Energy (Utilities), Cameco (Energy) and Insmed (Health Care). Stock selection in Information Technology, including our positions in Ciena Corp and Coherent, was also a positive contributor.

#### TOP PERFORMANCE CONTRIBUTORS
**Ciena Corporation** designs and delivers high-performance networking equipment, software and services. The company reported better-than-expected earnings with favorable guidance citing a record backlog and accelerating artificial intelligence driven cloud demand. We continue to believe Ciena is poised to deliver durable growth, driven by a favorable competitive landscape and secular demand acceleration fueled by a multi-year AI inference networking cycle.

**Talen Energy** is an integrated independent power producer. Talen announced its acquisition of two high quality assets, positioning the company to sign additional data center deals. We continue to believe the company is well-positioned for material earnings acceleration over the long term.

#### TOP PERFORMANCE DETRACTORS
**Primo Brands**, a leading provider of bottled water through retail and direct delivery channels lagged as merger integration challenges pressured earnings. We continue to believe the increasing use of bottled and purified water over tap water and carbonated soft drinks, as well as Primo's significant advantages in scale and operational efficiency versus competitors, will drive growth over the long term.

**New Fortress Energy** develops, finances and constructs liquefied natural gas assets and related infrastructure. Shares were pressured as the likelihood of the company winning a material long-term gas contract with Puerto Rico declined. We liquidated our position as increased uncertainty reduced our confidence in our long-term thesis.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_41164.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Small-Mid Cap Growth Fund Class N** | 0.37% | 1.80% | 9.67% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 14.29% |
| **Russell 2500<sup>™</sup> Growth Index** | 10.31% | 2.98% | 10.55% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1252951 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;77 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$12197 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;57% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Insmed, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Ciena Corporation | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Pure Storage, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Onto Innovation, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Talen Energy Corporation | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Globus Medical, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mueller Industries, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Madrigal Pharmaceuticals, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Doximity, Inc. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Everest Group Ltd. | 1.7% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41133.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small-Mid Cap Growth Fund

#### Class R6 / WSMRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small-Mid Cap Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small-Mid Cap Growth Fund Class R6 | $94 | 0.94% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 0.69% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2500<sup>™</sup> Growth Index, which returned 10.31% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a combination of style headwinds and stock-specific dynamics. Underperformance can be attributed primarily to the period since the market trough on April 8th through October 15th, during which the Russell 2500<sup>®</sup> Growth Index advanced by over 45%. This speculative rally favored unprofitable companies and stocks with higher fundamental volatility and higher beta, creating a headwind for the strategy given our typical underweight to unprofitable companies and bias towards more consistent business models. Notably, the portfolio outperformed earlier in the year when its benchmark declined by over 23% and significantly outperformed in the period since the market peak on October 15, 2025, as market returns began to normalize and style headwinds eased. Relative performance in the year was directionally consistent with the historical performance profile of the strategy. From a stock-specific perspective, selection in Consumer Staples and Industrials was a detractor in the period. Our top individual detractors included Primo Brands (Consumer Staples), New Fortress Energy (Energy), e.l.f Beauty (Consumer Staples), BellRing Brands (Consumer Staples) and Freshpet (Consumer Staples). Our top individual contributors included Talen Energy (Utilities), Cameco (Energy) and Insmed (Health Care). Stock selection in Information Technology, including our positions in Ciena Corp and Coherent, was also a positive contributor.

#### TOP PERFORMANCE CONTRIBUTORS
**Ciena Corporation** designs and delivers high-performance networking equipment, software and services. The company reported better-than-expected earnings with favorable guidance citing a record backlog and accelerating artificial intelligence driven cloud demand. We continue to believe Ciena is poised to deliver durable growth, driven by a favorable competitive landscape and secular demand acceleration fueled by a multi-year AI inference networking cycle.

**Talen Energy** is an integrated independent power producer. Talen announced its acquisition of two high quality assets, positioning the company to sign additional data center deals. We continue to believe the company is well-positioned for material earnings acceleration over the long term.

#### TOP PERFORMANCE DETRACTORS
**Primo Brands**, a leading provider of bottled water through retail and direct delivery channels lagged as merger integration challenges pressured earnings. We continue to believe the increasing use of bottled and purified water over tap water and carbonated soft drinks, as well as Primo's significant advantages in scale and operational efficiency versus competitors, will drive growth over the long term.

**New Fortress Energy** develops, finances and constructs liquefied natural gas assets and related infrastructure. Shares were pressured as the likelihood of the company winning a material long-term gas contract with Puerto Rico declined. We liquidated our position as increased uncertainty reduced our confidence in our long-term thesis.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41237.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **Since Inception** |
| **Small-Mid Cap Growth Fund Class R6** | 0.69% | 2.11% | 7.20% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 14.69% |
| **Russell 2500<sup>™</sup> Growth Index** | 10.31% | 2.98% | 8.97% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1252951 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;77 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$12197 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;57% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Insmed, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Ciena Corporation | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Pure Storage, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Onto Innovation, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Talen Energy Corporation | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Globus Medical, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mueller Industries, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Madrigal Pharmaceuticals, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Doximity, Inc. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Everest Group Ltd. | 1.7% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41205.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small-Mid Cap Value Fund

#### Class I / ISMVX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small-Mid Cap Value Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small-Mid Cap Value Fund Class I | $86 | 0.85% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 3.16% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2500<sup>®</sup> Value Index, which returned 12.73% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by poor sector stock selection due to the Fund's relative underperformance in the Financials, Health Care, and Energy sectors. Despite negative performance, the Fund had positive sector allocation 7 of the 11 Global Industry Classification Standard economic sectors during the period.

#### TOP PERFORMANCE CONTRIBUTORS
**Tower Semiconductor Ltd.** is an independent foundry providing semiconductor integrated circuits manufacturing and related design services. Tower Semiconductor has benefited from the growing success in their Silicon Photonics business, which has been used in data centers to fuel artificial intelligence.

**Flex, Ltd.** operates as an electronics manufacturing services company, which designs and develops original design manufacturing products for various end markets. Flex has benefited from continuous datacenter buildout, which has the opportunity for further margin expansion.

**Royal Gold, Inc.** acquires and manages precious metal streams, royalties, and similar interests. Royal Gold has benefited from a mixture of a favorable commodity pricing environment as well as strong momentum among gold equities.

#### TOP PERFORMANCE DETRACTORS
**Acadia Healthcare Co, Inc.** is a behavioral health provider operating the full spectrum of behavioral health facilities. Acadia has suffered from lower than expected volumes, select facility closures, and greater payer scrutiny from insurance companies.

**Compass Diversified Holdings** is an investment holding company, which acquires controlling interests in small-middle market businesses. Compass Diversified suffered from an accounting irregularity in its largest business.

**TriNet Group, Inc.** engages in the provision of comprehensive human resources solutions for small and medium-size businesses. TriNet suffered from the market's pessimism regarding the macroeconomic employment outlook as well as below consensus growth due to healthcare cost headwinds.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41267.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Small-Mid Cap Value Fund Class I** | 3.16% | 6.35% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 21.85% |
| **Russell 2500<sup>®</sup> Value Index** | 12.73% | 14.66% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$3457 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;82 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$0 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;40% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Tower Semiconductor Ltd. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Eastern Bankshares, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;SouthState Bank Corporation | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Royal Gold, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Banking System, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Commercial Metals Co. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Globus Medical, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Flex Ltd. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atmus Filtration Technologies Inc. | 1.6% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41253.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small-Mid Cap Value Fund

#### Class R6 / RSMVX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small-Mid Cap Value Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small-Mid Cap Value Fund Class R6 | $81 | 0.80% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 3.21% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2500<sup>®</sup> Value Index, which returned 12.73% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by poor sector stock selection due to the Fund's relative underperformance in the Financials, Health Care, and Energy sectors. Despite negative performance, the Fund had positive sector allocation 7 of the 11 Global Industry Classification Standard economic sectors during the period.

#### TOP PERFORMANCE CONTRIBUTORS
**Tower Semiconductor Ltd.** is an independent foundry providing semiconductor integrated circuits manufacturing and related design services. Tower Semiconductor has benefited from the growing success in their Silicon Photonics business, which has been used in data centers to fuel artificial intelligence.

**Flex, Ltd.** operates as an electronics manufacturing services company, which designs and develops original design manufacturing products for various end markets. Flex has benefited from continuous datacenter buildout, which has the opportunity for further margin expansion.

**Royal Gold, Inc.** acquires and manages precious metal streams, royalties, and similar interests. Royal Gold has benefited from a mixture of a favorable commodity pricing environment as well as strong momentum among gold equities.

#### TOP PERFORMANCE DETRACTORS
**Acadia Healthcare Co, Inc.** is a behavioral health provider operating the full spectrum of behavioral health facilities. Acadia has suffered from lower than expected volumes, select facility closures, and greater payer scrutiny from insurance companies.

**Compass Diversified Holdings** is an investment holding company, which acquires controlling interests in small-middle market businesses. Compass Diversified suffered from an accounting irregularity in its largest business.

**TriNet Group, Inc.** engages in the provision of comprehensive human resources solutions for small and medium-size businesses. TriNet suffered from the market's pessimism regarding the macroeconomic employment outlook as well as below consensus growth due to healthcare cost headwinds.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41307.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Small-Mid Cap Value Fund Class R6** | 3.21% | 6.38% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 21.85% |
| **Russell 2500<sup>®</sup> Value Index** | 12.73% | 14.66% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$3457 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;82 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$0 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;40% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Tower Semiconductor Ltd. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Eastern Bankshares, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;SouthState Bank Corporation | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Royal Gold, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Banking System, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Commercial Metals Co. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Globus Medical, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Flex Ltd. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atmus Filtration Technologies Inc. | 1.6% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41277.jpg)

#### Availability of Additional Infor mation
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small Cap Growth Fund

#### Class I / WBSIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small Cap Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small Cap Growth Fund Class I | $100 | 0.99% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 3.01% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2000<sup>®</sup> Growth Index, which returned 13.01% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund underperformed the return of its benchmark, driven by a combination of style headwinds and stock-specific dynamics. Notably, most of the underperformance occurred between April 8th and October 15th, as the Russell 2000<sup>®</sup> Growth Index surged nearly 50%. This speculative rally favored higher-beta, more volatile and momentum-driven stocks, creating a headwind for our strategy which focuses on consistent business models. Stock selection in the Health Care and Industrials sectors, including our positions in ACV Auctions and WillScot Holdings, detracted from performance. Other individual detractors included Primo Brands (Consumer Staples), Credo Technology (Information Technology), and New Fortress Energy (Energy). The top individual contributors included Lumentum (Information Technology), Amicus Therapeutics (Health Care), Mercury Systems (Industrials), CECO Environmental Corp. (Industrials), and Alignment Health Care (Health Care).

#### TOP PERFORMANCE CONTRIBUTORS
**Lumentum**, a leading provider of optical and photonics products, outperformed due to strong earnings results and issued guidance that was meaningfully ahead of expectations, driven by broad-based artificial intelligence ("AI") optics strength across data center and long-haul applications. We continue to believe the company poised for significant growth due to the increasing demand for high-speed optical interconnects in AI data centers and a broader recovery across its other markets.

**Amicus Therapeutics**, a commercial-stage rare disease biotechnology company focused on novel therapeutics for rare diseases, agreed to be acquired by BioMarin for a premium relative to its closing price. Leading into the deal, investor sentiment had been improving as Amicus demonstrated strong commercial execution, with continued growth from its Fabry and Pompe disease franchises. We exited the position following the deal announcement.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. The stock underperformed as the company endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**Primo Brands**, a leading provider of bottled water through retail and direct delivery channels, lagged as merger integration challenges pressured earnings. We continue to believe the increasing use of bottled and purified water over tap water and carbonated soft drinks, as well as Primo's significant advantages in scale and operational efficiency versus competitors, will drive growth over the long term.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41380.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Small Cap Growth Fund Class I** | 3.01% | 4.95% | 12.38% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 14.29% |
| **Russell 2000<sup>®</sup> Growth Index** | 13.01% | 3.18% | 9.57% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$987100 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;91 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$7646 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;94% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Diebold Nixdorf, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Brink's Co. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Lumentum Holdings Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Twist Bioscience Corp. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Establishment Labs Holdings, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Champion Homes, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rush Street Interactive, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Balchem Corp. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alignment Healthcare, Inc. | 1.6% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41349.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small Cap Growth Fund

#### Class N / WBSNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small Cap Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small Cap Growth Fund Class N | $126 | 1.24% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 2.74% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2000<sup>®</sup> Growth Index, which returned 13.01% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund underperformed the return of its benchmark, driven by a combination of style headwinds and stock-specific dynamics. Notably, most of the underperformance occurred between April 8th and October 15th, as the Russell 2000<sup>®</sup> Growth Index surged nearly 50%. This speculative rally favored higher-beta, more volatile and momentum-driven stocks, creating a headwind for our strategy which focuses on consistent business models. Stock selection in the Health Care and Industrials sectors, including our positions in ACV Auctions and WillScot Holdings, detracted from performance. Other individual detractors included Primo Brands (Consumer Staples), Credo Technology (Information Technology), and New Fortress Energy (Energy). The top individual contributors included Lumentum (Information Technology), Amicus Therapeutics (Health Care), Mercury Systems (Industrials), CECO Environmental Corp. (Industrials), and Alignment Health Care (Health Care).

#### TOP PERFORMANCE CONTRIBUTORS
**Lumentum**, a leading provider of optical and photonics products, outperformed due to strong earnings results and issued guidance that was meaningfully ahead of expectations, driven by broad-based artificial intelligence ("AI") optics strength across data center and long-haul applications. We continue to believe the company poised for significant growth due to the increasing demand for high-speed optical interconnects in AI data centers and a broader recovery across its other markets.

**Amicus Therapeutics**, a commercial-stage rare disease biotechnology company focused on novel therapeutics for rare diseases, agreed to be acquired by BioMarin for a premium relative to its closing price. Leading into the deal, investor sentiment had been improving as Amicus demonstrated strong commercial execution, with continued growth from its Fabry and Pompe disease franchises. We exited the position following the deal announcement.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. The stock underperformed as the company endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**Primo Brands**, a leading provider of bottled water through retail and direct delivery channels, lagged as merger integration challenges pressured earnings. We continue to believe the increasing use of bottled and purified water over tap water and carbonated soft drinks, as well as Primo's significant advantages in scale and operational efficiency versus competitors, will drive growth over the long term.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_41340.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Small Cap Growth Fund Class N** | 2.74% | 4.68% | 12.10% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 14.29% |
| **Russell 2000<sup>®</sup> Growth Index** | 13.01% | 3.18% | 9.57% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$987100 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;91 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$7646 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;94% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Diebold Nixdorf, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Brink's Co. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Lumentum Holdings Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Twist Bioscience Corp. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Establishment Labs Holdings, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Champion Homes, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rush Street Interactive, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Balchem Corp. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alignment Healthcare, Inc. | 1.6% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41325.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small Cap Growth Fund

#### Class R6 / WBSRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small Cap Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small Cap Growth Fund Class R6 | $95 | 0.94% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 3.05% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2000<sup>®</sup> Growth Index, which returned 13.01% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund underperformed the return of its benchmark, driven by a combination of style headwinds and stock-specific dynamics. Notably, most of the underperformance occurred between April 8th and October 15th, as the Russell 2000<sup>®</sup> Growth Index surged nearly 50%. This speculative rally favored higher-beta, more volatile and momentum-driven stocks, creating a headwind for our strategy which focuses on consistent business models. Stock selection in the Health Care and Industrials sectors, including our positions in ACV Auctions and WillScot Holdings, detracted from performance. Other individual detractors included Primo Brands (Consumer Staples), Credo Technology (Information Technology), and New Fortress Energy (Energy). The top individual contributors included Lumentum (Information Technology), Amicus Therapeutics (Health Care), Mercury Systems (Industrials), CECO Environmental Corp. (Industrials), and Alignment Health Care (Health Care).

#### TOP PERFORMANCE CONTRIBUTORS
**Lumentum**, a leading provider of optical and photonics products, outperformed due to strong earnings results and issued guidance that was meaningfully ahead of expectations, driven by broad-based artificial intelligence ("AI") optics strength across data center and long-haul applications. We continue to believe the company poised for significant growth due to the increasing demand for high-speed optical interconnects in AI data centers and a broader recovery across its other markets.

**Amicus Therapeutics**, a commercial-stage rare disease biotechnology company focused on novel therapeutics for rare diseases, agreed to be acquired by BioMarin for a premium relative to its closing price. Leading into the deal, investor sentiment had been improving as Amicus demonstrated strong commercial execution, with continued growth from its Fabry and Pompe disease franchises. We exited the position following the deal announcement.

#### TOP PERFORMANCE DETRACTORS
**ACV Auctions** operates an online marketplace for wholesale used vehicle transactions. The stock underperformed as the company endured continued weakness in the market for dealer-to-dealer wholesale auto transactions. We continue to believe ACV Auctions has a long runway for growth in the industry as it offers a superior, efficient, and cost-effective way to purchase vehicles as compared to physical auctions.

**Primo Brands**, a leading provider of bottled water through retail and direct delivery channels, lagged as merger integration challenges pressured earnings. We continue to believe the increasing use of bottled and purified water over tap water and carbonated soft drinks, as well as Primo's significant advantages in scale and operational efficiency versus competitors, will drive growth over the long term.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41412.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **Since Inception** |
| **Small Cap Growth Fund Class R6** | 3.05% | 5.01% | 9.40% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 14.69% |
| **Russell 2000<sup>®</sup> Growth Index** | 13.01% | 3.18% | 8.23% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$987100 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;91 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$7646 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;94% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Diebold Nixdorf, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Brink's Co. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Lumentum Holdings Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Twist Bioscience Corp. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Establishment Labs Holdings, Inc. | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Champion Homes, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rush Street Interactive, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Balchem Corp. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alignment Healthcare, Inc. | 1.6% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41397.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small Cap Value Fund

#### Class I / ICSCX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small Cap Value Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small Cap Value Fund Class I | $90 | 0.89% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 2.91% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2000<sup>®</sup> Value Index, which returned 12.59% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a relative underperformance by the Fund's holdings in the Consumer Discretionary sector. The Fund was also negatively impacted by an underweight position and relative underperformance by the Portfolio's holdings in the Health Care and Financials sectors. Despite the underperformance, the Fund was positively impacted by an underweight position and relative outperformance by the Fund's holdings in the Energy sector.

#### TOP PERFORMANCE CONTRIBUTORS
**Tower Semiconductor Ltd.** is an independent foundry providing semiconductor integrated circuits manufacturing and related design services. Tower Semiconductor has benefited from the growing success in their Silicon Photonics business, which has been used in data centers to fuel artificial intelligence ("AI").

**Sanmina Corp.** engages in the provision of integrated manufacturing solutions, components, products and repair, logistics and after-market services. Sanmina has benefited from the continuous data center and AI infrastructure build out, which has allowed the company to potentially reach revenue targets a year earlier than previously expected.

**WNS Holdings Ltd.** engages in the provision of business process management solutions. WNS benefited from improving operational efficiencies in a challenging environment coupled with the closing of its acquisition by Capgemini which offered a significant premium.

#### TOP PERFORMANCE DETRACTORS
**Compass Diversified Holdings** is an investment holding company, which acquires controlling interests in small-middle market businesses. Compass Diversified suffered from an accounting irregularity in its largest business.

**Edgewell Personal Care Co.** operates as a personal care company that manufactures and distributes feminine, infant, skin, pet, suncare, and shaving products. Edgewell has suffered from consistent macroeconomic headwinds including tariffs and an already stretched consumer, which have yet to show signs of relenting.

**Empire State Realty Trust Inc.** operates as a real estate investment trust, which owns, manages, operates, acquires, and repositions office and retail properties. Empire State Realty struggled due to higher New York City Real Estate taxes and other one-time expenses, as well as softer tourism demand, which compressed its operating margin.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41485.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Small Cap Value Fund Class I** | 2.91% | 6.31% | 8.46% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 13.15% | 14.29% |
| **Russell 2000<sup>®</sup> Value Index** | 12.59% | 8.88% | 9.27% |

---

On July 16, 2021, the Fund acquired the assets and assumed the liabilities of the ICM Small Company Portfolio (the "Predecessor Fund") in a reorganization (the "Reorganization"). The Predecessor Fund's (Institutional Class shares) performance and financial history have been adopted by Class I shares of the Fund following the Reorganization. The performance of the Predecessor Fund has not been restated to reflect the annual operating expenses of Class I shares of the Fund. Because the Fund had different fees and expenses than the Predecessor Fund, the Predecessor Fund would therefore have had different performance results if it was subject to the Fund's fees and expenses.

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$919456 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;105 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$8059 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;37% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Banc Of California, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tower Semiconductor Ltd. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Texas Capital Bancshares, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hancock Whitney Corp. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Seacoast Banking Corp. of Florida | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Gulfport Energy Corp. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atlantic Union Bankshares Corp. | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Commercial Metals Co. | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atmus Filtration Technologies Inc. | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41468.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small Cap Value Fund

#### Class N / WBVNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small Cap Value Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small Cap Value Fund Class N | $116 | 1.15% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 2.61% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2000<sup>®</sup> Value Index, which returned 12.59% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a relative underperformance by the Fund's holdings in the Consumer Discretionary sector. The Fund was also negatively impacted by an underweight position and relative underperformance by the Portfolio's holdings in the Health Care and Financials sectors. Despite the underperformance, the Fund was positively impacted by an underweight position and relative outperformance by the Fund's holdings in the Energy sector.

#### TOP PERFORMANCE CONTRIBUTORS
**Tower Semiconductor Ltd.** is an independent foundry providing semiconductor integrated circuits manufacturing and related design services. Tower Semiconductor has benefited from the growing success in their Silicon Photonics business, which has been used in data centers to fuel artificial intelligence ("AI").

**Sanmina Corp.** engages in the provision of integrated manufacturing solutions, components, products and repair, logistics and after-market services. Sanmina has benefited from the continuous data center and AI infrastructure build out, which has allowed the company to potentially reach revenue targets a year earlier than previously expected.

**WNS Holdings Ltd.** engages in the provision of business process management solutions. WNS benefited from improving operational efficiencies in a challenging environment coupled with the closing of its acquisition by Capgemini which offered a significant premium.

#### TOP PERFORMANCE DETRACTORS
**Compass Diversified Holdings** is an investment holding company, which acquires controlling interests in small-middle market businesses. Compass Diversified suffered from an accounting irregularity in its largest business.

**Edgewell Personal Care Co.** operates as a personal care company that manufactures and distributes feminine, infant, skin, pet, suncare, and shaving products. Edgewell has suffered from consistent macroeconomic headwinds including tariffs and an already stretched consumer, which have yet to show signs of relenting.

**Empire State Realty Trust Inc.** operates as a real estate investment trust, which owns, manages, operates, acquires, and repositions office and retail properties. Empire State Realty struggled due to higher New York City Real Estate taxes and other one-time expenses, as well as softer tourism demand, which compressed its operating margin.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_41452.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Small Cap Value Fund Class N** | 2.61% | 2.73% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 11.34% |
| **Russell 2000<sup>®</sup> Value Index** | 12.59% | 5.72% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$919456 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;105 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$8059 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;37% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Banc Of California, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tower Semiconductor Ltd. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Texas Capital Bancshares, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hancock Whitney Corp. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Seacoast Banking Corp. of Florida | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Gulfport Energy Corp. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atlantic Union Bankshares Corp. | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Commercial Metals Co. | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atmus Filtration Technologies Inc. | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41421.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Small Cap Value Fund

#### Class R6 / WBVRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Small Cap Value Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Small Cap Value Fund Class R6 | $81 | 0.80% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 3.01% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the Russell 2000<sup>®</sup> Value Index, which returned 12.59% and underperformed the Russell 3000<sup>®</sup> Index, a broad measure of market performance, which returned 17.15%.

The Fund's underperformance versus its benchmark was driven by a relative underperformance by the Fund's holdings in the Consumer Discretionary sector. The Fund was also negatively impacted by an underweight position and relative underperformance by the Portfolio's holdings in the Health Care and Financials sectors. Despite the underperformance, the Fund was positively impacted by an underweight position and relative outperformance by the Fund's holdings in the Energy sector.

#### TOP PERFORMANCE CONTRIBUTORS
**Tower Semiconductor Ltd.** is an independent foundry providing semiconductor integrated circuits manufacturing and related design services. Tower Semiconductor has benefited from the growing success in their Silicon Photonics business, which has been used in data centers to fuel artificial intelligence ("AI").

**Sanmina Corp.** engages in the provision of integrated manufacturing solutions, components, products and repair, logistics and after-market services. Sanmina has benefited from the continuous data center and AI infrastructure build out, which has allowed the company to potentially reach revenue targets a year earlier than previously expected.

**WNS Holdings Ltd.** engages in the provision of business process management solutions. WNS benefited from improving operational efficiencies in a challenging environment coupled with the closing of its acquisition by Capgemini which offered a significant premium.

#### TOP PERFORMANCE DETRACTORS
**Compass Diversified Holdings** is an investment holding company, which acquires controlling interests in small-middle market businesses. Compass Diversified suffered from an accounting irregularity in its largest business.

**Edgewell Personal Care Co.** operates as a personal care company that manufactures and distributes feminine, infant, skin, pet, suncare, and shaving products. Edgewell has suffered from consistent macroeconomic headwinds including tariffs and an already stretched consumer, which have yet to show signs of relenting.

**Empire State Realty Trust Inc.** operates as a real estate investment trust, which owns, manages, operates, acquires, and repositions office and retail properties. Empire State Realty struggled due to higher New York City Real Estate taxes and other one-time expenses, as well as softer tourism demand, which compressed its operating margin.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41524.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Small Cap Value Fund Class R6** | 3.01% | 3.09% |
| **Russell 3000<sup>®</sup> Index** | 17.15% | 11.34% |
| **Russell 2000<sup>®</sup> Value Index** | 12.59% | 5.72% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$919456 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;105 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$8059 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;37% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Banc Of California, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tower Semiconductor Ltd. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Texas Capital Bancshares, Inc. | 1.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hancock Whitney Corp. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Seacoast Banking Corp. of Florida | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Gulfport Energy Corp. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Old National Bancorp | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atlantic Union Bankshares Corp. | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Commercial Metals Co. | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Atmus Filtration Technologies Inc. | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41493.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Global Leaders Fund

#### Class I / WGFIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Global Leaders Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Global Leaders Fund Class I | $97 | 0.90% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 15.20% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World IMI (net), which returned 22.06%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus its benchmark was driven by stock selection in Consumer Discretionary, Financials, and Industrials. Consumer-focused positioning detracted across Industrials and Financials underperformance was driven by an underweight to banks. Within Industrials, stock selection in the U.S., drove relative underperformance but was balanced by strong selection in aerospace and defense. Partially offsetting underperformance was strong stock selection in Health Care and Information Technology hardware.

#### TOP PERFORMANCE DETRACTORS
**Murphy USA** ("MUSA") is one of the largest convenience store chains in the U.S. and is focused on a high-volume low-price fuel offer that targets value-orientated customers. The position underperformed and was exited as the target lower-income cohort in the U.S. has reduced add-on purchases due to inflation pressures and lower oil prices have pressured margins and reduced MUSA's relative cost advantage.

**Chipotle Mexican Grill** is a global fast-casual restaurant chain that operates thousands of company-owned locations across North America and select international markets. The stock underperformed on a combination of macroeconomic factors, including margin pressure from rising food and labor costs plus a decline in restaurant traffic. The position was sold on the expectations that these pressures will remain relevant and a relatively high valuation given the downside risk.

**Ferrari** is a luxury automaker. Ferrari has underperformed on what we feel is poor communication regarding the rollout of its first fully electric vehicle and lower-than-expected sales and a conservative decrease in margin guidance as the company had experienced a boom in high-margin customization additions to its limited volume. While we view the brand as one of the strongest globally, we are monitoring management's execution.

**3i Group** is a U.K.-based private equity and infrastructure investment firm. 3i Group underperformed on its primary asset, discount retailer Action. The stock was down in the fourth quarter on weak same-store sales on consumer weakness in France. The stock de-rated meaningfully, as it was broadly held and had been a strong performer in recent years.

**Copart** operates the world's largest salvage car auction marketplace. The share price declined amid softer first-quarter results, specifically a miss in EBIT and volume softness, coupled with some concerns about future growth which led to a sale mid-year.

**BAE Systems** is the largest pure-play European defense contractor. It boasts a large and diversified portfolio that includes some of the most successful and in-demand defense programs in the world. It appreciated throughout the year on the expectations of increased defense investment, especially in Europe.

#### TOP PERFORMANCE CONTRIBUTORS
**Eli Lilly** is a leader in the market for injectable weight-loss drugs in terms of effectiveness. Eli Lilly has rallied in the fourth quarter on the removal of a key regulatory risk as the company has worked with the U.S. government to offer GLP-1 drugs directly to the consumer through a government website and through Medicare, increasing volume at prices that were higher than anticipated. Additionally, it announced positive results from a Phase III trial for a first-in-class "triple-G" Retatrutide for weight loss in overweight adults with knee osteoarthritis, and without diabetes.

**Hims & Hers** is a U.S.-based telehealth company that provides online access to licensed medical providers and prescription treatments for conditions such as hair loss, sexual health, mental health, weight loss, and skincare. The company was able to take advantage of shortages of GLP-1 drugs early in the year and compound biosimilars to Wegovy for much less than the branded drug. We had trimmed at the peak and exited after Novo terminated the distribution agreement and the U.S. government pushed for lower-cost direct access to GLP-1s.

**SK Hynix** is a South Korea–based artificial intelligence ("AI") enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41596.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Global Leaders Fund Class I** | 15.20% | 4.74% | 10.28% |
| **MSCI All Country World IMI (net)** | 22.06% | 10.75% | 11.45% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$18061 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$12 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;81% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 6.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 4.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 3.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Eli Lilly & Co. | 3.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 3.0% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41565.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41569.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Global Leaders Fund

#### Class N / WGGNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Global Leaders Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Global Leaders Fund Class N | $124 | 1.15% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 14.82% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World IMI (net), which returned 22.06%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus its benchmark was driven by stock selection in Consumer Discretionary, Financials, and Industrials. Consumer-focused positioning detracted across Industrials and Financials underperformance was driven by an underweight to banks. Within Industrials, stock selection in the U.S., drove relative underperformance but was balanced by strong selection in aerospace and defense. Partially offsetting underperformance was strong stock selection in Health Care and Information Technology hardware.

#### TOP PERFORMANCE DETRACTORS
**Murphy USA** ("MUSA") is one of the largest convenience store chains in the U.S. and is focused on a high-volume low-price fuel offer that targets value-orientated customers. The position underperformed and was exited as the target lower-income cohort in the U.S. has reduced add-on purchases due to inflation pressures and lower oil prices have pressured margins and reduced MUSA's relative cost advantage.

**Chipotle Mexican Grill** is a global fast-casual restaurant chain that operates thousands of company-owned locations across North America and select international markets. The stock underperformed on a combination of macroeconomic factors, including margin pressure from rising food and labor costs plus a decline in restaurant traffic. The position was sold on the expectations that these pressures will remain relevant and a relatively high valuation given the downside risk.

**Ferrari** is a luxury automaker. Ferrari has underperformed on what we feel is poor communication regarding the rollout of its first fully electric vehicle and lower-than-expected sales and a conservative decrease in margin guidance as the company had experienced a boom in high-margin customization additions to its limited volume. While we view the brand as one of the strongest globally, we are monitoring management's execution.

**3i Group** is a U.K.-based private equity and infrastructure investment firm. 3i Group underperformed on its primary asset, discount retailer Action. The stock was down in the fourth quarter on weak same-store sales on consumer weakness in France. The stock de-rated meaningfully, as it was broadly held and had been a strong performer in recent years.

**Copart** operates the world's largest salvage car auction marketplace. The share price declined amid softer first-quarter results, specifically a miss in EBIT and volume softness, coupled with some concerns about future growth which led to a sale mid-year.

**BAE Systems** is the largest pure-play European defense contractor. It boasts a large and diversified portfolio that includes some of the most successful and in-demand defense programs in the world. It appreciated throughout the year on the expectations of increased defense investment, especially in Europe.

#### TOP PERFORMANCE CONTRIBUTORS
**Eli Lilly** is a leader in the market for injectable weight-loss drugs in terms of effectiveness. Eli Lilly has rallied in the fourth quarter on the removal of a key regulatory risk as the company has worked with the U.S. government to offer GLP-1 drugs directly to the consumer through a government website and through Medicare, increasing volume at prices that were higher than anticipated. Additionally, it announced positive results from a Phase III trial for a first-in-class "triple-G" Retatrutide for weight loss in overweight adults with knee osteoarthritis, and without diabetes.

**Hims & Hers** is a U.S.-based telehealth company that provides online access to licensed medical providers and prescription treatments for conditions such as hair loss, sexual health, mental health, weight loss, and skincare. The company was able to take advantage of shortages of GLP-1 drugs early in the year and compound biosimilars to Wegovy for much less than the branded drug. We had trimmed at the peak and exited after Novo terminated the distribution agreement and the U.S. government pushed for lower-cost direct access to GLP-1s.

**SK Hynix** is a South Korea–based artificial intelligence ("AI") enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_41556.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Global Leaders Fund Class N** | 14.82% | 4.46% | 9.98% |
| **MSCI All Country World IMI (net)** | 22.06% | 10.75% | 11.45% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$18061 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$12 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;81% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 6.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 4.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 3.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Eli Lilly & Co. | 3.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 3.0% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41541.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41536.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Global Leaders Fund

#### Class R6 / BGGIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Global Leaders Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Global Leaders Fund Class R6 | $91 | 0.85% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 15.23% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World IMI (net), which returned 22.06%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus its benchmark was driven by stock selection in Consumer Discretionary, Financials, and Industrials. Consumer-focused positioning detracted across Industrials and Financials underperformance was driven by an underweight to banks. Within Industrials, stock selection in the U.S., drove relative underperformance but was balanced by strong selection in aerospace and defense. Partially offsetting underperformance was strong stock selection in Health Care and Information Technology hardware.

#### TOP PERFORMANCE DETRACTORS
**Murphy USA** ("MUSA") is one of the largest convenience store chains in the U.S. and is focused on a high-volume low-price fuel offer that targets value-orientated customers. The position underperformed and was exited as the target lower-income cohort in the U.S. has reduced add-on purchases due to inflation pressures and lower oil prices have pressured margins and reduced MUSA's relative cost advantage.

**Chipotle Mexican Grill** is a global fast-casual restaurant chain that operates thousands of company-owned locations across North America and select international markets. The stock underperformed on a combination of macroeconomic factors, including margin pressure from rising food and labor costs plus a decline in restaurant traffic. The position was sold on the expectations that these pressures will remain relevant and a relatively high valuation given the downside risk.

**Ferrari** is a luxury automaker. Ferrari has underperformed on what we feel is poor communication regarding the rollout of its first fully electric vehicle and lower-than-expected sales and a conservative decrease in margin guidance as the company had experienced a boom in high-margin customization additions to its limited volume. While we view the brand as one of the strongest globally, we are monitoring management's execution.

**3i Group** is a U.K.-based private equity and infrastructure investment firm. 3i Group underperformed on its primary asset, discount retailer Action. The stock was down in the fourth quarter on weak same-store sales on consumer weakness in France. The stock de-rated meaningfully, as it was broadly held and had been a strong performer in recent years.

**Copart** operates the world's largest salvage car auction marketplace. The share price declined amid softer first-quarter results, specifically a miss in EBIT and volume softness, coupled with some concerns about future growth which led to a sale mid-year.

**BAE Systems** is the largest pure-play European defense contractor. It boasts a large and diversified portfolio that includes some of the most successful and in-demand defense programs in the world. It appreciated throughout the year on the expectations of increased defense investment, especially in Europe.

#### TOP PERFORMANCE CONTRIBUTORS
**Eli Lilly** is a leader in the market for injectable weight-loss drugs in terms of effectiveness. Eli Lilly has rallied in the fourth quarter on the removal of a key regulatory risk as the company has worked with the U.S. government to offer GLP-1 drugs directly to the consumer through a government website and through Medicare, increasing volume at prices that were higher than anticipated. Additionally, it announced positive results from a Phase III trial for a first-in-class "triple-G" Retatrutide for weight loss in overweight adults with knee osteoarthritis, and without diabetes.

**Hims & Hers** is a U.S.-based telehealth company that provides online access to licensed medical providers and prescription treatments for conditions such as hair loss, sexual health, mental health, weight loss, and skincare. The company was able to take advantage of shortages of GLP-1 drugs early in the year and compound biosimilars to Wegovy for much less than the branded drug. We had trimmed at the peak and exited after Novo terminated the distribution agreement and the U.S. government pushed for lower-cost direct access to GLP-1s.

**SK Hynix** is a South Korea–based artificial intelligence ("AI") enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41628.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Global Leaders Fund Class R6** | 15.23% | 4.79% | 10.34% |
| **MSCI All Country World IMI (net)** | 22.06% | 10.75% | 11.45% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$18061 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$12 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;81% |

---

#### Graphical Representation of H ol dings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;NVIDIA Corp. | 6.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alphabet, Inc. | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Microsoft Corp. | 4.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Amazon.com, Inc. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 3.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Eli Lilly & Co. | 3.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Meta Platforms, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Mastercard, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Apple, Inc. | 3.0% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41613.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41608.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Leaders Fund

#### Class I / WILIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Leaders Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Leaders Fund Class I | $100 | 0.90% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 23.17% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. IMI (net), which returned 31.96%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus the benchmark was driven by a combination of style headwinds for quality growth and stock selection in Financials, Consumer Discretionary, and Materials. Underweights to materials and financials drove negative sector allocation. Within Financials, underperformance was driven by an underweight to European banks early in the year, and exposures in U.K.-based capital markets positions including London Stock Exchange (LSE) and 3i Group. Partially offsetting these effects was positive selection in Information Technology, and Aerospace and defense exposure within Industrials.

#### TOP PERFORMANCE DETRACTORS
**London Stock Exchange** ("LSE") is a diversified global market infrastructure and data company. The stock price has been weak for the year ended 2025 as the market believes that LSE will be negatively impacted by artificial intelligence ("AI"), like many other data and software companies. Uncertainty can put multiples at risk, but we are not convinced that LSE is indeed negatively impacted by AI given its significant moats that are wide enough to defend the business or perhaps make LSE an AI beneficiary.

**3i Group**, a U.K.-based private equity and infrastructure investment firm, underperformed on its primary asset, discount retailer Action. The stock was down in the fourth quarter on weak same-store sales on consumer weakness in France. The stock derated meaningfully as it was broadly held and had been a strong performer in recent years.

Underperformance in Financials was partially offset by exposure to **Banco Bilbao Vizcaya Argentaria** ("BBVA"). BBVA is a leading Spanish banking group with strong positions in retail and commercial banking across Spain, Mexico, and South America. The company benefits from structural growth in emerging markets and has demonstrated disciplined risk management and solid capital ratios. The stock appreciated on the tailwind of a steepening yield curve but outperformed many of its peers through exceptional fundamentals, including record profits driven by its digital transformation efforts and the implementation of a substantial share buyback program.

**BYD** is the largest EV manufacturer in the world as BYD surpassed Tesla's global sales. The stock appreciated in the first quarter as it introduced a new technology offering with ultra-fast charging capabilities that enable 250 miles of range with just a five-minute charge, but disappointed and was sold as Chinese consumer demand weakened and domestic competition drove margin dilutive pricing cuts that outweighed volume gains from international expansion.

**Ferrari** is a luxury automaker. Ferrari has underperformed on what we believe is poor communication regarding the rollout of its first fully electric vehicle and lower-than-expected sales, and a conservative decrease in margin guidance as the company had experienced a boom in high-margin customization additions to its limited volume. While we view the brand as one of the strongest globally, we are monitoring management's execution.

**Symrise** is a German specialty chemicals company that develops and produces flavors, fragrances, cosmetic ingredients, and nutritional solutions used in food, beverages, personal care, and other consumer products. It supplies small, in both amount and cost, ingredients that provide crucial functionality to end-products but only make up a small portion of the input costs. The stock disappointed on slower organic growth and outlook on weak demand from consumers including those impacted by tariffs on its customers' final products.

This was partially offset by exposure to **Heidelberg Materials**. Heidelberg Materials is a German cement, aggregates, and ready-mix/asphalt supplier to the construction industry across infrastructure, commercial, and residential applications. Europe, and Germany in particular, are reacting to heightened tensions with the U.S. on defense and trade through defense and infrastructure spending after underinvesting for decades. Heidelberg is benefiting from increased infrastructure spending as Europe's largest cement producer and aggregates supplier and, in our view, there is additional upside to current earnings estimates.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued demand for AI and tailwinds for Korean equities following the presidential election in early June that brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Thales** is among the world's leading providers of critical secure communications systems, with main applications in the defense, aerospace, telecommunication, and banking industries. After a successful run in 2025, we exited the position in favor of better growth opportunities in the aerospace thematic.

**BAE Systems** is the largest pure-play European defense contractor with exposure to some of the largest defense markets in the world. It boasts a large and diversified portfolio that includes some of the most successful and in-demand defense programs in the world. Both appreciated throughout the year on the expectations of increased defense investment, especially in Europe, which we believe will continue long past current conflicts as Europe looks to build its capabilities to confront a more aggressive Russia without the implicit backing of the U.S.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41700.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Leaders Fund Class I** | 23.17% | 1.76% | 7.69% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1095321 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;57 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$8615 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;91% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 5.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon Hai Precision Industry Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Sandoz Group AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Banco Bilbao Vizcaya Argentaria S.A. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Heidelberg Materials AG | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Barclays PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.2% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41685.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41680.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Leaders Fund

#### Class N / WILNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Leaders Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Leaders Fund Class N | $128 | 1.15% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 22.88% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. IMI (net), which returned 31.96%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus the benchmark was driven by a combination of style headwinds for quality growth and stock selection in Financials, Consumer Discretionary, and Materials. Underweights to materials and financials drove negative sector allocation. Within Financials, underperformance was driven by an underweight to European banks early in the year, and exposures in U.K.-based capital markets positions including London Stock Exchange (LSE) and 3i Group. Partially offsetting these effects was positive selection in Information Technology, and Aerospace and defense exposure within Industrials.

#### TOP PERFORMANCE DETRACTORS
**London Stock Exchange** ("LSE") is a diversified global market infrastructure and data company. The stock price has been weak for the year ended 2025 as the market believes that LSE will be negatively impacted by artificial intelligence ("AI"), like many other data and software companies. Uncertainty can put multiples at risk, but we are not convinced that LSE is indeed negatively impacted by AI given its significant moats that are wide enough to defend the business or perhaps make LSE an AI beneficiary.

**3i Group**, a U.K.-based private equity and infrastructure investment firm, underperformed on its primary asset, discount retailer Action. The stock was down in the fourth quarter on weak same-store sales on consumer weakness in France. The stock derated meaningfully as it was broadly held and had been a strong performer in recent years.

Underperformance in Financials was partially offset by exposure to **Banco Bilbao Vizcaya Argentaria** ("BBVA"). BBVA is a leading Spanish banking group with strong positions in retail and commercial banking across Spain, Mexico, and South America. The company benefits from structural growth in emerging markets and has demonstrated disciplined risk management and solid capital ratios. The stock appreciated on the tailwind of a steepening yield curve but outperformed many of its peers through exceptional fundamentals, including record profits driven by its digital transformation efforts and the implementation of a substantial share buyback program.

**BYD** is the largest EV manufacturer in the world as BYD surpassed Tesla's global sales. The stock appreciated in the first quarter as it introduced a new technology offering with ultra-fast charging capabilities that enable 250 miles of range with just a five-minute charge, but disappointed and was sold as Chinese consumer demand weakened and domestic competition drove margin dilutive pricing cuts that outweighed volume gains from international expansion.

**Ferrari** is a luxury automaker. Ferrari has underperformed on what we believe is poor communication regarding the rollout of its first fully electric vehicle and lower-than-expected sales, and a conservative decrease in margin guidance as the company had experienced a boom in high-margin customization additions to its limited volume. While we view the brand as one of the strongest globally, we are monitoring management's execution.

**Symrise** is a German specialty chemicals company that develops and produces flavors, fragrances, cosmetic ingredients, and nutritional solutions used in food, beverages, personal care, and other consumer products. It supplies small, in both amount and cost, ingredients that provide crucial functionality to end-products but only make up a small portion of the input costs. The stock disappointed on slower organic growth and outlook on weak demand from consumers including those impacted by tariffs on its customers' final products.

This was partially offset by exposure to **Heidelberg Materials**. Heidelberg Materials is a German cement, aggregates, and ready-mix/asphalt supplier to the construction industry across infrastructure, commercial, and residential applications. Europe, and Germany in particular, are reacting to heightened tensions with the U.S. on defense and trade through defense and infrastructure spending after underinvesting for decades. Heidelberg is benefiting from increased infrastructure spending as Europe's largest cement producer and aggregates supplier and, in our view, there is additional upside to current earnings estimates.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued demand for AI and tailwinds for Korean equities following the presidential election in early June that brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Thales** is among the world's leading providers of critical secure communications systems, with main applications in the defense, aerospace, telecommunication, and banking industries. After a successful run in 2025, we exited the position in favor of better growth opportunities in the aerospace thematic.

**BAE Systems** is the largest pure-play European defense contractor with exposure to some of the largest defense markets in the world. It boasts a large and diversified portfolio that includes some of the most successful and in-demand defense programs in the world. Both appreciated throughout the year on the expectations of increased defense investment, especially in Europe, which we believe will continue long past current conflicts as Europe looks to build its capabilities to confront a more aggressive Russia without the implicit backing of the U.S.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_41669.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Leaders Fund Class N** | 22.88% | 1.51% | 7.42% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1095321 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;57 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$8615 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;91% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 5.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon Hai Precision Industry Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Sandoz Group AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Banco Bilbao Vizcaya Argentaria S.A. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Heidelberg Materials AG | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Barclays PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.2% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41637.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41642.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Leaders Fund

#### Class R6 / WILJX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Leaders Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Leaders Fund Class R6 | $95 | 0.85% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 23.27% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. IMI (net), which returned 31.96%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus the benchmark was driven by a combination of style headwinds for quality growth and stock selection in Financials, Consumer Discretionary, and Materials. Underweights to materials and financials drove negative sector allocation. Within Financials, underperformance was driven by an underweight to European banks early in the year, and exposures in U.K.-based capital markets positions including London Stock Exchange (LSE) and 3i Group. Partially offsetting these effects was positive selection in Information Technology, and Aerospace and defense exposure within Industrials.

#### TOP PERFORMANCE DETRACTORS
**London Stock Exchange** ("LSE") is a diversified global market infrastructure and data company. The stock price has been weak for the year ended 2025 as the market believes that LSE will be negatively impacted by artificial intelligence ("AI"), like many other data and software companies. Uncertainty can put multiples at risk, but we are not convinced that LSE is indeed negatively impacted by AI given its significant moats that are wide enough to defend the business or perhaps make LSE an AI beneficiary.

**3i Group**, a U.K.-based private equity and infrastructure investment firm, underperformed on its primary asset, discount retailer Action. The stock was down in the fourth quarter on weak same-store sales on consumer weakness in France. The stock derated meaningfully as it was broadly held and had been a strong performer in recent years.

Underperformance in Financials was partially offset by exposure to **Banco Bilbao Vizcaya Argentaria** ("BBVA"). BBVA is a leading Spanish banking group with strong positions in retail and commercial banking across Spain, Mexico, and South America. The company benefits from structural growth in emerging markets and has demonstrated disciplined risk management and solid capital ratios. The stock appreciated on the tailwind of a steepening yield curve but outperformed many of its peers through exceptional fundamentals, including record profits driven by its digital transformation efforts and the implementation of a substantial share buyback program.

**BYD** is the largest EV manufacturer in the world as BYD surpassed Tesla's global sales. The stock appreciated in the first quarter as it introduced a new technology offering with ultra-fast charging capabilities that enable 250 miles of range with just a five-minute charge, but disappointed and was sold as Chinese consumer demand weakened and domestic competition drove margin dilutive pricing cuts that outweighed volume gains from international expansion.

**Ferrari** is a luxury automaker. Ferrari has underperformed on what we believe is poor communication regarding the rollout of its first fully electric vehicle and lower-than-expected sales, and a conservative decrease in margin guidance as the company had experienced a boom in high-margin customization additions to its limited volume. While we view the brand as one of the strongest globally, we are monitoring management's execution.

**Symrise** is a German specialty chemicals company that develops and produces flavors, fragrances, cosmetic ingredients, and nutritional solutions used in food, beverages, personal care, and other consumer products. It supplies small, in both amount and cost, ingredients that provide crucial functionality to end-products but only make up a small portion of the input costs. The stock disappointed on slower organic growth and outlook on weak demand from consumers including those impacted by tariffs on its customers' final products.

This was partially offset by exposure to **Heidelberg Materials**. Heidelberg Materials is a German cement, aggregates, and ready-mix/asphalt supplier to the construction industry across infrastructure, commercial, and residential applications. Europe, and Germany in particular, are reacting to heightened tensions with the U.S. on defense and trade through defense and infrastructure spending after underinvesting for decades. Heidelberg is benefiting from increased infrastructure spending as Europe's largest cement producer and aggregates supplier and, in our view, there is additional upside to current earnings estimates.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued demand for AI and tailwinds for Korean equities following the presidential election in early June that brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Thales** is among the world's leading providers of critical secure communications systems, with main applications in the defense, aerospace, telecommunication, and banking industries. After a successful run in 2025, we exited the position in favor of better growth opportunities in the aerospace thematic.

**BAE Systems** is the largest pure-play European defense contractor with exposure to some of the largest defense markets in the world. It boasts a large and diversified portfolio that includes some of the most successful and in-demand defense programs in the world. Both appreciated throughout the year on the expectations of increased defense investment, especially in Europe, which we believe will continue long past current conflicts as Europe looks to build its capabilities to confront a more aggressive Russia without the implicit backing of the U.S.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41739.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Leaders Fund Class R6** | 23.27% | 1.81% | 7.76% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1095321 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;57 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$8615 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;91% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 5.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon Hai Precision Industry Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Sandoz Group AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Banco Bilbao Vizcaya Argentaria S.A. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Heidelberg Materials AG | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Barclays PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.2% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41709.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41714.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Growth Fund

#### Class I / BIGIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### This report describes changes to the Fund that occurred during the reporting period.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Growth Fund Class I | $101 | 0.93% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 18.01% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. IMI (net), which returned 31.96%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus the benchmark was driven by pronounced style headwinds in which low valuation outperformed, and high quality underperformed to a significant degree. This headwind resulted in weaker selection across most sectors, particularly within Financials and Industrials. The strategy's sector allocation was slightly negative as an underweight to Materials and an overweight to Consumer Discretionary offset the positive effects of an underweight to Consumer Staples and an overweight to Industrials.

#### TOP PERFORMANCE DETRACTORS
**London Stock Exchange** ("LSE") is a diversified global market infrastructure and data company. The stock price has been weak in 2025 as the market believes that LSE will be negatively impacted by artificial intelligence ("AI"), like many other data and software companies. Uncertainty can put multiples at risk, but we are not convinced that LSE is indeed negatively impacted by AI given its significant moats that are wide enough to defend the business or perhaps make LSE an AI beneficiary.

**Bank Central Asia** declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns about the new administration's policy direction. In our view, fiscal 2025 guidance remains conservative, and as sentiment improves, we see positive catalysts for the stock to re-rate higher.

**Cie de Saint-Gobain** is a French building materials company with a global footprint and market-leading positions across multiple verticals. The company has undergone a significant transformation from a collection of largely commoditized businesses that were partially unrelated to a more structured approach, becoming a broader construction solutions provider. The share price softened modestly in the fourth quarter amid weaker third-quarter results, with top-line growth slightly lower than expectations.

#### TOP PERFORMANCE CONTRIBUTORS
**Thales** is among the world's leading providers of critical secure communications systems, with main applications in the defense, aerospace, telecommunication, and banking industries. After a successful run in 2025, we exited the position in favor of better growth opportunities in the aerospace thematic.

**SK Hynix** is a South Korea-based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued demand for AI and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41812.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Growth Fund Class I** | 18.01% | 1.73% | 6.91% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1121225 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;171 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$9789 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;77% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;AstraZeneca PLC | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon Hai Precision Industry Co., Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;UniCredit S.p.A. | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Lonza Group AG | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41782.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41786.jpg)

#### Material Fund Changes
Effective May 1, 2025, the management fee paid to the Fund's adviser was reduced to 0.85% of the first $10 billion of the Fund's average daily net assets; plus 0.825% of the next $5 billion of the Fund's average daily net assets; plus 0.80% of the Fund's average daily net assets over $15 billion.

Effective May 1, 2025, the Fund's adviser has entered into a contractual agreement with the Fund to waive fees and/or reimburse expenses in order to limit the Fund's operating expenses (excluding interest expenses, taxes, brokerage commissions, acquired fund fees and expenses, dividend and interest expenses on short sales, other investment-related costs and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of the Fund's business) to 1.15%, 0.90% and 0.85% of average daily net assets for Class N, Class I and Class R6 shares, respectively, until April 30, 2026.

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Growth Fund

#### Class N / WBIGX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### This report describes changes to the Fund that occurred during the reporting period.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Growth Fund Class N | $128 | 1.18% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 17.74% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. IMI (net), which returned 31.96%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus the benchmark was driven by pronounced style headwinds in which low valuation outperformed, and high quality underperformed to a significant degree. This headwind resulted in weaker selection across most sectors, particularly within Financials and Industrials. The strategy's sector allocation was slightly negative as an underweight to Materials and an overweight to Consumer Discretionary offset the positive effects of an underweight to Consumer Staples and an overweight to Industrials.

#### TOP PERFORMANCE DETRACTORS
**London Stock Exchange** ("LSE") is a diversified global market infrastructure and data company. The stock price has been weak in 2025 as the market believes that LSE will be negatively impacted by artificial intelligence ("AI"), like many other data and software companies. Uncertainty can put multiples at risk, but we are not convinced that LSE is indeed negatively impacted by AI given its significant moats that are wide enough to defend the business or perhaps make LSE an AI beneficiary.

**Bank Central Asia** declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns about the new administration's policy direction. In our view, fiscal 2025 guidance remains conservative, and as sentiment improves, we see positive catalysts for the stock to re-rate higher.

**Cie de Saint-Gobain** is a French building materials company with a global footprint and market-leading positions across multiple verticals. The company has undergone a significant transformation from a collection of largely commoditized businesses that were partially unrelated to a more structured approach, becoming a broader construction solutions provider. The share price softened modestly in the fourth quarter amid weaker third-quarter results, with top-line growth slightly lower than expectations.

#### TOP PERFORMANCE CONTRIBUTORS
**Thales** is among the world's leading providers of critical secure communications systems, with main applications in the defense, aerospace, telecommunication, and banking industries. After a successful run in 2025, we exited the position in favor of better growth opportunities in the aerospace thematic.

**SK Hynix** is a South Korea-based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued demand for AI and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_41772.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Growth Fund Class N** | 17.74% | 1.46% | 6.61% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1121225 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;171 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$9789 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;77% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;AstraZeneca PLC | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon Hai Precision Industry Co., Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;UniCredit S.p.A. | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Lonza Group AG | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41757.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41752.jpg)

#### Material Fund Changes
Effective May 1, 2025, the management fee paid to the Fund's adviser was reduced to 0.85% of the first $10 billion of the Fund's average daily net assets; plus 0.825% of the next $5 billion of the Fund's average daily net assets; plus 0.80% of the Fund's average daily net assets over $15 billion.

Effective May 1, 2025, the Fund's adviser has entered into a contractual agreement with the Fund to waive fees and/or reimburse expenses in order to limit the Fund's operating expenses (excluding interest expenses, taxes, brokerage commissions, acquired fund fees and expenses, dividend and interest expenses on short sales, other investment-related costs and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of the Fund's business) to 1.15%, 0.90% and 0.85% of average daily net assets for Class N, Class I and Class R6 shares, respectively, until April 30, 2026.

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Growth Fund

#### Class R6 / WBIRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### This report describes changes to the Fund that occurred during the reporting period.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Growth Fund Class R6 | $96 | 0.88% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 18.07% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. IMI (net), which returned 31.96%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus the benchmark was driven by pronounced style headwinds in which low valuation outperformed, and high quality underperformed to a significant degree. This headwind resulted in weaker selection across most sectors, particularly within Financials and Industrials. The strategy's sector allocation was slightly negative as an underweight to Materials and an overweight to Consumer Discretionary offset the positive effects of an underweight to Consumer Staples and an overweight to Industrials.

#### TOP PERFORMANCE DETRACTORS
**London Stock Exchange** ("LSE") is a diversified global market infrastructure and data company. The stock price has been weak in 2025 as the market believes that LSE will be negatively impacted by artificial intelligence ("AI"), like many other data and software companies. Uncertainty can put multiples at risk, but we are not convinced that LSE is indeed negatively impacted by AI given its significant moats that are wide enough to defend the business or perhaps make LSE an AI beneficiary.

**Bank Central Asia** declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns about the new administration's policy direction. In our view, fiscal 2025 guidance remains conservative, and as sentiment improves, we see positive catalysts for the stock to re-rate higher.

**Cie de Saint-Gobain** is a French building materials company with a global footprint and market-leading positions across multiple verticals. The company has undergone a significant transformation from a collection of largely commoditized businesses that were partially unrelated to a more structured approach, becoming a broader construction solutions provider. The share price softened modestly in the fourth quarter amid weaker third-quarter results, with top-line growth slightly lower than expectations.

#### TOP PERFORMANCE CONTRIBUTORS
**Thales** is among the world's leading providers of critical secure communications systems, with main applications in the defense, aerospace, telecommunication, and banking industries. After a successful run in 2025, we exited the position in favor of better growth opportunities in the aerospace thematic.

**SK Hynix** is a South Korea-based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued demand for AI and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41843.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **Since Inception** |
| **International Growth Fund Class R6** | 18.07% | 1.78% | 7.43% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.60% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1121225 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;171 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$9789 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;77% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;AstraZeneca PLC | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon Hai Precision Industry Co., Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;UniCredit S.p.A. | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Lonza Group AG | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41829.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41824.jpg)

#### Material Fund Changes
Effective May 1, 2025, the management fee paid to the Fund's adviser was reduced to 0.85% of the first $10 billion of the Fund's average daily net assets; plus 0.825% of the next $5 billion of the Fund's average daily net assets; plus 0.80% of the Fund's average daily net assets over $15 billion.

Effective May 1, 2025, the Fund's adviser has entered into a contractual agreement with the Fund to waive fees and/or reimburse expenses in order to limit the Fund's operating expenses (excluding interest expenses, taxes, brokerage commissions, acquired fund fees and expenses, dividend and interest expenses on short sales, other investment-related costs and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of the Fund's business) to 1.15%, 0.90% and 0.85% of average daily net assets for Class N, Class I and Class R6 shares, respectively, until April 30, 2026.

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Institutional International Growth Fund

#### Institutional Class / WBIIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Institutional International Growth Fund Institutional (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### This report describes changes to the Fund that occurred during the reporting period.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Institutional International Growth Fund | $96 | 0.88% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 18.05% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. IMI (net), which returned 31.96%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus the benchmark was driven by pronounced style headwinds in which low valuation outperformed, and high quality underperformed to a significant degree. This headwind resulted in weaker selection across most sectors, particularly within Financials and Industrials. The strategy's sector allocation was slightly negative as an underweight to Materials and an overweight to Consumer Discretionary offset the positive effects of an underweight to Consumer Staples and an overweight to Industrials.

#### TOP PERFORMANCE DETRACTORS
**London Stock Exchange** ("LSE") is a diversified global market infrastructure and data company. The stock price has been weak in 2025 as the market believes that LSE will be negatively impacted by artificial intelligence ("AI"), like many other data and software companies. Uncertainty can put multiples at risk, but we are not convinced that LSE is indeed negatively impacted by AI given its significant moats that are wide enough to defend the business or perhaps make LSE an AI beneficiary.

**Bank Central Asia** declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns about the new administration's policy direction. In our view, fiscal 2025 guidance remains conservative, and as sentiment improves, we see positive catalysts for the stock to re-rate higher.

**Cie de Saint-Gobain** is a French building materials company with a global footprint and market-leading positions across multiple verticals. The company has undergone a significant transformation from a collection of largely commoditized businesses that were partially unrelated to a more structured approach, becoming a broader construction solutions provider. The share price softened modestly in the fourth quarter amid weaker third-quarter results, with top-line growth slightly lower than expectations.

#### TOP PERFORMANCE CONTRIBUTORS
**Thales** is among the world's leading providers of critical secure communications systems, with main applications in the defense, aerospace, telecommunication, and banking industries. After a successful run in 2025, we exited the position in favor of better growth opportunities in the aerospace thematic.

**SK Hynix** is a South Korea-based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued demand for AI and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $5,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $5,000,000
![Fund Performance - Growth of 10K](chartimages_41884.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Institutional International Growth Fund** | 18.05% | 1.78% | 7.03% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$834540 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;171 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$7644 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;79% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 4.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;AstraZeneca PLC | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon Hai Precision Industry Co., Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;UniCredit S.p.A. | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Lonza Group AG | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41853.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41858.jpg)

#### Material Fund Changes
Effective May 1, 2025, the management fee paid to the Fund's adviser was reduced to 0.85% of the first $10 billion of the Fund's average daily net assets; plus 0.825% of the next $5 billion of the Fund's average daily net assets; plus 0.80% of the Fund's average daily net assets over $15 billion.

Effective May 1, 2025, the Fund's adviser has entered into a contractual agreement with the Fund to waive fees and/or reimburse expenses in order to limit the Fund's operating expenses (excluding interest expenses, taxes, brokerage commissions, acquired fund fees and expenses, dividend and interest expenses on short sales, other investment-related costs and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of the Fund's business) to 0.85% of average daily net assets for shares until April 30, 2026.

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Small Cap Growth Fund

#### Class I / WISIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Small Cap Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### This report describes changes to the Fund that occurred during the reporting period.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Small Cap Growth Fund Class I | $118 | 1.10% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 15.30% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. Small Cap Index (net), which returned 29.26% and underperformed the MSCI All Country World ex-U.S. IMI (net), a broad measure of market performance, which returned 31.96%.

The Fund's underperformance versus its benchmark primarily occurred in the second half of the year as the market shifted to a pronounced risk-on environment, with lower quality and speculative segments of the market sharply outperforming the broader market. This valuation headwind stands out relative to history, even surpassing calendar 2022. This style headwind resulted in weaker selection across most sectors in 2025, most notably within communication services and financials. An underweight allocation to materials, specifically metals and mining, was also a notable detractor as the industry was up in 2025. with an end weight of 7.2% of the index (currently the largest industry of MSCI ACWI ex US Small Cap Index).

#### TOP PERFORMANCE DETRACTORS
**Trustpilot Group** is a global online review platform where consumers can share and read reviews about businesses, products, and services. The position had outperformed throughout the last year on a series of earnings announcements that exceeded market expectations due to strong execution, as recent product launches and price increases had been well received. Share prices fell in the period despite continued strong results on the market reaction to accounting adjustments in the capitalization of software development costs, share-based compensation, and the exhaustion of tax credits for prior losses as the company is now profitable.

**Hemnet Group** is Sweden's No.1 online real estate marketplace. The stock underperformed in the period as fundamental results missed market expectations on lower volumes and longer listing times. We exited the position in the fourth quarter.

**Kfin Technologies** operates in a duopoly in a structurally growing business as one of the two Indian registrar and transfer agents available to mutual funds and large corporates. Kfin Technologies also provides SaaS-based transaction management, channel management, compliance solutions, and various other digital services to asset managers across segments. While Kfin Technologies continues to deliver strong fundamental results, the stock underperformed with the broader Indian market on a macroeconomic slowdown.

#### TOP PERFORMANCE CONTRIBUTORS
**Elite Material** manufactures copper-clad laminates (CCLs) that serve as the base material of printed circuit boards (PCBs), where electronic components are mounted and connected. Products include traditional CCL, prepreg, and multilayer laminates —approximately 65% of revenue is generated from products using "green" (i.e., halogen-free) resins. The share price advanced on solid second quarter results as an improved product mix with more artificial intelligence servers offset the impact from the stronger New Taiwan dollar.

**TechnoPro** is one of Japan's largest staffing and consulting firms, providing a focus on IT engineering solutions. The stock rallied on news of a takeover from asset manager Blackstone which would take TechnoPro private. We exited the position accordingly.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_41956.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Small Cap Growth Fund Class I** | 15.30% | -0.74% | 4.83% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |
| **MSCI All Country World ex-U.S. Small Cap Index (net)** | 29.26% | 6.91% | 8.13% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$130252 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;130 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1256 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;69% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Azimut Holding SpA | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bizlink Holding Inc. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;OBIC Business Consultants Co. Ltd. | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;flatexDEGIRO AG | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon. Precision, Inc | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Dassault Aviation SA | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Brunello Cucinelli SpA | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bufab AB | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Definity Financial Corp. | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41925.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41930.jpg)

#### Material Fund Changes
Effective March 21, 2025, the Fund's adviser changed its definition of a small cap company to a company that has a float adjusted market capitalization at the time of purchase no larger than the greater of $5 billion or the largest capitalized company included in the MSCI ACWI ex US Small Cap Index (net).

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Small Cap Growth Fund

#### Class N / WISNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Small Cap Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### This report describes changes to the Fund that occurred during the reporting period.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Small Cap Growth Fund Class N | $145 | 1.35% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 14.98% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. Small Cap Index (net), which returned 29.26% and underperformed the MSCI All Country World ex-U.S. IMI (net), a broad measure of market performance, which returned 31.96%.

The Fund's underperformance versus its benchmark primarily occurred in the second half of the year as the market shifted to a pronounced risk-on environment, with lower quality and speculative segments of the market sharply outperforming the broader market. This valuation headwind stands out relative to history, even surpassing calendar 2022. This style headwind resulted in weaker selection across most sectors in 2025, most notably within communication services and financials. An underweight allocation to materials, specifically metals and mining, was also a notable detractor as the industry was up in 2025. with an end weight of 7.2% of the index (currently the largest industry of MSCI ACWI ex US Small Cap Index).

#### TOP PERFORMANCE DETRACTORS
**Trustpilot Group** is a global online review platform where consumers can share and read reviews about businesses, products, and services. The position had outperformed throughout the last year on a series of earnings announcements that exceeded market expectations due to strong execution, as recent product launches and price increases had been well received. Share prices fell in the period despite continued strong results on the market reaction to accounting adjustments in the capitalization of software development costs, share-based compensation, and the exhaustion of tax credits for prior losses as the company is now profitable.

**Hemnet Group** is Sweden's No.1 online real estate marketplace. The stock underperformed in the period as fundamental results missed market expectations on lower volumes and longer listing times. We exited the position in the fourth quarter.

**Kfin Technologies** operates in a duopoly in a structurally growing business as one of the two Indian registrar and transfer agents available to mutual funds and large corporates. Kfin Technologies also provides SaaS-based transaction management, channel management, compliance solutions, and various other digital services to asset managers across segments. While Kfin Technologies continues to deliver strong fundamental results, the stock underperformed with the broader Indian market on a macroeconomic slowdown.

#### TOP PERFORMANCE CONTRIBUTORS
**Elite Material** manufactures copper-clad laminates (CCLs) that serve as the base material of printed circuit boards (PCBs), where electronic components are mounted and connected. Products include traditional CCL, prepreg, and multilayer laminates —approximately 65% of revenue is generated from products using "green" (i.e., halogen-free) resins. The share price advanced on solid second quarter results as an improved product mix with more artificial intelligence servers offset the impact from the stronger New Taiwan dollar.

**TechnoPro** is one of Japan's largest staffing and consulting firms, providing a focus on IT engineering solutions. The stock rallied on news of a takeover from asset manager Blackstone which would take TechnoPro private. We exited the position accordingly.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_41916.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Small Cap Growth Fund Class N** | 14.98% | -1.00% | 4.54% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |
| **MSCI All Country World ex-U.S. Small Cap Index (net)** | 29.26% | 6.91% | 8.13% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$130252 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;130 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1256 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;69% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Azimut Holding SpA | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bizlink Holding Inc. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;OBIC Business Consultants Co. Ltd. | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;flatexDEGIRO AG | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon. Precision, Inc | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Dassault Aviation SA | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Brunello Cucinelli SpA | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bufab AB | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Definity Financial Corp. | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41900.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41895.jpg)

#### Material Fund Changes
Effective March 21, 2025, the Fund's adviser changed its definition of a small cap company to a company that has a float adjusted market capitalization at the time of purchase no larger than the greater of $5 billion or the largest capitalized company included in the MSCI ACWI ex US Small Cap Index (net).

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair International Small Cap Growth Fund

#### Class R6 / WIISX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair International Small Cap Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### This report describes changes to the Fund that occurred during the reporting period.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| International Small Cap Growth Fund Class R6 | $113 | 1.05% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 15.42% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI All Country World ex-U.S. Small Cap Index (net), which returned 29.26% and underperformed the MSCI All Country World ex-U.S. IMI (net), a broad measure of market performance, which returned 31.96%.

The Fund's underperformance versus its benchmark primarily occurred in the second half of the year as the market shifted to a pronounced risk-on environment, with lower quality and speculative segments of the market sharply outperforming the broader market. This valuation headwind stands out relative to history, even surpassing calendar 2022. This style headwind resulted in weaker selection across most sectors in 2025, most notably within communication services and financials. An underweight allocation to materials, specifically metals and mining, was also a notable detractor as the industry was up in 2025. with an end weight of 7.2% of the index (currently the largest industry of MSCI ACWI ex US Small Cap Index).

#### TOP PERFORMANCE DETRACTORS
**Trustpilot Group** is a global online review platform where consumers can share and read reviews about businesses, products, and services. The position had outperformed throughout the last year on a series of earnings announcements that exceeded market expectations due to strong execution, as recent product launches and price increases had been well received. Share prices fell in the period despite continued strong results on the market reaction to accounting adjustments in the capitalization of software development costs, share-based compensation, and the exhaustion of tax credits for prior losses as the company is now profitable.

**Hemnet Group** is Sweden's No.1 online real estate marketplace. The stock underperformed in the period as fundamental results missed market expectations on lower volumes and longer listing times. We exited the position in the fourth quarter.

**Kfin Technologies** operates in a duopoly in a structurally growing business as one of the two Indian registrar and transfer agents available to mutual funds and large corporates. Kfin Technologies also provides SaaS-based transaction management, channel management, compliance solutions, and various other digital services to asset managers across segments. While Kfin Technologies continues to deliver strong fundamental results, the stock underperformed with the broader Indian market on a macroeconomic slowdown.

#### TOP PERFORMANCE CONTRIBUTORS
**Elite Material** manufactures copper-clad laminates (CCLs) that serve as the base material of printed circuit boards (PCBs), where electronic components are mounted and connected. Products include traditional CCL, prepreg, and multilayer laminates —approximately 65% of revenue is generated from products using "green" (i.e., halogen-free) resins. The share price advanced on solid second quarter results as an improved product mix with more artificial intelligence servers offset the impact from the stronger New Taiwan dollar.

**TechnoPro** is one of Japan's largest staffing and consulting firms, providing a focus on IT engineering solutions. The stock rallied on news of a takeover from asset manager Blackstone which would take TechnoPro private. We exited the position accordingly.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_41988.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **International Small Cap Growth Fund Class R6** | 15.42% | -0.67% | 4.92% |
| **MSCI All Country World ex-U.S. IMI (net)** | 31.96% | 7.77% | 8.37% |
| **MSCI All Country World ex-U.S. Small Cap Index (net)** | 29.26% | 6.91% | 8.13% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$130252 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;130 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1256 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;69% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Azimut Holding SpA | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bizlink Holding Inc. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;OBIC Business Consultants Co. Ltd. | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;flatexDEGIRO AG | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon. Precision, Inc | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Dassault Aviation SA | 1.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Brunello Cucinelli SpA | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bufab AB | 1.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Definity Financial Corp. | 1.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41973.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_41968.jpg)

#### Material Fund Changes
Effective March 21, 2025, the Fund's adviser changed its definition of a small cap company to a company that has a float adjusted market capitalization at the time of purchase no larger than the greater of $5 billion or the largest capitalized company included in the MSCI ACWI ex US Small Cap Index (net).

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Leaders Fund

#### Class I / WBELX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Leaders Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Leaders Fund Class I | $112 | 0.99% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 26.43% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets Index (net), which returned 33.57%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus its benchmark during the year was driven by a combination of stock selection in Consumer Discretionary and Industrials, and sector allocation effects. Weak stock selection within Consumer Discretionary and Industrials were the primary drivers of underperformance. From a sector allocation perspective, an underweight to Materials and an overweight to Information Technology also weighed on relative returns.

#### TOP PERFORMANCE DETRACTORS
**Trip.com** is China's leading online travel agency, with a dominant market share. While fundamental performance continues to benefit from the structural growth in Chinese consumers' travel spending, the stock price declined earlier in the year after management reduced expected margins as it is looking to expand the platform internationally. More recently, fluctuations in market perception of artificial intelligence ("AI") disruption risk are expected to weigh on near-term multiples, creating stock overhang.

**Meituan** is the leading Chinese online platform for food delivery and local services, and it also offers hotel and travel booking services. The company underperformed in 2025, primarily due to intensifying competitive pressure, most notably a price war initiated by JD.com, which drove margin compression and weighed on earnings expectations. Broader weakness across the Chinese consumer further exacerbated the stock's decline, as did rising competitive threats. We exited the position on expectations for further downward pressure.

**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. The stock detracted in the fourth quarter after the company delivered weaker-than-expected margins due to losses in quick commerce and investments in cloud.

**Voltronic Power Technology** is a white-label, outsourced designer and manufacturer of uninterrupted power supply units and power inverters used in applications including solar, energy storage, and electrical vehicle chargers. The stock underperformed during the year following rising competition, particularly from China, and weakening end-market demand. The position was exited on near-term weakness.

**WEG** is a Brazilian manufacturer of industrial machinery. The company provides products including electric motors, power and distribution transformers, large motors, direct current motors, generators, drives, programmable controllers, electric panels, and electrical components. The stock's underperformance was in part driven by a challenging geopolitical backdrop coupled with negative currency effects. Margin compression also weighed on profitability, largely due to higher raw material costs. The position was exited during the period.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Eurobank Ergasias Services** is one of four systemic Greek banks that benefit from above-average growth in the eurozone. It offers retail and commercial banking, asset management, investment banking, and insurance services in Greece. It is differentiated from other Greek banks through its M&A-focused expansion strategy outside of Greece, which is focused on Cyprus and Bulgaria. The bank benefits from scale and has a track record of strong capital allocation leading to above-average growth and returns.

**Delta Electronics** delivered robust returns as demand for AI data center infrastructure, power electronics, and liquid cooling systems accelerated, with disciplined margin execution further reinforcing investor confidence. The position was exited on valuation concerns following a period of strong performance.

**ASPEED Technology** contributed the most amid strong performance, as the company benefited from accelerating demand for AI server infrastructure and continued strength in enterprise cloud spending.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_42059.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Leaders Fund Class I** | 26.43% | -0.51% | 6.64% |
| **MSCI Emerging Markets Index (net)** | 33.57% | 4.20% | 8.42% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$95763 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;51 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$990 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;79% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 13.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 6.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 3.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;NU Holdings Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;NetEase, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Contemporary Amperex Technology Co. Ltd. | 2.4% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42045.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42040.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Leaders Fund

#### Class N / WELNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Leaders Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Leaders Fund Class N | $140 | 1.24% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 26.05% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets Index (net), which returned 33.57%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus its benchmark during the year was driven by a combination of stock selection in Consumer Discretionary and Industrials, and sector allocation effects. Weak stock selection within Consumer Discretionary and Industrials were the primary drivers of underperformance. From a sector allocation perspective, an underweight to Materials and an overweight to Information Technology also weighed on relative returns.

#### TOP PERFORMANCE DETRACTORS
**Trip.com** is China's leading online travel agency, with a dominant market share. While fundamental performance continues to benefit from the structural growth in Chinese consumers' travel spending, the stock price declined earlier in the year after management reduced expected margins as it is looking to expand the platform internationally. More recently, fluctuations in market perception of artificial intelligence ("AI") disruption risk are expected to weigh on near-term multiples, creating stock overhang.

**Meituan** is the leading Chinese online platform for food delivery and local services, and it also offers hotel and travel booking services. The company underperformed in 2025, primarily due to intensifying competitive pressure, most notably a price war initiated by JD.com, which drove margin compression and weighed on earnings expectations. Broader weakness across the Chinese consumer further exacerbated the stock's decline, as did rising competitive threats. We exited the position on expectations for further downward pressure.

**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. The stock detracted in the fourth quarter after the company delivered weaker-than-expected margins due to losses in quick commerce and investments in cloud.

**Voltronic Power Technology** is a white-label, outsourced designer and manufacturer of uninterrupted power supply units and power inverters used in applications including solar, energy storage, and electrical vehicle chargers. The stock underperformed during the year following rising competition, particularly from China, and weakening end-market demand. The position was exited on near-term weakness.

**WEG** is a Brazilian manufacturer of industrial machinery. The company provides products including electric motors, power and distribution transformers, large motors, direct current motors, generators, drives, programmable controllers, electric panels, and electrical components. The stock's underperformance was in part driven by a challenging geopolitical backdrop coupled with negative currency effects. Margin compression also weighed on profitability, largely due to higher raw material costs. The position was exited during the period.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Eurobank Ergasias Services** is one of four systemic Greek banks that benefit from above-average growth in the eurozone. It offers retail and commercial banking, asset management, investment banking, and insurance services in Greece. It is differentiated from other Greek banks through its M&A-focused expansion strategy outside of Greece, which is focused on Cyprus and Bulgaria. The bank benefits from scale and has a track record of strong capital allocation leading to above-average growth and returns.

**Delta Electronics** delivered robust returns as demand for AI data center infrastructure, power electronics, and liquid cooling systems accelerated, with disciplined margin execution further reinforcing investor confidence. The position was exited on valuation concerns following a period of strong performance.

**ASPEED Technology** contributed the most amid strong performance, as the company benefited from accelerating demand for AI server infrastructure and continued strength in enterprise cloud spending.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_42028.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Leaders Fund Class N** | 26.05% | -0.77% | 6.35% |
| **MSCI Emerging Markets Index (net)** | 33.57% | 4.20% | 8.42% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$95763 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;51 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$990 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;79% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 13.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 6.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 3.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;NU Holdings Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;NetEase, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Contemporary Amperex Technology Co. Ltd. | 2.4% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_41997.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42002.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Leaders Fund

#### Class R6 / WELIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Leaders Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Leaders Fund Class R6 | $106 | 0.94% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 26.42% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets Index (net), which returned 33.57%. The Fund's benchmark is also a broad measure of market performance.

The Fund's underperformance versus its benchmark during the year was driven by a combination of stock selection in Consumer Discretionary and Industrials, and sector allocation effects. Weak stock selection within Consumer Discretionary and Industrials were the primary drivers of underperformance. From a sector allocation perspective, an underweight to Materials and an overweight to Information Technology also weighed on relative returns.

#### TOP PERFORMANCE DETRACTORS
**Trip.com** is China's leading online travel agency, with a dominant market share. While fundamental performance continues to benefit from the structural growth in Chinese consumers' travel spending, the stock price declined earlier in the year after management reduced expected margins as it is looking to expand the platform internationally. More recently, fluctuations in market perception of artificial intelligence ("AI") disruption risk are expected to weigh on near-term multiples, creating stock overhang.

**Meituan** is the leading Chinese online platform for food delivery and local services, and it also offers hotel and travel booking services. The company underperformed in 2025, primarily due to intensifying competitive pressure, most notably a price war initiated by JD.com, which drove margin compression and weighed on earnings expectations. Broader weakness across the Chinese consumer further exacerbated the stock's decline, as did rising competitive threats. We exited the position on expectations for further downward pressure.

**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. The stock detracted in the fourth quarter after the company delivered weaker-than-expected margins due to losses in quick commerce and investments in cloud.

**Voltronic Power Technology** is a white-label, outsourced designer and manufacturer of uninterrupted power supply units and power inverters used in applications including solar, energy storage, and electrical vehicle chargers. The stock underperformed during the year following rising competition, particularly from China, and weakening end-market demand. The position was exited on near-term weakness.

**WEG** is a Brazilian manufacturer of industrial machinery. The company provides products including electric motors, power and distribution transformers, large motors, direct current motors, generators, drives, programmable controllers, electric panels, and electrical components. The stock's underperformance was in part driven by a challenging geopolitical backdrop coupled with negative currency effects. Margin compression also weighed on profitability, largely due to higher raw material costs. The position was exited during the period.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Eurobank Ergasias Services** is one of four systemic Greek banks that benefit from above-average growth in the eurozone. It offers retail and commercial banking, asset management, investment banking, and insurance services in Greece. It is differentiated from other Greek banks through its M&A-focused expansion strategy outside of Greece, which is focused on Cyprus and Bulgaria. The bank benefits from scale and has a track record of strong capital allocation leading to above-average growth and returns.

**Delta Electronics** delivered robust returns as demand for AI data center infrastructure, power electronics, and liquid cooling systems accelerated, with disciplined margin execution further reinforcing investor confidence. The position was exited on valuation concerns following a period of strong performance.

**ASPEED Technology** contributed the most amid strong performance, as the company benefited from accelerating demand for AI server infrastructure and continued strength in enterprise cloud spending.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_42101.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Leaders Fund Class R6** | 26.42% | -0.46% | 6.68% |
| **MSCI Emerging Markets Index (net)** | 33.57% | 4.20% | 8.42% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$95763 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;51 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$990 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;79% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 13.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 6.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 3.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;NU Holdings Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;NetEase, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Contemporary Amperex Technology Co. Ltd. | 2.4% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42069.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42074.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Growth Fund

#### Class I / WBEIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Growth Fund Class I | $111 | 0.99% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 25.18% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets IMI (net), which returned 31.38%. The Fund's benchmark is also a broad measure of market performance.

Underperformance versus its benchmark during the year was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection effect within Consumer Discretionary and Financials, coupled with an underweight to Materials. These negative effects were partially offset by strong stock selection effect within information technology and sector overweighting.

#### TOP PERFORMANCE DETRACTORS
**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. The stock detracted in the fourth quarter after the company delivered weaker-than-expected margins due to losses in quick commerce and investments in cloud.

**Trip.com** is China's leading online travel agency, with a dominant market share. While fundamental performance continues to benefit from the structural growth in Chinese consumers' travel spending, the stock price declined earlier in the year after management reduced expected margins as it is looking to expand the platform internationally. More recently, fluctuations in market perception of artificial intelligence ("AI") disruption risk are expected to weigh on near-term multiples, creating stock overhang.

**Bank Central Asia**, Indonesia's largest private bank, declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns over the new administration reshuffle and sovereign wealth fund Danantara implementation.

**ICICI Bank**, one of India's largest private sector banks, underperformed due to margin compression and a normalization in loan growth. Investor concerns about rate cuts and asset quality weighed on sentiment.

**Banco Galicia**, along with broader Argentine equities, posted strong gains in 2024 amid optimism about political change and early signs of macro stabilization. However, in 2025, the stock corrected as market enthusiasm moderated amid rising concerns about inflation, policy execution, and renewed currency volatility, which triggered profit-taking.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Delta Electronics**' stock rally this year was supported by robust demand for AI data center infrastructure, power electronics, and high-voltage direct current solutions. The company's expansion in Southeast Asia and disciplined margin execution have further reinforced investor confidence.

**Taiwan Semiconductor Manufacturing Co. Ltd.**, a multinational semiconductor contract manufacturing and design company, added meaningfully on sustained demand for advanced semiconductor nodes and high-performance computing chips, benefiting from the ramp-up of 3 nm technology and progress toward 2 nm, which reinforced its leadership and supported record revenue growth.

**Hanwha Aerospace** is the leading South Korean defense and aerospace manufacturer. The company benefited from rising demand for aerospace and defense systems, particularly amid heightened geopolitical tensions and increased global defense spending. Strategic consolidation of Hanwha Ocean and positive analyst upgrades boosted investor confidence and drove the share price outperformance.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_42173.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Growth Fund Class I** | 25.18% | 1.05% | 8.52% |
| **MSCI Emerging Markets IMI (net)** | 31.38% | 4.66% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1014486 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;112 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$7461 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;84% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 14.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 6.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 5.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Naspers Limited | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Reliance Industries Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;ICICI Bank Ltd. | 1.5% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42141.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42146.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Growth Fund

#### Class N / WBENX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Growth Fund Class N | $139 | 1.24% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 24.84% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets IMI (net), which returned 31.38%. The Fund's benchmark is also a broad measure of market performance.

Underperformance versus its benchmark during the year was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection effect within Consumer Discretionary and Financials, coupled with an underweight to Materials. These negative effects were partially offset by strong stock selection effect within information technology and sector overweighting.

#### TOP PERFORMANCE DETRACTORS
**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. The stock detracted in the fourth quarter after the company delivered weaker-than-expected margins due to losses in quick commerce and investments in cloud.

**Trip.com** is China's leading online travel agency, with a dominant market share. While fundamental performance continues to benefit from the structural growth in Chinese consumers' travel spending, the stock price declined earlier in the year after management reduced expected margins as it is looking to expand the platform internationally. More recently, fluctuations in market perception of artificial intelligence ("AI") disruption risk are expected to weigh on near-term multiples, creating stock overhang.

**Bank Central Asia**, Indonesia's largest private bank, declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns over the new administration reshuffle and sovereign wealth fund Danantara implementation.

**ICICI Bank**, one of India's largest private sector banks, underperformed due to margin compression and a normalization in loan growth. Investor concerns about rate cuts and asset quality weighed on sentiment.

**Banco Galicia**, along with broader Argentine equities, posted strong gains in 2024 amid optimism about political change and early signs of macro stabilization. However, in 2025, the stock corrected as market enthusiasm moderated amid rising concerns about inflation, policy execution, and renewed currency volatility, which triggered profit-taking.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Delta Electronics**' stock rally this year was supported by robust demand for AI data center infrastructure, power electronics, and high-voltage direct current solutions. The company's expansion in Southeast Asia and disciplined margin execution have further reinforced investor confidence.

**Taiwan Semiconductor Manufacturing Co. Ltd.**, a multinational semiconductor contract manufacturing and design company, added meaningfully on sustained demand for advanced semiconductor nodes and high-performance computing chips, benefiting from the ramp-up of 3 nm technology and progress toward 2 nm, which reinforced its leadership and supported record revenue growth.

**Hanwha Aerospace** is the leading South Korean defense and aerospace manufacturer. The company benefited from rising demand for aerospace and defense systems, particularly amid heightened geopolitical tensions and increased global defense spending. Strategic consolidation of Hanwha Ocean and positive analyst upgrades boosted investor confidence and drove the share price outperformance.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_42131.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Growth Fund Class N** | 24.84% | 0.80% | 8.24% |
| **MSCI Emerging Markets IMI (net)** | 31.38% | 4.66% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1014486 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;112 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$7461 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;84% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 14.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 6.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 5.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Naspers Limited | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Reliance Industries Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;ICICI Bank Ltd. | 1.5% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42117.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42112.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Growth Fund

#### Class R6 / BIEMX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Growth Fund Class R6 | $106 | 0.94% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 25.23% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets IMI (net), which returned 31.38%. The Fund's benchmark is also a broad measure of market performance.

Underperformance versus its benchmark during the year was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection effect within Consumer Discretionary and Financials, coupled with an underweight to Materials. These negative effects were partially offset by strong stock selection effect within information technology and sector overweighting.

#### TOP PERFORMANCE DETRACTORS
**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. The stock detracted in the fourth quarter after the company delivered weaker-than-expected margins due to losses in quick commerce and investments in cloud.

**Trip.com** is China's leading online travel agency, with a dominant market share. While fundamental performance continues to benefit from the structural growth in Chinese consumers' travel spending, the stock price declined earlier in the year after management reduced expected margins as it is looking to expand the platform internationally. More recently, fluctuations in market perception of artificial intelligence ("AI") disruption risk are expected to weigh on near-term multiples, creating stock overhang.

**Bank Central Asia**, Indonesia's largest private bank, declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns over the new administration reshuffle and sovereign wealth fund Danantara implementation.

**ICICI Bank**, one of India's largest private sector banks, underperformed due to margin compression and a normalization in loan growth. Investor concerns about rate cuts and asset quality weighed on sentiment.

**Banco Galicia**, along with broader Argentine equities, posted strong gains in 2024 amid optimism about political change and early signs of macro stabilization. However, in 2025, the stock corrected as market enthusiasm moderated amid rising concerns about inflation, policy execution, and renewed currency volatility, which triggered profit-taking.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based AI enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Delta Electronics**' stock rally this year was supported by robust demand for AI data center infrastructure, power electronics, and high-voltage direct current solutions. The company's expansion in Southeast Asia and disciplined margin execution have further reinforced investor confidence.

**Taiwan Semiconductor Manufacturing Co. Ltd.**, a multinational semiconductor contract manufacturing and design company, added meaningfully on sustained demand for advanced semiconductor nodes and high-performance computing chips, benefiting from the ramp-up of 3 nm technology and progress toward 2 nm, which reinforced its leadership and supported record revenue growth.

**Hanwha Aerospace** is the leading South Korean defense and aerospace manufacturer. The company benefited from rising demand for aerospace and defense systems, particularly amid heightened geopolitical tensions and increased global defense spending. Strategic consolidation of Hanwha Ocean and positive analyst upgrades boosted investor confidence and drove the share price outperformance.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_42203.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Growth Fund Class R6** | 25.23% | 1.11% | 8.59% |
| **MSCI Emerging Markets IMI (net)** | 31.38% | 4.66% | 8.37% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$1014486 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;112 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$7461 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;84% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 14.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 6.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 5.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 4.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Naspers Limited | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Reliance Industries Ltd. | 1.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;ICICI Bank Ltd. | 1.5% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42189.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42184.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets ex China Growth Fund

#### Class I / WXCIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets ex China Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets ex China Growth Fund Class I | $113 | 0.99% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 28.18% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets ex-China IMI (net), which returned 31.42%. The Fund's benchmark is also a broad measure of market performance.

Underperformance versus its benchmark during the year was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection within Consumer Discretionary and Financials, coupled with an overweight to Consumer Discretionary and an underweight to Materials.

#### TOP PERFORMANCE DETRACTORS
**The Indian Hotels Co.**'s shares declined as margin pressure and weaker-than-expected earnings offset robust top-line growth. Wage inflation, cancellations, and operational inefficiencies weighed on profitability, while broader weakness in Indian mid-cap equities added to the headwind.

**Naspers** detracted due to the lack of exposure throughout the year, especially as the stock rallied on the back of its Tencent exposure and narrowing holding company discount.

**Eternal**'s weakness was primarily driven by increasing capital-led competitive intensity and near-term margin compression in food delivery and quick commerce.

**Grupo Financiero Galicia SA** and **Banco Bbva Argentina SA**, Argentine banks, were significant detractors to relative returns due to investor caution around Argentina's financial sector and broad macroeconomic and foreign exchange headwinds amid a weakening peso.

**Bank Central Asia**, Indonesia's largest private bank, declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns over the new administration reshuffle and sovereign wealth fund Danantara implementation.

**ICICI Bank**, one of India's largest private sector banks, underperformed due to margin compression and a normalization in loan growth. Investor concerns around asset quality weighed on sentiment.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based artificial intelligence ("AI") enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Delta Electronics** delivered robust returns as demand for AI data center infrastructure, power electronics, and liquid cooling systems accelerated, with disciplined margin execution further reinforcing investor confidence.

**Taiwan Semiconductor Manufacturing Co. Ltd.** ("TSMC"), a multinational semiconductor contract manufacturing and design company, added meaningfully on sustained demand for advanced semiconductor nodes and high-performance computing chips, benefiting from the ramp-up of 3 nm technology and progress toward 2 nm, which reinforced its leadership and supported record revenue growth.

**Elite Material**, a manufacturer of copper clad laminates, advanced on the build-out of AI infrastructure, as next-generation server and networking platforms required increasingly complex, high-layer PCBs, driving volume growth and margin expansion.

**Hanwha Aerospace Co Ltd.** is the leading South Korean defense and aerospace manufacturer. The company benefited from rising demand for aerospace and defense systems, particularly amid heightened geopolitical tensions and increased global defense spending. Strategic consolidation of Hanwha Ocean and positive analyst upgrades boosted investor confidence and drove the share price outperformance.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_42245.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Emerging Markets ex China Growth Fund Class I** | 28.18% | 16.88% |
| **MSCI Emerging Markets ex-China IMI (net)** | 31.42% | 15.41% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$57589 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;95 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$47 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;84% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 16.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 6.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 5.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;MercadoLibre, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Delta Electronics, Inc. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Sea Ltd. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;ICICI Bank Ltd. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Naspers Limited | 1.8% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42214.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42219.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets ex China Growth Fund

#### Class R6 / WXCRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets ex China Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets ex China Growth Fund Class R6 | $107 | 0.94% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 28.25% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets ex-China IMI (net), which returned 31.42%. The Fund's benchmark is also a broad measure of market performance.

Underperformance versus its benchmark during the year was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection within Consumer Discretionary and Financials, coupled with an overweight to Consumer Discretionary and an underweight to Materials.

#### TOP PERFORMANCE DETRACTORS
**The Indian Hotels Co.**'s shares declined as margin pressure and weaker-than-expected earnings offset robust top-line growth. Wage inflation, cancellations, and operational inefficiencies weighed on profitability, while broader weakness in Indian mid-cap equities added to the headwind.

**Naspers** detracted due to the lack of exposure throughout the year, especially as the stock rallied on the back of its Tencent exposure and narrowing holding company discount.

**Eternal**'s weakness was primarily driven by increasing capital-led competitive intensity and near-term margin compression in food delivery and quick commerce.

**Grupo Financiero Galicia SA** and **Banco Bbva Argentina SA**, Argentine banks, were significant detractors to relative returns due to investor caution around Argentina's financial sector and broad macroeconomic and foreign exchange headwinds amid a weakening peso.

**Bank Central Asia**, Indonesia's largest private bank, declined amid a deteriorated macroeconomic backdrop in Indonesia, rupiah weakness, and investor concerns over the new administration reshuffle and sovereign wealth fund Danantara implementation.

**ICICI Bank**, one of India's largest private sector banks, underperformed due to margin compression and a normalization in loan growth. Investor concerns around asset quality weighed on sentiment.

#### TOP PERFORMANCE CONTRIBUTORS
**SK Hynix** is a South Korea–based artificial intelligence ("AI") enabler and a pure-play manufacturer of memory semiconductors focusing on DRAM and NAND. The stock appreciated on expectations for continued AI demand and tailwinds for Korean equities following the presidential election in early June, which brought hopes of an increase in political stability and investor-friendly reforms in corporate governance. Strong demand and pricing power supported continued earnings momentum.

**Delta Electronics** delivered robust returns as demand for AI data center infrastructure, power electronics, and liquid cooling systems accelerated, with disciplined margin execution further reinforcing investor confidence.

**Taiwan Semiconductor Manufacturing Co. Ltd.** ("TSMC"), a multinational semiconductor contract manufacturing and design company, added meaningfully on sustained demand for advanced semiconductor nodes and high-performance computing chips, benefiting from the ramp-up of 3 nm technology and progress toward 2 nm, which reinforced its leadership and supported record revenue growth.

**Elite Material**, a manufacturer of copper clad laminates, advanced on the build-out of AI infrastructure, as next-generation server and networking platforms required increasingly complex, high-layer PCBs, driving volume growth and margin expansion.

**Hanwha Aerospace Co Ltd.** is the leading South Korean defense and aerospace manufacturer. The company benefited from rising demand for aerospace and defense systems, particularly amid heightened geopolitical tensions and increased global defense spending. Strategic consolidation of Hanwha Ocean and positive analyst upgrades boosted investor confidence and drove the share price outperformance.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_42276.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Emerging Markets ex China Growth Fund Class R6** | 28.25% | 16.96% |
| **MSCI Emerging Markets ex-China IMI (net)** | 31.42% | 15.41% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$57589 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;95 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$47 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;84% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Semiconductor Manufacturing Co. Ltd. | 16.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Samsung Electronics Co. Ltd. | 6.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;SK Hynix, Inc. | 5.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;HDFC Bank Ltd. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;MercadoLibre, Inc. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bharti Airtel Ltd. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Delta Electronics, Inc. | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Sea Ltd. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;ICICI Bank Ltd. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Naspers Limited | 1.8% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42261.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42257.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Small Cap Growth Fund

#### Class I / BESIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Small Cap Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Small Cap Growth Fund Class I | $123 | 1.15% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 13.94% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets Small Cap Index (net), which returned 18.58% and underperformed the MSCI Emerging Markets IMI (net), a broad measure of market performance, which returned 31.38%.

Underperformance versus the benchmark was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection within Financials, Industrials, and Health Care. Within financials, stock selection within capital market names and banks was the main drag to relative performance. Partially mitigating these negative effects was the positive stock selection effect in Materials and Taiwan. The Financials overweighting and allocation effect in technology also added to relative results.

#### TOP PERFORMANCE DETRACTORS
**Central Depository Services India Ltd**, a key infrastructure provider for India's capital markets, underperformed due to weakening operating momentum as slowing transaction volumes and elevated technology costs pressured margins.

**Kfin Technologies**, another Indian capital market firm, declined on margin contraction and slower-than-expected client acquisition in a competitive market leading to margin contraction.

**Bank Syariah Indonesia** (BSI), the country's largest Sharia-compliant bank, was a drag as loan growth decelerated and funding-cost headwinds persisted.

**Transformers & Rectifiers India**, an Indian power-equipment manufacturer, corrected after the company delivered weaker-than-expected fiscal second quarter 2026 results, as order inflow fell while working-capital and staff and other expenses pressed profitability.

**HD Hyundai Marine Solution Co. Ltd**, Korea's marine services and ship lifecycle-management provider, detracted amid a share placement earlier in the year and as order timing and retrofit mix skewed less favorably into the year-end, despite long-term tailwinds from the shipbuilding cycle and the shift to dual-fuel engines.

In Brazil, **Marcopolo**, the bus and coach manufacturer, lagged due to weaker domestic volume growth and ongoing elevated interest rates.

**Anthem Biosciences**, an India-based CDMO, was a notable detractor. The stock underperformed as revenue momentum disappointed, with destocking at a key client Pfizer, flat orders at AbbVie and new wins progressing more gradually than expected.

#### TOP PERFORMANCE CONTRIBUTORS
**Industrias Peñoles**, Mexico's diversified miner, benefited from favorable precious metals pricing and solid production trends, with cost discipline and operational improvements supporting sustained margin expansion.

**Fresnillo**, a leading silver producer, added on robust silver prices and operational enhancements that improved output reliability and underpinned free cash flow resilience.

**Pan African Resources**, the South African gold producer, outperformed amid favorable gold price environment and the company's strong execution as steady production and tight grade control translated into reliable cash generation.

**ASPEED Technology**, the server-management silicon leader (BMCs), benefited from hyperscalers and enterprise artificial intelligence ("AI") server build-outs, content gains in next-gen platforms, and disciplined pricing, which supported resilient gross margins.

**Hon Precision** contributed as AI server programs scaled, shifting mix away from legacy consumer electronics and improving profitability at rack/system level.

**Taiwan Union Technology** (TUC) was boosted by strong orders, high utilization for high-layer server and networking boards, as well as customer wins. Furthermore, adoption of low-loss, high-reliability materials meeting AI data center specifications supported sustained margin expansion.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_42347.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Small Cap Growth Fund Class I** | 13.94% | 4.67% | 7.47% |
| **MSCI Emerging Markets IMI (net)** | 31.38% | 4.66% | 8.37% |
| **MSCI Emerging Markets Small Cap Index (net)** | 18.58% | 8.43% | 8.31% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$367783 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;121 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$3089 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;261% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;ASELSAN Elektronik Sanayi ve Ticaret A.S. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;GE Vernova T&D India Ltd. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon. Precision, Inc | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Neway Valve (Suzhou) Co., Ltd. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;JB Financial Group Co. Ltd. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;BNK Financial Group, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Laureate Education, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Union Technology Corporation | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airtel Africa PLC | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Karur Vysya Bank Ltd. | 1.7% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42334.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42328.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Small Cap Growth Fund

#### Class N / WESNX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Small Cap Growth Fund Class N (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Small Cap Growth Fund Class N | $150 | 1.40% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 13.68% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets Small Cap Index (net), which returned 18.58% and underperformed the MSCI Emerging Markets IMI (net), a broad measure of market performance, which returned 31.38%.

Underperformance versus the benchmark was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection within Financials, Industrials, and Health Care. Within financials, stock selection within capital market names and banks was the main drag to relative performance. Partially mitigating these negative effects was the positive stock selection effect in Materials and Taiwan. The Financials overweighting and allocation effect in technology also added to relative results.

#### TOP PERFORMANCE DETRACTORS
**Central Depository Services India Ltd**, a key infrastructure provider for India's capital markets, underperformed due to weakening operating momentum as slowing transaction volumes and elevated technology costs pressured margins.

**Kfin Technologies**, another Indian capital market firm, declined on margin contraction and slower-than-expected client acquisition in a competitive market leading to margin contraction.

**Bank Syariah Indonesia** (BSI), the country's largest Sharia-compliant bank, was a drag as loan growth decelerated and funding-cost headwinds persisted.

**Transformers & Rectifiers India**, an Indian power-equipment manufacturer, corrected after the company delivered weaker-than-expected fiscal second quarter 2026 results, as order inflow fell while working-capital and staff and other expenses pressed profitability.

**HD Hyundai Marine Solution Co. Ltd**, Korea's marine services and ship lifecycle-management provider, detracted amid a share placement earlier in the year and as order timing and retrofit mix skewed less favorably into the year-end, despite long-term tailwinds from the shipbuilding cycle and the shift to dual-fuel engines.

In Brazil, **Marcopolo**, the bus and coach manufacturer, lagged due to weaker domestic volume growth and ongoing elevated interest rates.

**Anthem Biosciences**, an India-based CDMO, was a notable detractor. The stock underperformed as revenue momentum disappointed, with destocking at a key client Pfizer, flat orders at AbbVie and new wins progressing more gradually than expected.

#### TOP PERFORMANCE CONTRIBUTORS
**Industrias Peñoles**, Mexico's diversified miner, benefited from favorable precious metals pricing and solid production trends, with cost discipline and operational improvements supporting sustained margin expansion.

**Fresnillo**, a leading silver producer, added on robust silver prices and operational enhancements that improved output reliability and underpinned free cash flow resilience.

**Pan African Resources**, the South African gold producer, outperformed amid favorable gold price environment and the company's strong execution as steady production and tight grade control translated into reliable cash generation.

**ASPEED Technology**, the server-management silicon leader (BMCs), benefited from hyperscalers and enterprise artificial intelligence ("AI") server build-outs, content gains in next-gen platforms, and disciplined pricing, which supported resilient gross margins.

**Hon Precision** contributed as AI server programs scaled, shifting mix away from legacy consumer electronics and improving profitability at rack/system level.

**Taiwan Union Technology** (TUC) was boosted by strong orders, high utilization for high-layer server and networking boards, as well as customer wins. Furthermore, adoption of low-loss, high-reliability materials meeting AI data center specifications supported sustained margin expansion.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $10,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $10,000
![Fund Performance - Growth of 10K](chartimages_42317.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Small Cap Growth Fund Class N** | 13.68% | 4.41% | 7.19% |
| **MSCI Emerging Markets IMI (net)** | 31.38% | 4.66% | 8.37% |
| **MSCI Emerging Markets Small Cap Index (net)** | 18.58% | 8.43% | 8.31% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$367783 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;121 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$3089 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;261% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;ASELSAN Elektronik Sanayi ve Ticaret A.S. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;GE Vernova T&D India Ltd. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon. Precision, Inc | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Neway Valve (Suzhou) Co., Ltd. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;JB Financial Group Co. Ltd. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;BNK Financial Group, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Laureate Education, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Union Technology Corporation | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airtel Africa PLC | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Karur Vysya Bank Ltd. | 1.7% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42286.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42291.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Small Cap Growth Fund

#### Class R6 / WESJX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Small Cap Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Small Cap Growth Fund Class R6 | $118 | 1.10% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 13.99% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI Emerging Markets Small Cap Index (net), which returned 18.58% and underperformed the MSCI Emerging Markets IMI (net), a broad measure of market performance, which returned 31.38%.

Underperformance versus the benchmark was primarily driven by weak performance in the first quarter amid strong style headwinds and sharp country rotation. From a sector perspective, the underperformance was primarily driven by negative stock selection within Financials, Industrials, and Health Care. Within financials, stock selection within capital market names and banks was the main drag to relative performance. Partially mitigating these negative effects was the positive stock selection effect in Materials and Taiwan. The Financials overweighting and allocation effect in technology also added to relative results.

#### TOP PERFORMANCE DETRACTORS
**Central Depository Services India Ltd**, a key infrastructure provider for India's capital markets, underperformed due to weakening operating momentum as slowing transaction volumes and elevated technology costs pressured margins.

**Kfin Technologies**, another Indian capital market firm, declined on margin contraction and slower-than-expected client acquisition in a competitive market leading to margin contraction.

**Bank Syariah Indonesia** (BSI), the country's largest Sharia-compliant bank, was a drag as loan growth decelerated and funding-cost headwinds persisted.

**Transformers & Rectifiers India**, an Indian power-equipment manufacturer, corrected after the company delivered weaker-than-expected fiscal second quarter 2026 results, as order inflow fell while working-capital and staff and other expenses pressed profitability.

**HD Hyundai Marine Solution Co. Ltd**, Korea's marine services and ship lifecycle-management provider, detracted amid a share placement earlier in the year and as order timing and retrofit mix skewed less favorably into the year-end, despite long-term tailwinds from the shipbuilding cycle and the shift to dual-fuel engines.

In Brazil, **Marcopolo**, the bus and coach manufacturer, lagged due to weaker domestic volume growth and ongoing elevated interest rates.

**Anthem Biosciences**, an India-based CDMO, was a notable detractor. The stock underperformed as revenue momentum disappointed, with destocking at a key client Pfizer, flat orders at AbbVie and new wins progressing more gradually than expected.

#### TOP PERFORMANCE CONTRIBUTORS
**Industrias Peñoles**, Mexico's diversified miner, benefited from favorable precious metals pricing and solid production trends, with cost discipline and operational improvements supporting sustained margin expansion.

**Fresnillo**, a leading silver producer, added on robust silver prices and operational enhancements that improved output reliability and underpinned free cash flow resilience.

**Pan African Resources**, the South African gold producer, outperformed amid favorable gold price environment and the company's strong execution as steady production and tight grade control translated into reliable cash generation.

**ASPEED Technology**, the server-management silicon leader (BMCs), benefited from hyperscalers and enterprise artificial intelligence ("AI") server build-outs, content gains in next-gen platforms, and disciplined pricing, which supported resilient gross margins.

**Hon Precision** contributed as AI server programs scaled, shifting mix away from legacy consumer electronics and improving profitability at rack/system level.

**Taiwan Union Technology** (TUC) was boosted by strong orders, high utilization for high-layer server and networking boards, as well as customer wins. Furthermore, adoption of low-loss, high-reliability materials meeting AI data center specifications supported sustained margin expansion.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_42388.jpg)

---

| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **5 Years** | **10 Years** |
| **Emerging Markets Small Cap Growth Fund Class R6** | 13.99% | 4.73% | 7.53% |
| **MSCI Emerging Markets IMI (net)** | 31.38% | 4.66% | 8.37% |
| **MSCI Emerging Markets Small Cap Index (net)** | 18.58% | 8.43% | 8.31% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$367783 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;121 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$3089 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;261% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;ASELSAN Elektronik Sanayi ve Ticaret A.S. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;GE Vernova T&D India Ltd. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hon. Precision, Inc | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Neway Valve (Suzhou) Co., Ltd. | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;JB Financial Group Co. Ltd. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;BNK Financial Group, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Laureate Education, Inc. | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Taiwan Union Technology Corporation | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airtel Africa PLC | 1.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Karur Vysya Bank Ltd. | 1.7% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42357.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42362.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair China Growth Fund

#### Class I / WICGX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair China Growth Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| China Growth Fund Class I | $111 | 0.99% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 24.25% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI China All Shares Index (net), which returned 28.94%. The Fund's benchmark is also a broad measure of market performance.

Underperformance versus its benchmark was driven by a combination of allocation and stock selection effects. An underweight allocation to Materials, overweight allocation and stock selection to Consumer Discretionary, and negative stock selection within Financials were the primary drivers of underperformance. Partially offsetting these effects was an underweight allocation to Real Estate, coupled with positive stock selection within Information Technology.

#### TOP PERFORMANCE DETRACTORS
**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. Alibaba detracted amid weaker fundamental performance in fiscal second quarter, driven by losses in quick commerce. The stock underperformed despite robust artificial intelligence ("AI") demand driving cloud revenue acceleration 34% year-over-year and upbeat management outlook on AI supply demand dynamics.

**East Money** operates an online financial information platform. East Money's products include internet advertising and financial data. East Money underperformed in 2025 mainly due to weaker-than-expected growth in its brokerage and wealth management businesses amid a sluggish Chinese equity market. Additionally, competitive pricing and higher operating costs weighed on margins.

**Futu**, through its subsidiaries, offers an online brokerage platform that enables individual investors to trade in listed stocks. Futu reported solid top-line growth in 2025; however, profitability was pressured by lower commission rates and operating expenses rose significantly due to marketing and compliance costs, which weighed on margins.

#### TOP PERFORMANCE CONTRIBUTORS
**Eoptolink Technology** is a leading optical transceiver manufacturer, with products covering up to 800G optical transceivers currently. Eoptolink is strategically positioned to benefit from the ramp-up in 400G/800G volumes, driven by its key customers' deployment of these transceivers in AI infrastructure. Eoptolink's strong performance was driven by surging demand for high-speed optical transceivers in AI data centers and cloud infrastructure.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_42420.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **China Growth Fund Class I** | 24.25% | -8.78% |
| **MSCI China All Shares Index (net)** | 28.94% | -0.42% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$2078 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;48 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$0 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;73% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 14.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 10.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Contemporary Amperex Technology Co. Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Zhongji Innolight Co. Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Eoptolink Technology Inc., Ltd. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;NetEase, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Zijin Mining Group Company Limited | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Foxconn Industrial Internet Co. Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Trip.com Group Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;China Merchants Bank Co. Ltd. | 2.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42404.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42399.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair China Growth Fund

#### Class R6 / WRCGX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair China Growth Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| China Growth Fund Class R6 | $105 | 0.94% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 24.21% (net of fees) for the 12 months ended December 31, 2025. The Fund underperformed its benchmark, the MSCI China All Shares Index (net), which returned 28.94%. The Fund's benchmark is also a broad measure of market performance.

Underperformance versus its benchmark was driven by a combination of allocation and stock selection effects. An underweight allocation to Materials, overweight allocation and stock selection to Consumer Discretionary, and negative stock selection within Financials were the primary drivers of underperformance. Partially offsetting these effects was an underweight allocation to Real Estate, coupled with positive stock selection within Information Technology.

#### TOP PERFORMANCE DETRACTORS
**Alibaba** is a major Chinese technology conglomerate with e-commerce, cloud, and digital media assets. Alibaba detracted amid weaker fundamental performance in fiscal second quarter, driven by losses in quick commerce. The stock underperformed despite robust artificial intelligence ("AI") demand driving cloud revenue acceleration 34% year-over-year and upbeat management outlook on AI supply demand dynamics.

**East Money** operates an online financial information platform. East Money's products include internet advertising and financial data. East Money underperformed in 2025 mainly due to weaker-than-expected growth in its brokerage and wealth management businesses amid a sluggish Chinese equity market. Additionally, competitive pricing and higher operating costs weighed on margins.

**Futu**, through its subsidiaries, offers an online brokerage platform that enables individual investors to trade in listed stocks. Futu reported solid top-line growth in 2025; however, profitability was pressured by lower commission rates and operating expenses rose significantly due to marketing and compliance costs, which weighed on margins.

#### TOP PERFORMANCE CONTRIBUTORS
**Eoptolink Technology** is a leading optical transceiver manufacturer, with products covering up to 800G optical transceivers currently. Eoptolink is strategically positioned to benefit from the ramp-up in 400G/800G volumes, driven by its key customers' deployment of these transceivers in AI infrastructure. Eoptolink's strong performance was driven by surging demand for high-speed optical transceivers in AI data centers and cloud infrastructure.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index which is also generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_42460.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **China Growth Fund Class R6** | 24.21% | -8.81% |
| **MSCI China All Shares Index (net)** | 28.94% | -0.42% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$2078 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;48 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$0 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;73% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Tencent Holdings Ltd. | 14.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Alibaba Group Holding Ltd. | 10.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Contemporary Amperex Technology Co. Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Zhongji Innolight Co. Ltd. | 3.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Eoptolink Technology Inc., Ltd. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;NetEase, Inc. | 3.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Zijin Mining Group Company Limited | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Foxconn Industrial Internet Co. Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Trip.com Group Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;China Merchants Bank Co. Ltd. | 2.3% |

---

Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_42429.jpg)

Geographic Diversification

![Graphical Representation - Allocation 2 Chart](chartimages_42434.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Debt Fund

#### Class I / WEDIX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Debt Fund Class I (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Debt Fund Class I | $76 | 0.70% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 16.09% (net of fees) for the 12 months ended December 31, 2025. The Fund outperformed its benchmark, the J.P. Morgan Emerging Markets Bond Index (EMBI) Global Diversified Index (the "Index"), which returned 14.30% and outperformed the Bloomberg Global Aggregate Index, a broad measure of market performance, which returned 8.17%.

Positive contributions came from all three "beta buckets" (or risk categories), particularly the high-beta (higher-risk) bucket. Both security selection and country allocation contributed positively to performance over the year.

#### Higher-Risk Countries
In **Venezuela**, our overweight position in Venezuela outperformed, as the market became more optimistic about regime change. The U.S. has applied military pressure in the region, which may slightly increase the probability of regime change in Venezuela; this would be a net positive for the bonds. Behavior of the bonds was volatile towards the end of 2025. Our view is that a comprehensive restructuring of the country's economy still remains many years away.

In **Lebanon**, our overweight position outperformed as bonds rallied on the appointment of a new prime minister and central bank governor. In addition, potential de-escalation of regional conflict further supported Lebanese bonds. The market anticipates an International Monetary Fund (IMF) agreement, which we believe could break the reform deadlock and enable the stalled debt restructuring to finally move forward.

In **Kenya**, we moved to an underweight position while the market continues to trade strongly. More friendly credit market conditions continue to attract new issuance, and Kenya was the latest high-yield issuer to return to the market with two new tranches with a 7- and 12-year maturity, respectively. Both were amortizing structures and were well received by the market.

In **Bolivia**, our underweight position detracted from performance, as a positive electoral outcome and support from multilaterals has reduced the probability of default in the near term. Significant structural reforms are needed for debt and macroeconomic stability, but the outlook for reforms has improved markedly.

#### Medium-Risk Countries
In **Mexico**, our overweight position in Pemex drove outperformance, as did our overweight position in the front end and long end of the Mexico sovereign curve. Both country selection and security selection contributed to performance.

In **Turkey**, our position in the local short-dated bond generated outperformance. Turkey still enjoys very high returns, a strong economic reform story, and limited depreciation of the currency. The central bank has once again started to ease monetary policy as inflation, albeit still high, has fallen significantly in recent months.

In **Trinidad and Tobago**, our overweight position detracted from performance, as it lagged peers. Concerns about Trinidad's relationship with Venezuela weighed on the outlook for some of the natural gas projects, which hurt sentiment.

We participated in **Kyrgyzstan**'s inaugural new issue at the end of May, which was well received by the market. Although it currently trades above the offer price, it has not been able to deliver a strong rally like the wider market, predominantly due to the shorter duration of the bond.

#### Lower-Risk Countries
In **China**, our underweight spread duration for sovereigns and quasi-sovereigns added to our outperformance. Spreads in China underperformed, primarily due to its tight valuations. Furthermore, the Chinese corporate credits we held were mostly flat performing in the fourth quarter of 2025 due to stagnant pricing.

In **Saudi Arabia**, our underweight position continued to contribute positively to performance in the fourth quarter of 2025. Investment-grade spreads remain at historically tight levels, offering limited upside, while issuance in the Saudi market has been abundant, adding supply pressure. Although non-oil growth remains robust and fiscal buffers are strong, valuations do not compensate for geopolitical risks and oil price volatility, reinforcing our cautious stance.

In **India**, we maintained an underweight position in sovereign risk due to tight valuations, while selectively holding corporate bonds that offer attractive valuations and positive credit trajectories. Although this positioning did not detract from absolute returns, the strong performance delivered by the broader EMD peer group meant that our net overweight exposure to India ultimately detracted from relative performance.

In **Jamaica**, our overweight position underperformed, as 2025 was a year characterized by high beta outperformance. Despite Hurricane Melissa making landfall on Jamaica, bond prices remained relatively resilient given the strong initial conditions, and deleveraging of the economy that had occurred over the last decade.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $500,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $500,000
![Fund Performance - Growth of 10K](chartimages_42492.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Emerging Markets Debt Fund Class I** | 16.09% | 3.58% |
| **Bloomberg Global Aggregate Index** | 8.17% | -1.82% |
| **J.P. Morgan Emerging Markets Bond Index (EMBI) Global Diversified Index** | 14.30% | 2.29% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$72998 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;248 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$114 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;120% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund. Credit quality designations range from AAA (highest) to D (lowest). Credit quality ratings on underlying securities are received from S&P and Moody's which are converted to the equivalent S&P major rating category for presentation purposes only.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Argentina Government International Bond | 3.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Egypt Government International Bond | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Dominican Republic International Bond | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Romania Government International Bond | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hungary Government International Bond | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Sri Lanka Government International Bond | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Ecuador Government International Bond | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Petroleos Mexicanos | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Oman Government International Bond | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Paraguay Government International Bond | 1.9% |

---

Geographic Diversification

![Graphical Representation - Allocation 1 Chart](chartimages_42477.jpg)

Credit Quality

![Graphical Representation - Allocation 2 Chart](chartimages_42472.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

### William Blair Emerging Markets Debt Fund

#### Class R6 / WEDRX
![WB - TSR - Fund Logo](images_581.jpg)

#### ANNUAL SHAREHOLDER REPORT \| December 31, 2025
This annual shareholder report contains important information about William Blair Emerging Markets Debt Fund Class R6 (the "Fund") for the period of January 1, 2025, to December 31, 2025.

You can find additional information about the Fund at

https://im.williamblair.com/investments/mutual-funds. You can also request this information by contacting us at 1-800-742-7272.

#### What were the Fund costs for the last year?
(Based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Fund** | **Cost of $10,000 Investment** | **Cost of $10,000 Investment as a percentage** |
| Emerging Markets Debt Fund Class R6 | $70 | 0.65% |

---

#### Management's Discussion of Fund Performance

#### SUMMARY OF RESULTS
The Fund returned 16.16% (net of fees) for the 12 months ended December 31, 2025. The Fund outperformed its benchmark, the J.P. Morgan Emerging Markets Bond Index (EMBI) Global Diversified Index (the "Index"), which returned 14.30% and outperformed the Bloomberg Global Aggregate Index, a broad measure of market performance, which returned 8.17%.

Positive contributions came from all three "beta buckets" (or risk categories), particularly the high-beta (higher-risk) bucket. Both security selection and country allocation contributed positively to performance over the year.

#### Higher-Risk Countries
In **Venezuela**, our overweight position in Venezuela outperformed, as the market became more optimistic about regime change. The U.S. has applied military pressure in the region, which may slightly increase the probability of regime change in Venezuela; this would be a net positive for the bonds. Behavior of the bonds was volatile towards the end of 2025. Our view is that a comprehensive restructuring of the country's economy still remains many years away.

In **Lebanon**, our overweight position outperformed as bonds rallied on the appointment of a new prime minister and central bank governor. In addition, potential de-escalation of regional conflict further supported Lebanese bonds. The market anticipates an International Monetary Fund (IMF) agreement, which we believe could break the reform deadlock and enable the stalled debt restructuring to finally move forward.

In **Kenya**, we moved to an underweight position while the market continues to trade strongly. More friendly credit market conditions continue to attract new issuance, and Kenya was the latest high-yield issuer to return to the market with two new tranches with a 7- and 12-year maturity, respectively. Both were amortizing structures and were well received by the market.

In **Bolivia**, our underweight position detracted from performance, as a positive electoral outcome and support from multilaterals has reduced the probability of default in the near term. Significant structural reforms are needed for debt and macroeconomic stability, but the outlook for reforms has improved markedly.

#### Medium-Risk Countries
In **Mexico**, our overweight position in Pemex drove outperformance, as did our overweight position in the front end and long end of the Mexico sovereign curve. Both country selection and security selection contributed to performance.

In **Turkey**, our position in the local short-dated bond generated outperformance. Turkey still enjoys very high returns, a strong economic reform story, and limited depreciation of the currency. The central bank has once again started to ease monetary policy as inflation, albeit still high, has fallen significantly in recent months.

In **Trinidad and Tobago**, our overweight position detracted from performance, as it lagged peers. Concerns about Trinidad's relationship with Venezuela weighed on the outlook for some of the natural gas projects, which hurt sentiment.

We participated in **Kyrgyzstan**'s inaugural new issue at the end of May, which was well received by the market. Although it currently trades above the offer price, it has not been able to deliver a strong rally like the wider market, predominantly due to the shorter duration of the bond.

#### Lower-Risk Countries
In **China**, our underweight spread duration for sovereigns and quasi-sovereigns added to our outperformance. Spreads in China underperformed, primarily due to its tight valuations. Furthermore, the Chinese corporate credits we held were mostly flat performing in the fourth quarter of 2025 due to stagnant pricing.

In **Saudi Arabia**, our underweight position continued to contribute positively to performance in the fourth quarter of 2025. Investment-grade spreads remain at historically tight levels, offering limited upside, while issuance in the Saudi market has been abundant, adding supply pressure. Although non-oil growth remains robust and fiscal buffers are strong, valuations do not compensate for geopolitical risks and oil price volatility, reinforcing our cautious stance.

In **India**, we maintained an underweight position in sovereign risk due to tight valuations, while selectively holding corporate bonds that offer attractive valuations and positive credit trajectories. Although this positioning did not detract from absolute returns, the strong performance delivered by the broader EMD peer group meant that our net overweight exposure to India ultimately detracted from relative performance.

In **Jamaica**, our overweight position underperformed, as 2025 was a year characterized by high beta outperformance. Despite Hurricane Melissa making landfall on Jamaica, bond prices remained relatively resilient given the strong initial conditions, and deleveraging of the economy that had occurred over the last decade.

#### Fund Performance
The following graph compares the initial and subsequent account values for the 10-year period ended December 31, 2025 (or for the life of the Fund, if shorter). It assumes a $1,000,000 initial investment at the beginning of the period and compares the Fund's performance to a broad-based securities market index and an additional index for the same period. The additional index is generally representative of the market sectors or types of investments in which the Fund invests.

#### GROWTH OF $1,000,000
![Fund Performance - Growth of 10K](chartimages_42532.jpg)

---

| | | |
|:---|:---|:---|
| **Average Annual Total Returns** | **1 Year** | **Since Inception** |
| **Emerging Markets Debt Fund Class R6** | 16.16% | 3.64% |
| **Bloomberg Global Aggregate Index** | 8.17% | -1.82% |
| **J.P. Morgan Emerging Markets Bond Index (EMBI) Global Diversified Index** | 14.30% | 2.29% |

---

Keep in mind that the Fund's past performance is not a good predictor of how the Fund will perform in the future.

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Visit

https://im.williamblair.com/investments/mutual-funds#performance-tab for the most recent performance information.

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$72998 |
| **Number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;248 |
| **Net advisory fees paid (in $000s)** | &nbsp;&nbsp;&nbsp;&nbsp;$114 |
| **Portfolio turnover rate** | &nbsp;&nbsp;&nbsp;&nbsp;120% |

---

#### Graphical Representation of Holdings
The tables below show the investment makeup of the Fund, representing percentage of the total net assets of the Fund. Credit quality designations range from AAA (highest) to D (lowest). Credit quality ratings on underlying securities are received from S&P and Moody's which are converted to the equivalent S&P major rating category for presentation purposes only.

Top Ten Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Argentina Government International Bond | 3.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Egypt Government International Bond | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Dominican Republic International Bond | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Romania Government International Bond | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Hungary Government International Bond | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Sri Lanka Government International Bond | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Ecuador Government International Bond | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Petroleos Mexicanos | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Oman Government International Bond | 1.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Paraguay Government International Bond | 1.9% |

---

Geographic Diversification

![Graphical Representation - Allocation 1 Chart](chartimages_42501.jpg)

Credit Quality

![Graphical Representation - Allocation 2 Chart](chartimages_42505.jpg)

#### Availability of Additional Information
You can find additional information about the Fund such as the prospectus, financial information, holdings and proxy voting information at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab. You can also request this information by contacting us at 1-800-742-7272.

#### Householding
In order to reduce expenses, we will deliver a single copy of prospectuses, proxies, financial reports and other communication to shareholders with the same residential address, provided they have the same last name or we reasonably believe them to be members of the same family. Unless we are notified otherwise, we will continue to send recipients only one copy of these materials for as long as they remain a shareholder of the Fund. If you would like to receive individual mailings, please call 1-800-742-7272 and we will begin sending you separate copies of these materials within 30 days after receiving your request.

![WB - TSR - QR Code](images_579.jpg)

For additional information, please scan the QR code at left to navigate to additional hosted material at

https://im.williamblair.com/investments/resources-us#prospectuses-and-reports-tab.

WILLIAM BLAIR FUNDS

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 1. Reports to Stockholders (continued).**

(b) Not applicable.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 2. Code of Ethics.**

(a) As of the end of the period covered by this report, the Registrant has adopted a code of ethics (the "Code") that applies to its principal executive officer and principal financial officer (the "Covered Officers").

(b) No disclosures are required pursuant to this Item 2(b).

(c) During the period covered by the report, the Registrant did not make any amendment to a provision of the Code.

(d) During the period covered by the report, the Registrant did not grant any waivers, including implicit waivers, from the provisions of the Code.

(e) Not applicable.

(f) A copy of the Code is filed as Exhibit 19(a)(1) to this Form N-CSR.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 3. Audit Committee Financial Expert.**

The Registrant's Board of Trustees has determined that the Registrant has at least one "audit committee financial expert" (as defined in Item 3 of Form N-CSR) serving on its Audit Committee. Mr. Daniel N. Leib, the Registrant's audit committee financial expert, is "independent" for purposes of Item 3 to Form N-CSR.

An "audit committee financial expert" is not an "expert" for any purpose, including for purposes of Section 11 of the Securities Act of 1933, as a result of being designated as an "audit committee financial expert." Further, the designation of a person as an "audit committee financial expert" does not mean that the person has any greater duties, obligations, or liability than those imposed on the person without the "audit committee financial expert" designation. Similarly, the designation of a person as an "audit committee financial expert" does not affect the duties, obligations, or liability of any other member of the audit committee or Board of Trustees.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 4. Principal Accountant Fees and Services.**

(a) Audit Fees

For the fiscal years ended December 31, 2024 and 2025, Ernst & Young LLP, the Registrant's principal accountant ("E&Y"), billed the Registrant $502,900 and $513,000, respectively, for professional services rendered for the audit of the Registrant's annual financial statements or services that are normally provided in connection with statutory and regulatory filings.

(b) Audit-Related Fees

For the fiscal years ended December 31, 2024 and 2025, E&Y billed the Registrant $0 and $0, respectively, for assurance and related services that are reasonably related to the performance of the audit of the Registrant's financial statements and that are not reported above. For the fiscal years ended December 31, 2024 and 2025, E&Y provided no audit-related services to William Blair Investment Management, LLC, the Registrant's investment adviser ("William Blair"), or any of its control affiliates that were for engagements directly related to the Registrant's operations and financial reporting.

(c) Tax Fees

For the fiscal years ended December 31, 2024 and 2025, E&Y billed the Registrant $167,135 and $270,015, respectively, for professional services rendered for tax compliance, tax advice and tax planning. Such services consisted of preparation of tax returns, year-end distribution review, qualifying dividend income analysis and review of year-end tax reporting. For the fiscal years ended December 31, 2024 and 2025, E&Y did not bill William Blair and its control affiliates for any services that were for engagements directly related to the Registrant's operations and financial reporting.

(d) All Other Fees

For the fiscal years ended December 31, 2024 and 2025, E&Y did not bill the Registrant for products and services other than the services reported above. For the fiscal years ended December 31, 2024 and 2025, E&Y provided no other services to William Blair or any of its control affiliates that were for engagements directly related to the Registrant's operations and financial reporting.

(e) Audit Committee Pre-Approval Policies and Procedures

Pursuant to the Registrant's Audit Committee Charter (the "Charter"), the Audit Committee is responsible for pre-approving any engagement of the principal accountant to provide non-prohibited services to the Registrant, including the fees and other compensation to be paid to the principal accountant, to the extent required by Rule 2-01(c)(7) of Regulation S-X. Pursuant to the Charter, the Audit Committee is also responsible for pre-approving any engagement of the principal accountant, including the fees and other compensation to be paid to the principal accountant, to provide non-audit services to the Registrant's investment adviser (or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the Registrant), if the engagement relates directly to the operations and financial reporting of the Registrant, to the extent required by Rule 2-01(c)(7) of Regulation S-X. The Chair of the Audit Committee may grant the pre-approval referenced above for non-prohibited and non-audit services. All such delegated pre-approvals will be presented to the Audit Committee no later than the next Audit Committee meeting. None of the Audit-Related and Tax Services billed by E&Y for the fiscal years ended December 31, 2024 and 2025 discussed above were approved by the Audit Committee pursuant to a waiver of these Pre-Approval Policies and Procedures.

(f) Not applicable to this Registrant.

(g) Non-Audit Fees

For the fiscal years ended December 31, 2024 and 2025, E&Y billed the Trust $167,135 and $270,015, respectively, in non-audit fees (tax services). For the same periods, E&Y billed the Adviser and its control affiliates $0 and $0, respectively, in non-audit fees.

(h) Not applicable to this Registrant.

(i) Not applicable to this Registrant.

(j) Not applicable to this Registrant.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 5. Audit Committee of Listed Registrants.**

Not applicable to this Registrant, insofar as the Registrant is not a listed company.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 6. Schedule of Investments.**

(a) The complete Schedule of Investments is included in Item 7 of this Form N-CSR.

(b) Not applicable.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 7. Financial Statements and Financial Highlights for Open-End Management Investment Companies.**

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 8. Changes in and Disagreements with Accountants for Open-End Management Investment Companies.**

Not applicable.

------

![](img31fd58351.jpg)

December 31, 2025

William Blair Funds

Annual Financial Statements and Other Information

------

**Table of Contents**

------

---

| | |
|:---|:---|
| **[Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-2_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-2_1)* | 2 |
| **[Large Cap Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-3_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-3_1)* | 4 |
| **[Mid Cap Value Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-4_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-4_1)* | 6 |
| **[Small-Mid Cap Core Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-5_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-5_1)* | 8 |
| **[Small-Mid Cap Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-6_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-6_1)* | 10 |
| **[Small-Mid Cap Value Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-7_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-7_1)* | 12 |
| **[Small Cap Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-8_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-8_1)* | 14 |
| **[Small Cap Value Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-9_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-9_1)* | 16 |
| **[Global Leaders Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-10_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-10_1)* | 18 |
| **[International Leaders Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-11_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-11_1)* | 21 |
| **[International Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-12_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-12_1)* | 24 |
| **[Institutional International Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-13_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-13_1)* | 29 |
| **[International Small Cap Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-14_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-14_1)* | 34 |
| **[Emerging Markets Leaders Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-15_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-15_1)* | 38 |
| **[Emerging Markets Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-16_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-16_1)* | 41 |
| **[Emerging Markets ex China Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-17_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-17_1)* | 45 |
| **[Emerging Markets Small Cap Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-18_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-18_1)* | 49 |
| **[China Growth Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-19_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-19_1)* | 53 |
| **[Emerging Markets Debt Fund](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-20_1)** |  |
| *[Portfolio of Investments](#xx_952197b6-05f0-4030-8944-e5132fb82faa_SOI-TOC-ScheduleofInvestments-20_1)* | 55 |
| **[Financial Statements](#xx_952197b6-05f0-4030-8944-e5132fb82faa_FS-StatementofAssetsandLiabilities_1)** | 64 |
| **[Notes to Financial Statements](#xx_952197b6-05f0-4030-8944-e5132fb82faa_NTF-NotestoFinancialStatements_1)** | 79 |
| **[Financial Highlights](#xx_952197b6-05f0-4030-8944-e5132fb82faa_FIHI-TOC-FinancialHighlights-2_1)** | 99 |
| **[Report of Independent Registered Public Accounting Firm](#xx_952197b6-05f0-4030-8944-e5132fb82faa_AUD-TOC-AuditorsReport-2_1)** | 136 |

---

**This report is submitted for the general information of the shareholders of William Blair Funds. It is not authorized for distribution to prospective Fund investors unless accompanied or preceded by the Fund's prospectus. Please carefully consider a Fund's investment objectives, risks, charges, and expenses before investing. This and other information is contained in the Fund's prospectus, which you may obtain by calling 1-800-742-7272. Read it carefully before you invest or send money.**

*December 31, 2025*

**1**

*William Blair Funds*

------

**Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Information Technology—49.4%** | **Information Technology—49.4%** | **Information Technology—49.4%** |
| \* <br>| Advanced Micro Devices, Inc. | 41438 | &nbsp;&nbsp; $8874 |
| \* <br>| Agilysys, Inc. | 10717 | &nbsp;&nbsp; 1274 |
|  | Apple, Inc. | 53309 | &nbsp;&nbsp; 14493 |
|  | Broadcom, Inc. | 26559 | &nbsp;&nbsp; 9192 |
| \* <br>| Dynatrace, Inc. | 59499 | &nbsp;&nbsp; 2579 |
|  | Intuit, Inc. | 10355 | &nbsp;&nbsp; 6859 |
|  | Microsoft Corp. | 34214 | &nbsp;&nbsp; 16546 |
|  | Motorola Solutions, Inc. | 8482 | &nbsp;&nbsp; 3251 |
|  | NVIDIA Corp. | 137681 | &nbsp;&nbsp; 25677 |
|  | Oracle Corporation | 26404 | &nbsp;&nbsp; 5146 |
| \* <br>| PDF Solutions, Inc. | 63569 | &nbsp;&nbsp; 1814 |
| \* <br>| Pure Storage, Inc. | 44218 | &nbsp;&nbsp; 2963 |
| \* <br>| Q2 Holdings, Inc. | 25564 | &nbsp;&nbsp; 1845 |
| \* <br>| ServiceNow, Inc. | 39618 | &nbsp;&nbsp; 6069 |
| \* <br>| Snowflake Inc. | 18005 | &nbsp;&nbsp; 3950 |
| \* <br>| Tyler Technologies, Inc. | 4864 | &nbsp;&nbsp; 2208 |
|  |  |  | &nbsp;&nbsp; 112740 |
|  | **Health Care—10.4%** | **Health Care—10.4%** | **Health Care—10.4%** |
|  | Abbott Laboratories | 21011 | &nbsp;&nbsp; 2633 |
|  | Agilent Technologies, Inc. | 43146 | &nbsp;&nbsp; 5871 |
| \* <br>| Doximity, Inc. | 31807 | &nbsp;&nbsp; 1408 |
| \* <br>| HealthEquity, Inc. | 13041 | &nbsp;&nbsp; 1195 |
| \* <br>| IDEXX Laboratories, Inc. | 3812 | &nbsp;&nbsp; 2579 |
| \* <br>| Inspire Medical Systems, Inc. | 11782 | &nbsp;&nbsp; 1087 |
| \* <br>| Twist Bioscience Corp. | 36199 | &nbsp;&nbsp; 1148 |
|  | UnitedHealth Group, Inc. | 14051 | &nbsp;&nbsp; 4638 |
|  | West Pharmaceutical Services, Inc. | 11668 | &nbsp;&nbsp; 3210 |
|  |  |  | &nbsp;&nbsp; 23769 |
|  | **Communication Services—9.0%** | **Communication Services—9.0%** | **Communication Services—9.0%** |
|  | Alphabet, Inc.—Class A | 35491 | &nbsp;&nbsp; 11108 |
|  | Meta Platforms, Inc. | 14337 | &nbsp;&nbsp; 9464 |
|  |  |  | &nbsp;&nbsp; 20572 |
|  | **Financials—8.5%** | **Financials—8.5%** | **Financials—8.5%** |
| \* <br>| Baldwin Insurance Group, Inc. | 63750 | &nbsp;&nbsp; 1532 |
|  | Blue Owl Capital Inc. | 87187 | &nbsp;&nbsp; 1303 |
|  | Carlyle Group, Inc. | 67715 | &nbsp;&nbsp; 4003 |
|  | Evercore Inc. | 7030 | &nbsp;&nbsp; 2392 |
|  | Mastercard, Inc. | 17917 | &nbsp;&nbsp; 10228 |
|  |  |  | &nbsp;&nbsp; 19458 |
|  | **Consumer Discretionary—7.0%** | **Consumer Discretionary—7.0%** | **Consumer Discretionary—7.0%** |
| \* <br>| Amazon.com, Inc. | 43437 | &nbsp;&nbsp; 10026 |
| \* <br>| Champion Homes, Inc. | 19672 | &nbsp;&nbsp; 1662 |
| \* <br>| Chipotle Mexican Grill, Inc. | 77892 | &nbsp;&nbsp; 2882 |
| \* <br>| Rush Street Interactive, Inc. | 72808 | &nbsp;&nbsp; 1415 |
|  |  |  | &nbsp;&nbsp; 15985 |
|  | **Industrials—6.5%** | **Industrials—6.5%** | **Industrials—6.5%** |
| \* <br>| ACV Auctions, Inc. | 151775 | &nbsp;&nbsp; 1217 |
|  | C.H. Robinson Worldwide, Inc. | 6993 | &nbsp;&nbsp; 1124 |
| \* <br>| Copart, Inc. | 69179 | &nbsp;&nbsp; 2709 |
|  | Hammond Power Solutions Inc.<sup>†</sup> | 10451 | &nbsp;&nbsp; 1208 |
|  | Lincoln Electric Holdings, Inc. | 5569 | &nbsp;&nbsp; 1335 |
| \* <br>| Modine Manufacturing Co. | 13303 | &nbsp;&nbsp; 1776 |
|  | Mueller Industries, Inc. | 15530 | &nbsp;&nbsp; 1783 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Industrials—(continued)** | **Industrials—(continued)** | **Industrials—(continued)** |
|  | Regal Rexnord Corp. | 8219 | &nbsp;&nbsp; $1153 |
|  | TransUnion | 29641 | &nbsp;&nbsp; 2542 |
|  |  |  | &nbsp;&nbsp; 14847 |
|  | **Consumer Staples—4.8%** | **Consumer Staples—4.8%** | **Consumer Staples—4.8%** |
| \* <br>| e.l.f. Beauty, Inc. | 10788 | &nbsp;&nbsp; 820 |
|  | Primo Brands Corporation | 78890 | &nbsp;&nbsp; 1290 |
| \* <br>| The Simply Good Foods Company | 57512 | &nbsp;&nbsp; 1155 |
|  | Walmart, Inc. | 67833 | &nbsp;&nbsp; 7557 |
|  |  |  | &nbsp;&nbsp; 10822 |
|  | **Energy—2.0%** | **Energy—2.0%** | **Energy—2.0%** |
|  | Cameco Corp.<sup>†</sup> | 50826 | &nbsp;&nbsp; 4650 |
|  | **Materials—0.8%** | **Materials—0.8%** | **Materials—0.8%** |
|  | Quaker Chemical Corporation | 13655 | &nbsp;&nbsp; 1875 |
|  | **Total Common Stocks—98.4%** <br>(cost $158,760)<br>|  | &nbsp;&nbsp; 224718 |

---

---

| | | |
|:---|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $3,703, collateralized by <br> U.S. Treasury Bond, 4.625%, due <br> 11/15/2055, valued at $3,777<br>| $3703 | &nbsp;&nbsp; 3703 |
| **Total Repurchase Agreements—1.6%** <br>(cost $3,703)<br>|  | &nbsp;&nbsp; 3703 |
| **Total Investments—100.0%** <br>(cost $162,463)<br>|  | &nbsp;&nbsp; 228421 |
| **Liabilities, plus cash and** <br>**other assets—(0.0)%**<br>|  | &nbsp;&nbsp; (56)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $228365 |

---

------

\* Non-income producing security <br> † U.S. listed foreign security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**2**

*Annual*

------

**Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $224718 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $224718 |
| Repurchase Agreements |  | &nbsp;&nbsp; 3703 | &nbsp;&nbsp; — | &nbsp;&nbsp; 3703 |
| **Total Investments in Securities** | $224718 | &nbsp;&nbsp; $3703 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $228421 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**3**

*William Blair Funds*

------

**Large Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Information Technology—51.5%** | **Information Technology—51.5%** | **Information Technology—51.5%** |
| \* <br>| Advanced Micro Devices, Inc. | 222930 | &nbsp;&nbsp; $47743 |
|  | Apple, Inc. | 991880 | &nbsp;&nbsp; 269651 |
|  | Broadcom, Inc. | 359710 | &nbsp;&nbsp; 124496 |
|  | Intuit, Inc. | 73090 | &nbsp;&nbsp; 48416 |
|  | Microsoft Corp. | 640560 | &nbsp;&nbsp; 309788 |
|  | NVIDIA Corp. | 1948760 | &nbsp;&nbsp; 363444 |
|  | Oracle Corporation | 219540 | &nbsp;&nbsp; 42790 |
| \* <br>| ServiceNow, Inc. | 364020 | &nbsp;&nbsp; 55764 |
| \* <br>| Snowflake Inc. | 234490 | &nbsp;&nbsp; 51438 |
| \* <br>| Tyler Technologies, Inc. | 87479 | &nbsp;&nbsp; 39711 |
|  |  |  | &nbsp;&nbsp; 1353241 |
|  | **Communication Services—11.3%** | **Communication Services—11.3%** | **Communication Services—11.3%** |
|  | Alphabet, Inc.—Class A | 546870 | &nbsp;&nbsp; 171170 |
|  | Meta Platforms, Inc. | 189130 | &nbsp;&nbsp; 124843 |
|  |  |  | &nbsp;&nbsp; 296013 |
|  | **Consumer Discretionary—10.2%** | **Consumer Discretionary—10.2%** | **Consumer Discretionary—10.2%** |
| \* <br>| Amazon.com, Inc. | 784190 | &nbsp;&nbsp; 181007 |
| \* <br>| Cava Group Inc. | 262100 | &nbsp;&nbsp; 15383 |
| \* <br>| Chipotle Mexican Grill, Inc. | 570010 | &nbsp;&nbsp; 21090 |
| \* <br>| O'Reilly Automotive, Inc. | 555060 | &nbsp;&nbsp; 50627 |
|  |  |  | &nbsp;&nbsp; 268107 |
|  | **Health Care—7.2%** | **Health Care—7.2%** | **Health Care—7.2%** |
|  | Agilent Technologies, Inc. | 377840 | &nbsp;&nbsp; 51413 |
| \* <br>| IDEXX Laboratories, Inc. | 80420 | &nbsp;&nbsp; 54406 |
|  | UnitedHealth Group, Inc. | 142225 | &nbsp;&nbsp; 46950 |
| \* <br>| Veeva Systems, Inc. | 162770 | &nbsp;&nbsp; 36335 |
|  |  |  | &nbsp;&nbsp; 189104 |
|  | **Financials—6.5%** | **Financials—6.5%** | **Financials—6.5%** |
|  | Blue Owl Capital Inc. | 1384960 | &nbsp;&nbsp; 20692 |
|  | Carlyle Group, Inc. | 741297 | &nbsp;&nbsp; 43818 |
|  | Mastercard, Inc. | 188220 | &nbsp;&nbsp; 107451 |
|  |  |  | &nbsp;&nbsp; 171961 |
|  | **Consumer Staples—4.0%** | **Consumer Staples—4.0%** | **Consumer Staples—4.0%** |
|  | Costco Wholesale Corp. | 61230 | &nbsp;&nbsp; 52801 |
| \* <br>| Monster Beverage Corp. | 701790 | &nbsp;&nbsp; 53806 |
|  |  |  | &nbsp;&nbsp; 106607 |
|  | **Industrials—3.9%** | **Industrials—3.9%** | **Industrials—3.9%** |
|  | C.H. Robinson Worldwide, Inc. | 78730 | &nbsp;&nbsp; 12657 |
| \* <br>| Copart, Inc. | 817490 | &nbsp;&nbsp; 32005 |
|  | TransUnion | 488740 | &nbsp;&nbsp; 41909 |
|  | Verisk Analytics, Inc. | 71960 | &nbsp;&nbsp; 16097 |
|  |  |  | &nbsp;&nbsp; 102668 |
|  | **Materials—2.7%** | **Materials—2.7%** | **Materials—2.7%** |
|  | Linde PLC<sup>†</sup> | 93690 | &nbsp;&nbsp; 39948 |
|  | Martin Marietta Materials, Inc. | 50510 | &nbsp;&nbsp; 31451 |
|  |  |  | &nbsp;&nbsp; 71399 |
|  | **Total Common Stocks—97.3%** <br>(cost $1,778,329)<br>|  | &nbsp;&nbsp; 2559100 |
|  | ***Exchange-Traded Funds*** | ***Exchange-Traded Funds*** | ***Exchange-Traded Funds*** |
|  | **Exchange-Traded Funds—2.0%** |  |  |
|  | iShares Russell 1000 Growth ETF | 111040 | &nbsp;&nbsp; 52555 |
|  | **Total Exchange-Traded Funds—2.0%** <br>(cost $52,962)<br>|  | &nbsp;&nbsp; 52555 |

---

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, <br> 1.150% dated 12/31/25, due 01/02/26, <br> repurchase price $19,140, collateralized <br> by U.S. Treasury Bond, 4.625%, due <br> 11/15/2055, valued at $19,521<br>| $19139 | &nbsp;&nbsp; $19139 |
| **Total Repurchase Agreements—0.7%** <br>(cost $19,139)<br>|  | &nbsp;&nbsp; 19139 |
| **Total Investments—100.0%** <br>(cost $1,850,430)<br>|  | &nbsp;&nbsp; 2630794 |
| **Liabilities, plus cash and** <br>**other assets—(0.0)%**<br>|  | &nbsp;&nbsp; (1065)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $2629729 |

---

------

ETF Exchange-Traded Fund <br> PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**4**

*Annual*

------

**Large Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $2559100 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $2559100 |
| Exchange-Traded Funds | 52555 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 52555 |
| Repurchase Agreements |  | &nbsp;&nbsp; 19139 | &nbsp;&nbsp; — | &nbsp;&nbsp; 19139 |
| **Total Investments in Securities** | $2611655 | &nbsp;&nbsp; $19139 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $2630794 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**5**

*William Blair Funds*

------

**Mid Cap Value Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Industrials—20.2%** | **Industrials—20.2%** | **Industrials—20.2%** |
| \* <br>| Alaska Air Group, Inc. | 519 | &nbsp;&nbsp; $26 |
|  | Allegion PLC<sup>†</sup> | 175 | &nbsp;&nbsp; 28 |
|  | Allison Transmission Holdings, Inc. | 238 | &nbsp;&nbsp; 23 |
| \* <br>| CACI International, Inc. | 47 | &nbsp;&nbsp; 25 |
|  | Donaldson Company, Inc. | 329 | &nbsp;&nbsp; 29 |
|  | Dover Corporation | 145 | &nbsp;&nbsp; 28 |
|  | Genpact Ltd. | 526 | &nbsp;&nbsp; 25 |
|  | JB Hunt Transport Services, Inc. | 86 | &nbsp;&nbsp; 17 |
| \* <br>| Kirby Corporation | 290 | &nbsp;&nbsp; 32 |
|  | Knight-Swift Transportation Holdings, Inc. | 285 | &nbsp;&nbsp; 15 |
|  | Timken Co. | 301 | &nbsp;&nbsp; 25 |
|  |  |  | &nbsp;&nbsp; 273 |
|  | **Financials—19.3%** | **Financials—19.3%** | **Financials—19.3%** |
| \* <br>| Arch Capital Group Ltd.<sup>†</sup> | 247 | &nbsp;&nbsp; 24 |
|  | Carlyle Group, Inc. | 391 | &nbsp;&nbsp; 23 |
|  | East West Bancorp, Inc. | 230 | &nbsp;&nbsp; 26 |
|  | Everest Group Ltd. | 77 | &nbsp;&nbsp; 26 |
|  | Hartford Financial Services Group, Inc. | 175 | &nbsp;&nbsp; 24 |
|  | Huntington Bancshares, Inc. | 1531 | &nbsp;&nbsp; 27 |
|  | KKR & Co., Inc. | 215 | &nbsp;&nbsp; 27 |
|  | State Street Corporation | 245 | &nbsp;&nbsp; 32 |
| \* <br>| WEX, Inc. | 162 | &nbsp;&nbsp; 24 |
|  | Willis Towers Watson PLC<sup>†</sup> | 85 | &nbsp;&nbsp; 28 |
|  |  |  | &nbsp;&nbsp; 261 |
|  | **Information Technology—9.8%** | **Information Technology—9.8%** | **Information Technology—9.8%** |
| \* <br>| Check Point Software Technologies Ltd.<sup>†</sup> | 120 | &nbsp;&nbsp; 22 |
|  | Cognizant Technology Solutions Corp. | 205 | &nbsp;&nbsp; 17 |
| \* <br>| Flex Ltd. | 386 | &nbsp;&nbsp; 23 |
|  | Hewlett Packard Enterprise Co. | 1102 | &nbsp;&nbsp; 27 |
|  | Jabil, Inc. | 85 | &nbsp;&nbsp; 20 |
|  | STMicroelectronics N.V.<sup>†</sup> | 931 | &nbsp;&nbsp; 24 |
|  |  |  | &nbsp;&nbsp; 133 |
|  | **Health Care—9.4%** | **Health Care—9.4%** | **Health Care—9.4%** |
|  | Cencora, Inc. | 83 | &nbsp;&nbsp; 28 |
|  | Encompass Health Corp. | 212 | &nbsp;&nbsp; 22 |
| \* <br>| Globus Medical, Inc. | 415 | &nbsp;&nbsp; 36 |
| \* <br>| ICON PLC<sup>†</sup> | 138 | &nbsp;&nbsp; 25 |
|  | Labcorp Holdings, Inc. | 66 | &nbsp;&nbsp; 17 |
|  |  |  | &nbsp;&nbsp; 128 |
|  | **Materials—9.3%** | **Materials—9.3%** | **Materials—9.3%** |
| \* <br>| Axalta Coating Systems Ltd. | 828 | &nbsp;&nbsp; 27 |
|  | CRH PLC | 219 | &nbsp;&nbsp; 27 |
|  | Crown Holdings, Inc. | 211 | &nbsp;&nbsp; 22 |
|  | International Paper Company | 475 | &nbsp;&nbsp; 19 |
|  | Royal Gold, Inc. | 141 | &nbsp;&nbsp; 31 |
|  |  |  | &nbsp;&nbsp; 126 |
|  | **Real Estate—7.8%** | **Real Estate—7.8%** | **Real Estate—7.8%** |
|  | Camden Property Trust | 150 | &nbsp;&nbsp; 16 |
|  | Healthpeak Properties, Inc. | 1104 | &nbsp;&nbsp; 18 |
|  | Host Hotels & Resorts, Inc. | 1203 | &nbsp;&nbsp; 21 |
|  | Regency Centers Corp. | 370 | &nbsp;&nbsp; 26 |
|  | VICI Properties, Inc. | 848 | &nbsp;&nbsp; 24 |
|  |  |  | &nbsp;&nbsp; 105 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Utilities—5.9%** | **Utilities—5.9%** | **Utilities—5.9%** |
|  | Entergy Corp. | 311 | &nbsp;&nbsp; $29 |
|  | NiSource, Inc. | 579 | &nbsp;&nbsp; 24 |
|  | PPL Corp. | 760 | &nbsp;&nbsp; 27 |
|  |  |  | &nbsp;&nbsp; 80 |
|  | **Consumer Staples—5.3%** | **Consumer Staples—5.3%** | **Consumer Staples—5.3%** |
|  | Ingredion, Inc. | 136 | &nbsp;&nbsp; 15 |
|  | Molson Coors Beverage Co. | 405 | &nbsp;&nbsp; 19 |
|  | Tyson Foods, Inc. | 254 | &nbsp;&nbsp; 15 |
| \* <br>| U.S. Foods Holding Corp. | 308 | &nbsp;&nbsp; 23 |
|  |  |  | &nbsp;&nbsp; 72 |
|  | **Energy—5.2%** | **Energy—5.2%** | **Energy—5.2%** |
|  | Coterra Energy, Inc. | 358 | &nbsp;&nbsp; 9 |
|  | Diamondback Energy, Inc. | 81 | &nbsp;&nbsp; 12 |
|  | Expand Energy Corporation | 160 | &nbsp;&nbsp; 18 |
|  | Permian Resources Corp. | 647 | &nbsp;&nbsp; 9 |
|  | Phillips 66 | 171 | &nbsp;&nbsp; 22 |
|  |  |  | &nbsp;&nbsp; 70 |
|  | **Consumer Discretionary—4.6%** | **Consumer Discretionary—4.6%** | **Consumer Discretionary—4.6%** |
|  | Brunswick Corp. | 271 | &nbsp;&nbsp; 20 |
|  | LKQ Corp. | 428 | &nbsp;&nbsp; 13 |
|  | Toll Brothers, Inc. | 217 | &nbsp;&nbsp; 29 |
|  |  |  | &nbsp;&nbsp; 62 |
|  | **Total Common Stocks—96.8%** <br>(cost $1,060)<br>|  | &nbsp;&nbsp; 1310 |
|  | **Total Investments—96.8%** <br>(cost $1,060)<br>|  | &nbsp;&nbsp; 1310 |
|  | **Cash and other assets,** <br>**less liabilities—3.2%**<br>|  | &nbsp;&nbsp; 43 |
|  | **Net Assets—100.0%** |  | &nbsp;&nbsp; $1353 |

---

------

PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**6**

*Annual*

------

**Mid Cap Value Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $1310 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1310 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**7**

*William Blair Funds*

------

**Small-Mid Cap Core Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Industrials—24.9%** | **Industrials—24.9%** | **Industrials—24.9%** |
| \* <br>| ACV Auctions, Inc. | 97253 | &nbsp;&nbsp; $780 |
|  | Applied Industrial Technologies, Inc. | 6143 | &nbsp;&nbsp; 1577 |
|  | Brink's Co. | 8722 | &nbsp;&nbsp; 1018 |
|  | BWX Technologies, Inc. | 9479 | &nbsp;&nbsp; 1638 |
| \* <br>| CACI International, Inc. | 3463 | &nbsp;&nbsp; 1845 |
|  | Carpenter Technology Corporation | 4739 | &nbsp;&nbsp; 1492 |
| \* <br>| Casella Waste Systems, Inc. | 12643 | &nbsp;&nbsp; 1238 |
|  | Curtiss-Wright Corporation | 3228 | &nbsp;&nbsp; 1780 |
|  | Donaldson Company, Inc. | 17587 | &nbsp;&nbsp; 1559 |
| \* <br>| Dycom Industries, Inc. | 3512 | &nbsp;&nbsp; 1187 |
| \* <br>| ExlService Holdings, Inc. | 20808 | &nbsp;&nbsp; 883 |
|  | Flowserve Corp. | 22563 | &nbsp;&nbsp; 1566 |
| \* <br>| GXO Logistics, Inc. | 27572 | &nbsp;&nbsp; 1451 |
|  | JBT Marel Corp | 12029 | &nbsp;&nbsp; 1812 |
|  | Lincoln Electric Holdings, Inc. | 6102 | &nbsp;&nbsp; 1462 |
| \* <br>| Mercury Systems, Inc. | 17261 | &nbsp;&nbsp; 1260 |
|  | Mueller Industries, Inc. | 12460 | &nbsp;&nbsp; 1430 |
|  | nVent Electric PLC<sup>†</sup> | 10155 | &nbsp;&nbsp; 1036 |
|  | Owens Corning | 7474 | &nbsp;&nbsp; 837 |
|  | Tecnoglass, Inc. | 11849 | &nbsp;&nbsp; 596 |
|  | TransUnion | 20362 | &nbsp;&nbsp; 1746 |
|  | UL Solutions Inc. | 16770 | &nbsp;&nbsp; 1323 |
| \* <br>| Verra Mobility Corp. | 50375 | &nbsp;&nbsp; 1129 |
|  |  |  | &nbsp;&nbsp; 30645 |
|  | **Information Technology—15.4%** | **Information Technology—15.4%** | **Information Technology—15.4%** |
| \* <br>| Agilysys, Inc. | 10831 | &nbsp;&nbsp; 1287 |
|  | Bentley Systems, Incorporated | 21728 | &nbsp;&nbsp; 829 |
| \* <br>| Ciena Corporation | 10244 | &nbsp;&nbsp; 2396 |
| \* <br>| Clearwater Analytics Holdings, Inc. | 37640 | &nbsp;&nbsp; 908 |
| \* <br>| Coherent Corp. | 8600 | &nbsp;&nbsp; 1587 |
| \* <br>| Descartes Systems Group, Inc.<sup>†</sup> | 9171 | &nbsp;&nbsp; 804 |
| \* <br>| Diebold Nixdorf, Inc. | 40717 | &nbsp;&nbsp; 2764 |
| \* <br>| Dynatrace, Inc. | 32914 | &nbsp;&nbsp; 1427 |
| \* <br>| F5, Inc. | 6197 | &nbsp;&nbsp; 1582 |
| \* <br>| Onto Innovation, Inc. | 13728 | &nbsp;&nbsp; 2167 |
| \* <br>| OSI Systems, Inc. | 4218 | &nbsp;&nbsp; 1076 |
| \* <br>| Pure Storage, Inc. | 19047 | &nbsp;&nbsp; 1276 |
| \* <br>| Q2 Holdings, Inc. | 12456 | &nbsp;&nbsp; 899 |
|  |  |  | &nbsp;&nbsp; 19002 |
|  | **Health Care—15.3%** | **Health Care—15.3%** | **Health Care—15.3%** |
| \* <br>| Amicus Therapeutics, Inc. | 68490 | &nbsp;&nbsp; 975 |
|  | Bio-Techne Corp. | 31098 | &nbsp;&nbsp; 1829 |
|  | Chemed Corp. | 3877 | &nbsp;&nbsp; 1659 |
| \* <br>| Doximity, Inc. | 42913 | &nbsp;&nbsp; 1900 |
|  | Embecta Corp. | 69771 | &nbsp;&nbsp; 829 |
|  | Encompass Health Corp. | 9496 | &nbsp;&nbsp; 1008 |
| \* <br>| GeneDx Holdings Corp. | 4957 | &nbsp;&nbsp; 645 |
| \* <br>| Halozyme Therapeutics, Inc. | 16986 | &nbsp;&nbsp; 1143 |
| \* <br>| HealthEquity, Inc. | 16978 | &nbsp;&nbsp; 1555 |
| \* <br>| Integer Holdings Corp. | 20900 | &nbsp;&nbsp; 1639 |
| \* <br>| Merit Medical Systems, Inc. | 17647 | &nbsp;&nbsp; 1555 |
| \* <br>| Twist Bioscience Corp. | 28331 | &nbsp;&nbsp; 899 |
| \* <br>| Vericel Corp. | 45767 | &nbsp;&nbsp; 1648 |
| \* <br>| Waystar Holding Corp. | 48061 | &nbsp;&nbsp; 1574 |
|  |  |  | &nbsp;&nbsp; 18858 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Financials—13.4%** | **Financials—13.4%** | **Financials—13.4%** |
| \* <br>| Baldwin Insurance Group, Inc. | 71200 | &nbsp;&nbsp; $1711 |
|  | Banner Corp. | 29619 | &nbsp;&nbsp; 1856 |
|  | Cadence Bank | 25620 | &nbsp;&nbsp; 1098 |
|  | Carlyle Group, Inc. | 34384 | &nbsp;&nbsp; 2032 |
|  | East West Bancorp, Inc. | 14570 | &nbsp;&nbsp; 1638 |
|  | Everest Group Ltd.<sup>†</sup> | 6870 | &nbsp;&nbsp; 2331 |
|  | Marex Group PLC<sup>†</sup> | 36571 | &nbsp;&nbsp; 1403 |
|  | Old National Bancorp | 93138 | &nbsp;&nbsp; 2078 |
|  | Perella Weinberg Partners | 45320 | &nbsp;&nbsp; 784 |
|  | Western Alliance Bancorp | 19083 | &nbsp;&nbsp; 1604 |
|  |  |  | &nbsp;&nbsp; 16535 |
|  | **Consumer Discretionary—9.0%** | **Consumer Discretionary—9.0%** | **Consumer Discretionary—9.0%** |
| \* <br>| Bright Horizons Family Solutions, Inc. | 9795 | &nbsp;&nbsp; 993 |
| \* <br>| Champion Homes, Inc. | 18113 | &nbsp;&nbsp; 1531 |
|  | Garrett Motion, Inc. | 80606 | &nbsp;&nbsp; 1405 |
| \* <br>| Grand Canyon Education, Inc. | 10005 | &nbsp;&nbsp; 1664 |
| \* <br>| National Vision Holdings, Inc. | 40099 | &nbsp;&nbsp; 1035 |
|  | Pool Corp. | 5840 | &nbsp;&nbsp; 1336 |
| \* <br>| Revolve Group, Inc. | 51284 | &nbsp;&nbsp; 1548 |
| \* <br>| SharkNinja, Inc. | 14188 | &nbsp;&nbsp; 1588 |
|  |  |  | &nbsp;&nbsp; 11100 |
|  | **Real Estate—7.2%** | **Real Estate—7.2%** | **Real Estate—7.2%** |
|  | Agree Realty Corp. | 15909 | &nbsp;&nbsp; 1146 |
|  | Americold Realty Trust, Inc. | 62322 | &nbsp;&nbsp; 801 |
|  | Equity LifeStyle Properties, Inc. | 26906 | &nbsp;&nbsp; 1631 |
|  | Healthcare Realty Trust, Inc. | 97442 | &nbsp;&nbsp; 1652 |
| \* <br>| Jones Lang LaSalle Incorporated | 5974 | &nbsp;&nbsp; 2010 |
|  | Rexford Industrial Realty, Inc. | 42203 | &nbsp;&nbsp; 1634 |
|  |  |  | &nbsp;&nbsp; 8874 |
|  | **Consumer Staples—4.0%** | **Consumer Staples—4.0%** | **Consumer Staples—4.0%** |
| \* <br>| Freshpet, Inc. | 14847 | &nbsp;&nbsp; 905 |
|  | Lancaster Colony Corp. | 4864 | &nbsp;&nbsp; 800 |
| \* <br>| Maplebear Inc. | 25574 | &nbsp;&nbsp; 1150 |
|  | Primo Brands Corporation | 87545 | &nbsp;&nbsp; 1431 |
| \* <br>| The Simply Good Foods Company | 31069 | &nbsp;&nbsp; 624 |
|  |  |  | &nbsp;&nbsp; 4910 |
|  | **Materials—3.8%** | **Materials—3.8%** | **Materials—3.8%** |
|  | Eagle Materials, Inc. | 5502 | &nbsp;&nbsp; 1137 |
|  | Louisiana-Pacific Corp. | 9172 | &nbsp;&nbsp; 741 |
|  | Quaker Chemical Corporation | 9119 | &nbsp;&nbsp; 1252 |
|  | Sylvamo Corp. | 31381 | &nbsp;&nbsp; 1511 |
|  |  |  | &nbsp;&nbsp; 4641 |
|  | **Utilities—3.2%** | **Utilities—3.2%** | **Utilities—3.2%** |
|  | IDACORP, Inc. | 15816 | &nbsp;&nbsp; 2002 |
| \* <br>| Talen Energy Corporation | 5176 | &nbsp;&nbsp; 1940 |
|  |  |  | &nbsp;&nbsp; 3942 |
|  | **Energy—2.7%** | **Energy—2.7%** | **Energy—2.7%** |
| \* <br>| Antero Resources Corp. | 28762 | &nbsp;&nbsp; 991 |
|  | Cameco Corp.<sup>†</sup> | 13981 | &nbsp;&nbsp; 1279 |
|  | Weatherford International PLC | 12859 | &nbsp;&nbsp; 1007 |
|  |  |  | &nbsp;&nbsp; 3277 |
|  | **Total Common Stocks—98.9%** <br>(cost $110,197)<br>|  | &nbsp;&nbsp; 121784 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**8**

*Annual*

------

**Small-Mid Cap Core Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $1,185, collateralized by <br> U.S. Treasury Bond, 4.625%, due <br> 11/15/2055, valued at $1,208<br>| $1184 | &nbsp;&nbsp; $1184 |
| **Total Repurchase Agreements—1.0%** <br>(cost $1,184)<br>|  | &nbsp;&nbsp; 1184 |
| **Total Investments—99.9%** <br>(cost $111,381)<br>|  | &nbsp;&nbsp; 122968 |
| **Cash and other assets,** <br>**less liabilities—0.1%**<br>|  | &nbsp;&nbsp; 161 |
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $123129 |

---

------

PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $121784 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $121784 |
| Repurchase Agreements |  | &nbsp;&nbsp; 1184 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1184 |
| **Total Investments in Securities** | $121784 | &nbsp;&nbsp; $1184 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $122968 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**9**

*William Blair Funds*

------

**Small-Mid Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Health Care—23.8%** | **Health Care—23.8%** | **Health Care—23.8%** |
| \* <br>| Amicus Therapeutics, Inc. | 1383400 | &nbsp;&nbsp; $19700 |
|  | Bio-Techne Corp. | 260100 | &nbsp;&nbsp; 15296 |
|  | Chemed Corp. | 39266 | &nbsp;&nbsp; 16800 |
| \* <br>| Doximity, Inc. | 541052 | &nbsp;&nbsp; 23958 |
|  | Encompass Health Corp. | 106517 | &nbsp;&nbsp; 11306 |
| \* <br>| GeneDx Holdings Corp. | 79718 | &nbsp;&nbsp; 10368 |
| \* <br>| Glaukos Corporation | 124200 | &nbsp;&nbsp; 14023 |
| \* <br>| Globus Medical, Inc. | 304595 | &nbsp;&nbsp; 26594 |
| \* <br>| Halozyme Therapeutics, Inc. | 171500 | &nbsp;&nbsp; 11542 |
| \* <br>| HealthEquity, Inc. | 170600 | &nbsp;&nbsp; 15629 |
| \* <br>| Insmed, Inc. | 185951 | &nbsp;&nbsp; 32363 |
| \* <br>| Inspire Medical Systems, Inc. | 119000 | &nbsp;&nbsp; 10975 |
| \* <br>| Insulet Corp. | 22165 | &nbsp;&nbsp; 6300 |
| \* <br>| Krystal Biotech, Inc. | 34907 | &nbsp;&nbsp; 8606 |
| \* <br>| Madrigal Pharmaceuticals, Inc. | 42000 | &nbsp;&nbsp; 24458 |
| \* <br>| Penumbra, Inc. | 52700 | &nbsp;&nbsp; 16385 |
| \* <br>| Twist Bioscience Corp. | 557273 | &nbsp;&nbsp; 17677 |
| \* <br>| Waystar Holding Corp. | 509885 | &nbsp;&nbsp; 16699 |
|  |  |  | &nbsp;&nbsp; 298679 |
|  | **Information Technology—22.4%** | **Information Technology—22.4%** | **Information Technology—22.4%** |
| \* <br>| AppFolio, Inc. | 72146 | &nbsp;&nbsp; 16785 |
|  | Bentley Systems, Incorporated | 324000 | &nbsp;&nbsp; 12365 |
| \* <br>| Ciena Corporation | 131800 | &nbsp;&nbsp; 30824 |
| \* <br>| Clearwater Analytics Holdings, Inc. | 579369 | &nbsp;&nbsp; 13974 |
| \* <br>| Coherent Corp. | 103600 | &nbsp;&nbsp; 19121 |
| \* <br>| Dynatrace, Inc. | 352686 | &nbsp;&nbsp; 15285 |
| \* <br>| F5, Inc. | 62644 | &nbsp;&nbsp; 15991 |
| \* <br>| Guidewire Software, Inc. | 54555 | &nbsp;&nbsp; 10966 |
| \* <br>| Lattice Semiconductor Corp. | 279385 | &nbsp;&nbsp; 20557 |
| \* <br>| Manhattan Associates, Inc. | 100500 | &nbsp;&nbsp; 17418 |
| \* <br>| Novanta, Inc. | 81054 | &nbsp;&nbsp; 9645 |
| \* <br>| Onto Innovation, Inc. | 175666 | &nbsp;&nbsp; 27731 |
| \* <br>| Pure Storage, Inc. | 453600 | &nbsp;&nbsp; 30396 |
| \* <br>| Q2 Holdings, Inc. | 269400 | &nbsp;&nbsp; 19440 |
|  | Teradyne, Inc. | 104200 | &nbsp;&nbsp; 20169 |
|  |  |  | &nbsp;&nbsp; 280667 |
|  | **Industrials—21.1%** | **Industrials—21.1%** | **Industrials—21.1%** |
| \* <br>| ACV Auctions, Inc. | 773682 | &nbsp;&nbsp; 6205 |
|  | Advanced Drainage Systems, Inc. | 104700 | &nbsp;&nbsp; 15164 |
|  | Brink's Co. | 132238 | &nbsp;&nbsp; 15436 |
|  | BWX Technologies, Inc. | 122849 | &nbsp;&nbsp; 21233 |
|  | Carpenter Technology Corporation | 47400 | &nbsp;&nbsp; 14923 |
| \* <br>| Casella Waste Systems, Inc. | 131261 | &nbsp;&nbsp; 12856 |
| \* <br>| Clean Harbors, Inc. | 51700 | &nbsp;&nbsp; 12123 |
|  | Curtiss-Wright Corporation | 31700 | &nbsp;&nbsp; 17475 |
|  | Donaldson Company, Inc. | 199500 | &nbsp;&nbsp; 17688 |
| \* <br>| ExlService Holdings, Inc. | 322400 | &nbsp;&nbsp; 13683 |
|  | Lincoln Electric Holdings, Inc. | 69900 | &nbsp;&nbsp; 16751 |
|  | Mueller Industries, Inc. | 222200 | &nbsp;&nbsp; 25508 |
| \* <br>| Nextracker Inc. | 154900 | &nbsp;&nbsp; 13493 |
|  | nVent Electric PLC<sup>†</sup> | 173200 | &nbsp;&nbsp; 17661 |
| \* <br>| Parsons Corp. | 237600 | &nbsp;&nbsp; 14684 |
|  | Regal Rexnord Corp. | 80200 | &nbsp;&nbsp; 11254 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Industrials—(continued)** | **Industrials—(continued)** | **Industrials—(continued)** |
|  | TransUnion | 123700 | &nbsp;&nbsp; $10607 |
|  | WillScot Mobile Mini Holdings Corp. | 403100 | &nbsp;&nbsp; 7590 |
|  |  |  | &nbsp;&nbsp; 264334 |
|  | **Financials—9.5%** | **Financials—9.5%** | **Financials—9.5%** |
| \* <br>| Baldwin Insurance Group, Inc. | 656710 | &nbsp;&nbsp; 15781 |
|  | Carlyle Group, Inc. | 345493 | &nbsp;&nbsp; 20422 |
|  | Evercore Inc. | 47300 | &nbsp;&nbsp; 16094 |
|  | Everest Group Ltd.<sup>†</sup> | 64432 | &nbsp;&nbsp; 21865 |
|  | First Horizon Corporation | 812300 | &nbsp;&nbsp; 19414 |
|  | TPG, Inc. | 218424 | &nbsp;&nbsp; 13944 |
|  | Western Alliance Bancorp | 130472 | &nbsp;&nbsp; 10969 |
|  |  |  | &nbsp;&nbsp; 118489 |
|  | **Consumer Discretionary—8.2%** | **Consumer Discretionary—8.2%** | **Consumer Discretionary—8.2%** |
| \* <br>| Bright Horizons Family Solutions, Inc. | 138478 | &nbsp;&nbsp; 14042 |
| \* <br>| Cava Group Inc. | 160700 | &nbsp;&nbsp; 9431 |
|  | Churchill Downs, Inc. | 179500 | &nbsp;&nbsp; 20423 |
| \* <br>| National Vision Holdings, Inc. | 398000 | &nbsp;&nbsp; 10276 |
| \* <br>| Planet Fitness, Inc. | 180000 | &nbsp;&nbsp; 19525 |
|  | Pool Corp. | 59200 | &nbsp;&nbsp; 13542 |
| \* <br>| SharkNinja, Inc. | 139800 | &nbsp;&nbsp; 15644 |
|  |  |  | &nbsp;&nbsp; 102883 |
|  | **Consumer Staples—5.0%** | **Consumer Staples—5.0%** | **Consumer Staples—5.0%** |
| \* <br>| BellRing Brands, Inc. | 339300 | &nbsp;&nbsp; 9070 |
| \* <br>| Freshpet, Inc. | 182979 | &nbsp;&nbsp; 11149 |
|  | Lancaster Colony Corp. | 66716 | &nbsp;&nbsp; 10969 |
| \* <br>| Maplebear Inc. | 251226 | &nbsp;&nbsp; 11300 |
|  | Primo Brands Corporation | 1250143 | &nbsp;&nbsp; 20440 |
|  |  |  | &nbsp;&nbsp; 62928 |
|  | **Materials—2.7%** | **Materials—2.7%** | **Materials—2.7%** |
|  | Eagle Materials, Inc. | 66587 | &nbsp;&nbsp; 13762 |
|  | Louisiana-Pacific Corp. | 94900 | &nbsp;&nbsp; 7664 |
|  | Reliance, Inc. | 42000 | &nbsp;&nbsp; 12133 |
|  |  |  | &nbsp;&nbsp; 33559 |
|  | **Utilities—2.2%** | **Utilities—2.2%** | **Utilities—2.2%** |
| \* <br>| Talen Energy Corporation | 72400 | &nbsp;&nbsp; 27138 |
|  | **Energy—1.7%** | **Energy—1.7%** | **Energy—1.7%** |
|  | Cameco Corp.<sup>†</sup> | 234688 | &nbsp;&nbsp; 21472 |
|  | **Real Estate—1.1%** | **Real Estate—1.1%** | **Real Estate—1.1%** |
|  | FirstService Corp. | 52035 | &nbsp;&nbsp; 8093 |
|  | Landbridge Company LLC | 105097 | &nbsp;&nbsp; 5149 |
|  |  |  | &nbsp;&nbsp; 13242 |
|  | **Total Common Stocks—97.7%** <br>(cost $1,038,528)<br>|  | &nbsp;&nbsp; 1223391 |
|  | ***Rights*** | ***Rights*** | ***Rights*** |
|  | **Health Care—0.0%** | **Health Care—0.0%** | **Health Care—0.0%** |
| \* <br>| Abiomed, Inc. \*\* | 80133 | &nbsp;&nbsp; — |
|  | **Total Rights—0.0%** <br>(cost $82)<br>|  | &nbsp;&nbsp; — |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**10**

*Annual*

------

**Small-Mid Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, <br> 1.150% dated 12/31/25, due 01/02/26, <br> repurchase price $11,639, collateralized <br> by U.S. Treasury Bond, 4.625%, due <br> 11/15/2055, valued at $11,871<br>| $11638 | &nbsp;&nbsp; $11638 |
| **Total Repurchase Agreements—0.9%** <br>(cost $11,638)<br>|  | &nbsp;&nbsp; 11638 |
| **Total Investments—98.6%** <br>(cost $1,050,248)<br>|  | &nbsp;&nbsp; 1235029 |
| **Cash and other assets,** <br>**less liabilities—1.4%**<br>|  | &nbsp;&nbsp; 17922 |
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $1252951 |

---

------

PLC Public Limited Company

---

| | |
|:---|:---|
| \* | Non-income producing security |
| † | U.S. listed foreign security |
| \*\* | Fair valued pursuant to the Fund's Valuation Procedures. This <br> holding represents 0.00% of the Fund's net assets at December 31, <br> 2025.<br>|

---

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $1223391 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1223391 |
| Repurchase Agreements |  | &nbsp;&nbsp; 11638 | &nbsp;&nbsp; — | &nbsp;&nbsp; 11638 |
| Rights |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| **Total Investments in Securities** | $1223391 | &nbsp;&nbsp; $11638 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1235029 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**11**

*William Blair Funds*

------

**Small-Mid Cap Value Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Industrials—28.1%** | **Industrials—28.1%** | **Industrials—28.1%** |
|  | ABM Industries, Inc. | 584 | &nbsp;&nbsp; $25 |
|  | Air Lease Corp. | 443 | &nbsp;&nbsp; 28 |
| \* <br>| Alaska Air Group, Inc. | 865 | &nbsp;&nbsp; 43 |
|  | Albany International Corp. | 770 | &nbsp;&nbsp; 39 |
|  | Allegion PLC<sup>†</sup> | 326 | &nbsp;&nbsp; 52 |
|  | Allison Transmission Holdings, Inc. | 500 | &nbsp;&nbsp; 49 |
|  | Armstrong World Industries, Inc. | 208 | &nbsp;&nbsp; 40 |
|  | Atmus Filtration Technologies Inc. | 1090 | &nbsp;&nbsp; 57 |
| \* <br>| CACI International, Inc. | 67 | &nbsp;&nbsp; 36 |
|  | Donaldson Company, Inc. | 619 | &nbsp;&nbsp; 55 |
|  | Dover Corporation | 248 | &nbsp;&nbsp; 48 |
|  | Genpact Ltd. | 936 | &nbsp;&nbsp; 44 |
| \* <br>| Janus International Group, Inc. | 4144 | &nbsp;&nbsp; 27 |
|  | JB Hunt Transport Services, Inc. | 252 | &nbsp;&nbsp; 49 |
| \* <br>| Kirby Corporation | 469 | &nbsp;&nbsp; 52 |
|  | Knight-Swift Transportation Holdings, Inc. | 675 | &nbsp;&nbsp; 35 |
|  | Korn Ferry | 645 | &nbsp;&nbsp; 43 |
|  | Matson, Inc. | 277 | &nbsp;&nbsp; 34 |
|  | Maximus, Inc. | 493 | &nbsp;&nbsp; 43 |
| \* <br>| Modine Manufacturing Co. | 326 | &nbsp;&nbsp; 43 |
|  | Rush Enterprises, Inc. | 432 | &nbsp;&nbsp; 23 |
|  | Tecnoglass, Inc. | 543 | &nbsp;&nbsp; 27 |
|  | Timken Co. | 496 | &nbsp;&nbsp; 42 |
|  | TriNet Group, Inc. | 638 | &nbsp;&nbsp; 38 |
|  |  |  | &nbsp;&nbsp; 972 |
|  | **Financials—18.7%** | **Financials—18.7%** | **Financials—18.7%** |
|  | American Financial Group, Inc. | 285 | &nbsp;&nbsp; 39 |
|  | Ameris Bancorp | 684 | &nbsp;&nbsp; 51 |
|  | Carlyle Group, Inc. | 997 | &nbsp;&nbsp; 59 |
|  | Columbia Banking System, Inc. | 2119 | &nbsp;&nbsp; 59 |
|  | East West Bancorp, Inc. | 432 | &nbsp;&nbsp; 49 |
|  | Eastern Bankshares, Inc. | 3280 | &nbsp;&nbsp; 60 |
|  | Essent Group Ltd. | 692 | &nbsp;&nbsp; 45 |
|  | Everest Group Ltd.<sup>†</sup> | 139 | &nbsp;&nbsp; 47 |
|  | Selective Insurance Group, Inc. | 554 | &nbsp;&nbsp; 46 |
|  | SouthState Bank Corporation | 633 | &nbsp;&nbsp; 60 |
|  | UMB Financial Corporation | 342 | &nbsp;&nbsp; 39 |
|  | Webster Financial Corp | 744 | &nbsp;&nbsp; 47 |
| \* <br>| WEX, Inc. | 292 | &nbsp;&nbsp; 44 |
|  |  |  | &nbsp;&nbsp; 645 |
|  | **Information Technology—9.1%** | **Information Technology—9.1%** | **Information Technology—9.1%** |
|  | Avnet, Inc. | 853 | &nbsp;&nbsp; 41 |
|  | Belden, Inc. | 336 | &nbsp;&nbsp; 39 |
| \* <br>| Diodes, Inc. | 667 | &nbsp;&nbsp; 33 |
| \* <br>| Flex Ltd. | 949 | &nbsp;&nbsp; 57 |
|  | Jabil, Inc. | 118 | &nbsp;&nbsp; 27 |
| \* <br>| Tower Semiconductor Ltd.<sup>†</sup> | 677 | &nbsp;&nbsp; 80 |
|  | Vishay Intertechnology, Inc. | 2556 | &nbsp;&nbsp; 37 |
|  |  |  | &nbsp;&nbsp; 314 |
|  | **Health Care—8.8%** | **Health Care—8.8%** | **Health Care—8.8%** |
|  | Encompass Health Corp. | 308 | &nbsp;&nbsp; 33 |
| \* <br>| Globus Medical, Inc. | 659 | &nbsp;&nbsp; 57 |
| \* <br>| Haemonetics Corp. | 523 | &nbsp;&nbsp; 42 |
| \* <br>| ICON PLC<sup>†</sup> | 262 | &nbsp;&nbsp; 48 |
| \* <br>| ICU Medical, Inc. | 332 | &nbsp;&nbsp; 47 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Health Care—(continued)** | **Health Care—(continued)** | **Health Care—(continued)** |
|  | Labcorp Holdings, Inc. | 138 | &nbsp;&nbsp; $35 |
| \* <br>| Lantheus Holdings, Inc. | 662 | &nbsp;&nbsp; 44 |
|  |  |  | &nbsp;&nbsp; 306 |
|  | **Real Estate—8.2%** | **Real Estate—8.2%** | **Real Estate—8.2%** |
|  | Camden Property Trust | 258 | &nbsp;&nbsp; 28 |
|  | Elme Communities | 1820 | &nbsp;&nbsp; 32 |
|  | Four Corners Property Trust, Inc. | 1409 | &nbsp;&nbsp; 32 |
|  | Healthpeak Properties, Inc. | 2099 | &nbsp;&nbsp; 34 |
|  | Host Hotels & Resorts, Inc. | 1937 | &nbsp;&nbsp; 34 |
|  | Kite Realty Group Trust | 1616 | &nbsp;&nbsp; 39 |
|  | Regency Centers Corp. | 572 | &nbsp;&nbsp; 39 |
|  | STAG Industrial, Inc. | 1213 | &nbsp;&nbsp; 45 |
|  |  |  | &nbsp;&nbsp; 283 |
|  | **Materials—6.9%** | **Materials—6.9%** | **Materials—6.9%** |
| \* <br>| Axalta Coating Systems Ltd. | 1219 | &nbsp;&nbsp; 39 |
|  | Commercial Metals Co. | 838 | &nbsp;&nbsp; 58 |
|  | Crown Holdings, Inc. | 383 | &nbsp;&nbsp; 40 |
|  | Royal Gold, Inc. | 267 | &nbsp;&nbsp; 59 |
|  | Silgan Holdings, Inc. | 1045 | &nbsp;&nbsp; 42 |
|  |  |  | &nbsp;&nbsp; 238 |
|  | **Consumer Discretionary—5.7%** | **Consumer Discretionary—5.7%** | **Consumer Discretionary—5.7%** |
|  | Brunswick Corp. | 481 | &nbsp;&nbsp; 36 |
| \* <br>| Laureate Education, Inc. | 1335 | &nbsp;&nbsp; 45 |
|  | LKQ Corp. | 825 | &nbsp;&nbsp; 25 |
| \* <br>| Taylor Morrison Home Corp. | 498 | &nbsp;&nbsp; 29 |
| \* <br>| Valvoline Inc. | 1474 | &nbsp;&nbsp; 43 |
|  | Winnebago Industries, Inc. | 445 | &nbsp;&nbsp; 18 |
|  |  |  | &nbsp;&nbsp; 196 |
|  | **Energy—4.6%** | **Energy—4.6%** | **Energy—4.6%** |
|  | Expand Energy Corporation | 332 | &nbsp;&nbsp; 37 |
| \* <br>| Expro Group Holdings NV | 3358 | &nbsp;&nbsp; 45 |
|  | Matador Resources Co. | 623 | &nbsp;&nbsp; 26 |
|  | PBF Energy, Inc. | 1069 | &nbsp;&nbsp; 29 |
|  | Permian Resources Corp. | 1612 | &nbsp;&nbsp; 23 |
|  |  |  | &nbsp;&nbsp; 160 |
|  | **Utilities—3.8%** | **Utilities—3.8%** | **Utilities—3.8%** |
|  | IDACORP, Inc. | 357 | &nbsp;&nbsp; 45 |
|  | NiSource, Inc. | 1070 | &nbsp;&nbsp; 45 |
|  | PPL Corp. | 1151 | &nbsp;&nbsp; 40 |
|  |  |  | &nbsp;&nbsp; 130 |
|  | **Consumer Staples—1.8%** | **Consumer Staples—1.8%** | **Consumer Staples—1.8%** |
|  | Ingredion, Inc. | 242 | &nbsp;&nbsp; 27 |
|  | Molson Coors Beverage Co. | 775 | &nbsp;&nbsp; 36 |
|  |  |  | &nbsp;&nbsp; 63 |
|  | **Communication Services—1.8%** | **Communication Services—1.8%** | **Communication Services—1.8%** |
| \* <br>| CarGurus, Inc. | 947 | &nbsp;&nbsp; 36 |
|  | John Wiley & Sons, Inc. | 884 | &nbsp;&nbsp; 27 |
|  |  |  | &nbsp;&nbsp; 63 |
|  | **Total Common Stocks—97.5%** <br>(cost $3,069)<br>|  | &nbsp;&nbsp; 3370 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**12**

*Annual*

------

**Small-Mid Cap Value Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase price <br> $124, collateralized by U.S. Treasury Bond, <br> 4.625%, due 11/15/2055, valued at $127<br>| $124 | &nbsp;&nbsp; $124 |
| **Total Repurchase Agreements—3.6%** <br>(cost $124)<br>|  | &nbsp;&nbsp; 124 |
| **Total Investments—101.1%** <br>(cost $3,193)<br>|  | &nbsp;&nbsp; 3494 |
| **Liabilities, plus cash and** <br>**other assets—(1.1)%**<br>|  | &nbsp;&nbsp; (37)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $3457 |

---

------

PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $3370 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $3370 |
| Repurchase Agreements |  | &nbsp;&nbsp; 124 | &nbsp;&nbsp; — | &nbsp;&nbsp; 124 |
| **Total Investments in Securities** | $3370 | &nbsp;&nbsp; $124 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $3494 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**13**

*William Blair Funds*

------

**Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Health Care—23.2%** | **Health Care—23.2%** | **Health Care—23.2%** |
| \* <br>| Alignment Healthcare, Inc. | 775198 | &nbsp;&nbsp; $15310 |
| \* <br>| Doximity, Inc. | 283890 | &nbsp;&nbsp; 12571 |
| \* <br>| Establishment Labs Holdings, Inc.<sup>†</sup> | 227340 | &nbsp;&nbsp; 16569 |
| \* <br>| GeneDx Holdings Corp. | 59275 | &nbsp;&nbsp; 7709 |
| \* <br>| Glaukos Corporation | 97910 | &nbsp;&nbsp; 11055 |
| \* <br>| Globus Medical, Inc. | 172533 | &nbsp;&nbsp; 15064 |
| \* <br>| Halozyme Therapeutics, Inc. | 113690 | &nbsp;&nbsp; 7651 |
| \* <br>| HealthEquity, Inc. | 107110 | &nbsp;&nbsp; 9812 |
| \* <br>| Inspire Medical Systems, Inc. | 116968 | &nbsp;&nbsp; 10788 |
| \* <br>| Krystal Biotech, Inc. | 54540 | &nbsp;&nbsp; 13446 |
| \* <br>| Madrigal Pharmaceuticals, Inc. | 26288 | &nbsp;&nbsp; 15309 |
| \* <br>| Merit Medical Systems, Inc. | 161000 | &nbsp;&nbsp; 14191 |
| \* <br>| Mirum Pharmaceuticals, Inc. | 113223 | &nbsp;&nbsp; 8944 |
| \* <br>| Procept BioRobotics Corp. | 139970 | &nbsp;&nbsp; 4404 |
| \* <br>| Quanterix Corporation | 687176 | &nbsp;&nbsp; 4370 |
| \* <br>| Treace Medical Concepts, Inc. | 393892 | &nbsp;&nbsp; 965 |
| \* <br>| Twist Bioscience Corp. | 526304 | &nbsp;&nbsp; 16694 |
|  | U.S. Physical Therapy, Inc. | 124662 | &nbsp;&nbsp; 9735 |
| \* <br>| Veracyte, Inc. | 265613 | &nbsp;&nbsp; 11182 |
| \* <br>| Vericel Corp. | 401814 | &nbsp;&nbsp; 14469 |
| \* <br>| Waystar Holding Corp. | 287537 | &nbsp;&nbsp; 9417 |
|  |  |  | &nbsp;&nbsp; 229655 |
|  | **Information Technology—21.1%** | **Information Technology—21.1%** | **Information Technology—21.1%** |
| \* <br>| Aehr Test Systems | 166683 | &nbsp;&nbsp; 3365 |
| \* <br>| Agilysys, Inc. | 101530 | &nbsp;&nbsp; 12066 |
| \* <br>| AppFolio, Inc. | 55530 | &nbsp;&nbsp; 12919 |
| \* <br>| Clearwater Analytics Holdings, Inc. | 413341 | &nbsp;&nbsp; 9970 |
|  | Cognex Corp. | 354530 | &nbsp;&nbsp; 12756 |
| \* <br>| Diebold Nixdorf, Inc. | 299130 | &nbsp;&nbsp; 20308 |
| \* <br>| i3 Verticals, Inc. | 130778 | &nbsp;&nbsp; 3294 |
| \* <br>| Impinj, Inc. | 71300 | &nbsp;&nbsp; 12407 |
| \* <br>| Lattice Semiconductor Corp. | 97910 | &nbsp;&nbsp; 7204 |
| \* <br>| Lumentum Holdings Inc. | 46990 | &nbsp;&nbsp; 17320 |
| \* <br>| Novanta, Inc. | 119270 | &nbsp;&nbsp; 14192 |
| \* <br>| Onto Innovation, Inc. | 89370 | &nbsp;&nbsp; 14108 |
| \* <br>| OSI Systems, Inc. | 32530 | &nbsp;&nbsp; 8297 |
| \* <br>| PDF Solutions, Inc. | 401876 | &nbsp;&nbsp; 11466 |
| \* <br>| Penguin Solutions, Inc. | 314110 | &nbsp;&nbsp; 6144 |
| \* <br>| Q2 Holdings, Inc. | 195170 | &nbsp;&nbsp; 14083 |
| \* <br>| Rambus Inc. | 106460 | &nbsp;&nbsp; 9783 |
| \* <br>| Vertex, Inc. | 409070 | &nbsp;&nbsp; 8169 |
| \* <br>| Zeta Global Holdings Corp. | 510270 | &nbsp;&nbsp; 10384 |
|  |  |  | &nbsp;&nbsp; 208235 |
|  | **Industrials—19.9%** | **Industrials—19.9%** | **Industrials—19.9%** |
| \* <br>| ACV Auctions, Inc. | 1090400 | &nbsp;&nbsp; 8745 |
| \* <br>| Amprius Technologies, Inc. | 331200 | &nbsp;&nbsp; 2613 |
|  | Argan, Inc. | 21360 | &nbsp;&nbsp; 6693 |
| \* <br>| Bloom Energy Corporation | 120590 | &nbsp;&nbsp; 10478 |
|  | Brink's Co. | 161819 | &nbsp;&nbsp; 18889 |
|  | BWX Technologies, Inc. | 57334 | &nbsp;&nbsp; 9910 |
| \* <br>| Casella Waste Systems, Inc. | 108098 | &nbsp;&nbsp; 10587 |
| \* <br>| CECO Environmental Corp. | 237230 | &nbsp;&nbsp; 14198 |
|  | ESAB Corporation | 69000 | &nbsp;&nbsp; 7709 |
|  | Flowserve Corp. | 181700 | &nbsp;&nbsp; 12606 |
| \* <br>| Graham Corporation | 100210 | &nbsp;&nbsp; 6436 |
|  | Hammond Power Solutions Inc.<sup>†</sup> | 95745 | &nbsp;&nbsp; 11070 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Industrials—(continued)** | **Industrials—(continued)** | **Industrials—(continued)** |
|  | Helios Technologies, Inc. | 197140 | &nbsp;&nbsp; $10545 |
| \* <br>| Mercury Systems, Inc. | 204568 | &nbsp;&nbsp; 14936 |
| \* <br>| Modine Manufacturing Co. | 73600 | &nbsp;&nbsp; 9826 |
| \* <br>| Nextracker Inc. | 116310 | &nbsp;&nbsp; 10132 |
|  | Regal Rexnord Corp. | 71090 | &nbsp;&nbsp; 9975 |
| \* <br>| Sterling Infrastructure, Inc. | 13800 | &nbsp;&nbsp; 4226 |
|  | Tecnoglass, Inc.<sup>†</sup> | 106689 | &nbsp;&nbsp; 5369 |
| \* <br>| Verra Mobility Corp. | 507449 | &nbsp;&nbsp; 11372 |
|  |  |  | &nbsp;&nbsp; 196315 |
|  | **Financials—12.5%** | **Financials—12.5%** | **Financials—12.5%** |
| \* <br>| Baldwin Insurance Group, Inc. | 496501 | &nbsp;&nbsp; 11931 |
|  | Cadence Bank | 306230 | &nbsp;&nbsp; 13119 |
| \* <br>| Donnelley Financial Solutions, Inc. | 174470 | &nbsp;&nbsp; 8146 |
|  | Jefferson Capital, Inc. | 499067 | &nbsp;&nbsp; 11149 |
|  | Marex Group PLC | 326600 | &nbsp;&nbsp; 12528 |
|  | Old National Bancorp | 699530 | &nbsp;&nbsp; 15606 |
|  | OneMain Holdings, Inc. | 147860 | &nbsp;&nbsp; 9988 |
| \* <br>| Paymentus Holdings, Inc. | 171846 | &nbsp;&nbsp; 5429 |
|  | Perella Weinberg Partners | 500515 | &nbsp;&nbsp; 8659 |
|  | StepStone Group, Inc. | 225369 | &nbsp;&nbsp; 14462 |
|  | Western Alliance Bancorp | 143455 | &nbsp;&nbsp; 12060 |
|  |  |  | &nbsp;&nbsp; 123077 |
|  | **Consumer Discretionary—9.5%** | **Consumer Discretionary—9.5%** | **Consumer Discretionary—9.5%** |
| \* <br>| Champion Homes, Inc. | 191029 | &nbsp;&nbsp; 16142 |
|  | Garrett Motion, Inc. | 758669 | &nbsp;&nbsp; 13223 |
| \* <br>| Grand Canyon Education, Inc. | 77081 | &nbsp;&nbsp; 12819 |
| \* <br>| National Vision Holdings, Inc. | 335476 | &nbsp;&nbsp; 8662 |
| \* <br>| Planet Fitness, Inc. | 92990 | &nbsp;&nbsp; 10087 |
| \* <br>| Revolve Group, Inc. | 336027 | &nbsp;&nbsp; 10145 |
| \* <br>| Rush Street Interactive, Inc. | 795800 | &nbsp;&nbsp; 15462 |
|  | Winmark Corp | 17419 | &nbsp;&nbsp; 7054 |
|  |  |  | &nbsp;&nbsp; 93594 |
|  | **Materials—4.5%** | **Materials—4.5%** | **Materials—4.5%** |
|  | Balchem Corp. | 100540 | &nbsp;&nbsp; 15419 |
|  | Hawkins, Inc. | 45340 | &nbsp;&nbsp; 6441 |
|  | Quaker Chemical Corporation | 78987 | &nbsp;&nbsp; 10846 |
|  | U.S. Lime & Minerals, Inc. | 96145 | &nbsp;&nbsp; 11512 |
|  |  |  | &nbsp;&nbsp; 44218 |
|  | **Consumer Staples—3.8%** | **Consumer Staples—3.8%** | **Consumer Staples—3.8%** |
| \* <br>| Freshpet, Inc. | 142060 | &nbsp;&nbsp; 8656 |
|  | Primo Brands Corporation | 757030 | &nbsp;&nbsp; 12377 |
| \* <br>| The Simply Good Foods Company | 428130 | &nbsp;&nbsp; 8597 |
| \* <br>| Vital Farms, Inc. | 267330 | &nbsp;&nbsp; 8539 |
|  |  |  | &nbsp;&nbsp; 38169 |
|  | **Real Estate—2.1%** | **Real Estate—2.1%** | **Real Estate—2.1%** |
|  | Americold Realty Trust, Inc. | 499100 | &nbsp;&nbsp; 6418 |
|  | FirstService Corp. | 90457 | &nbsp;&nbsp; 14068 |
|  |  |  | &nbsp;&nbsp; 20486 |
|  | **Energy—2.0%** | **Energy—2.0%** | **Energy—2.0%** |
| \* <br>| BKV Corporation | 372960 | &nbsp;&nbsp; 10126 |
|  | Weatherford International PLC | 119600 | &nbsp;&nbsp; 9360 |
|  |  |  | &nbsp;&nbsp; 19486 |
|  | **Total Common Stocks—98.6%** <br>(cost $859,399)<br>|  | &nbsp;&nbsp; 973235 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**14**

*Annual*

------

**Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
|  | ***Other Assets*** |  |  |
|  | **Health Care—0.0%** |  |  |
| \* <br>| OmniAb, Inc. 12.50 Earnout (Acquired <br> 11/02/22, Cost $0)\*\*<sup>,</sup>#<br>| 23037 | &nbsp;&nbsp; $— |
| \* <br>| OmniAb, Inc. 15.00 Earnout (Acquired <br> 11/02/22, Cost $0)\*\*<sup>,</sup>#<br>| 23037 | &nbsp;&nbsp; — |
|  | **Total Other Assets—0.0%** <br>(cost $—)<br>|  | &nbsp;&nbsp; — |

---

---

| | | |
|:---|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $14,173, collateralized by <br> U.S. Treasury Inflation – Indexed Bond, <br> 2.125%, due 02/15/2054, valued at <br> $14,455<br>| $14172 | &nbsp;&nbsp; 14172 |
| **Total Repurchase Agreements—1.4%** <br>(cost $14,172)<br>|  | &nbsp;&nbsp; 14172 |
| **Total Investments—100.0%** <br>(cost $873,571)<br>|  | &nbsp;&nbsp; 987407 |
| **Liabilities, plus cash and** <br>**other assets—(0.0)%**<br>|  | &nbsp;&nbsp; (307)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $987100 |

---

------

PLC Public Limited Company

---

| | |
|:---|:---|
| \* | Non-income producing security |
| † | U.S. listed foreign security |
| \*\* | Fair valued pursuant to the Fund's Valuation Procedures. This <br> holding represents 0.00% of the Fund's net assets at December 31, <br> 2025.<br>|
| # | Investment in securities not registered under the Securities Act of <br> 1933 (excluding securities acquired pursuant to Rule 144A and <br> Regulation S). The value of such restricted securities represents <br> 0.00% of the Fund's net assets at December 31, 2025.<br>|

---

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $973235 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $973235 |
| Repurchase Agreements |  | &nbsp;&nbsp; 14172 | &nbsp;&nbsp; — | &nbsp;&nbsp; 14172 |
| Other Assets |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| **Total Investments in Securities** | $973235 | &nbsp;&nbsp; $14172 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $987407 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**15**

*William Blair Funds*

------

**Small Cap Value Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | **Financials—25.8%** | **Financials—25.8%** | **Financials—25.8%** |
|  | Ameris Bancorp | 120491 | &nbsp;&nbsp; $8949 |
|  | Atlantic Union Bankshares Corp. | 373781 | &nbsp;&nbsp; 13194 |
|  | Banc Of California, Inc. | 779913 | &nbsp;&nbsp; 15045 |
|  | Brightsphere Investment Group, Inc. | 85701 | &nbsp;&nbsp; 4028 |
|  | Cadence Bank | 219267 | &nbsp;&nbsp; 9393 |
|  | DigitalBridge Group, Inc. | 626288 | &nbsp;&nbsp; 9607 |
|  | Eastern Bankshares, Inc. | 629912 | &nbsp;&nbsp; 11609 |
|  | Enterprise Financial Services Corp. | 82698 | &nbsp;&nbsp; 4466 |
|  | Essent Group Ltd. | 143341 | &nbsp;&nbsp; 9319 |
|  | FB Financial Corporation | 162449 | &nbsp;&nbsp; 9065 |
|  | First Bancorp | 127475 | &nbsp;&nbsp; 6474 |
|  | First Merchants Corp. | 256584 | &nbsp;&nbsp; 9617 |
|  | Hancock Whitney Corp. | 213384 | &nbsp;&nbsp; 13588 |
|  | Live Oak Bancshares, Inc. | 235598 | &nbsp;&nbsp; 8093 |
|  | Old National Bancorp | 601285 | &nbsp;&nbsp; 13415 |
|  | Perella Weinberg Partners | 484753 | &nbsp;&nbsp; 8386 |
|  | Renasant Corporation | 318669 | &nbsp;&nbsp; 11224 |
|  | Seacoast Banking Corp. of Florida | 431325 | &nbsp;&nbsp; 13552 |
|  | Selective Insurance Group, Inc. | 119227 | &nbsp;&nbsp; 9976 |
|  | Stellar Bancorp, Inc. | 172957 | &nbsp;&nbsp; 5351 |
| \* <br>| Texas Capital Bancshares, Inc. | 157416 | &nbsp;&nbsp; 14252 |
|  | The Hanover Insurance Group, Inc. | 50118 | &nbsp;&nbsp; 9160 |
|  | UMB Financial Corporation | 75344 | &nbsp;&nbsp; 8668 |
|  | WaFd, Inc. | 334931 | &nbsp;&nbsp; 10728 |
|  |  |  | &nbsp;&nbsp; 237159 |
|  | **Industrials—23.4%** | **Industrials—23.4%** | **Industrials—23.4%** |
|  | ABM Industries, Inc. | 157428 | &nbsp;&nbsp; 6659 |
|  | Air Lease Corp. | 46024 | &nbsp;&nbsp; 2956 |
| \* <br>| Alaska Air Group, Inc. | 176861 | &nbsp;&nbsp; 8896 |
|  | Albany International Corp. | 161515 | &nbsp;&nbsp; 8189 |
|  | Armstrong World Industries, Inc. | 40482 | &nbsp;&nbsp; 7736 |
|  | Atmus Filtration Technologies Inc. | 226699 | &nbsp;&nbsp; 11768 |
|  | Brady Corp. | 118343 | &nbsp;&nbsp; 9275 |
| \* <br>| Centuri Holdings, Inc. | 268965 | &nbsp;&nbsp; 6791 |
|  | ESCO Technologies, Inc. | 32776 | &nbsp;&nbsp; 6404 |
|  | Granite Construction, Inc. | 71161 | &nbsp;&nbsp; 8208 |
| \* <br>| Hayward Holdings, Inc. | 612581 | &nbsp;&nbsp; 9464 |
|  | Hub Group, Inc. | 210000 | &nbsp;&nbsp; 8948 |
| \* <br>| Huron Consulting Group, Inc. | 65228 | &nbsp;&nbsp; 11279 |
| \* <br>| Janus International Group, Inc. | 880143 | &nbsp;&nbsp; 5756 |
| \* <br>| Kirby Corporation | 100621 | &nbsp;&nbsp; 11086 |
|  | Knight-Swift Transportation Holdings, Inc. | 180909 | &nbsp;&nbsp; 9458 |
|  | Korn Ferry | 138224 | &nbsp;&nbsp; 9126 |
|  | Matson, Inc. | 53764 | &nbsp;&nbsp; 6643 |
|  | Maximus, Inc. | 104368 | &nbsp;&nbsp; 9009 |
| \* <br>| Modine Manufacturing Co. | 42798 | &nbsp;&nbsp; 5714 |
| \* <br>| Openlane, Inc. | 171542 | &nbsp;&nbsp; 5108 |
|  | Rush Enterprises, Inc. | 76765 | &nbsp;&nbsp; 4141 |
|  | Tecnoglass, Inc. | 116688 | &nbsp;&nbsp; 5872 |
| \* <br>| Thermon Group Holdings, Inc. | 297760 | &nbsp;&nbsp; 11065 |
| \* <br>| Titan Machinery, Inc. | 234047 | &nbsp;&nbsp; 3520 |
|  | TriNet Group, Inc. | 134516 | &nbsp;&nbsp; 7954 |
| \* <br>| V2X, Inc. | 158199 | &nbsp;&nbsp; 8630 |
| \* <br>| Verra Mobility Corp. | 269457 | &nbsp;&nbsp; 6038 |
|  |  |  | &nbsp;&nbsp; 215693 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Information Technology—10.1%** | **Information Technology—10.1%** | **Information Technology—10.1%** |
| \* <br>| ADTRAN Holdings, Inc. | 831272 | &nbsp;&nbsp; $7224 |
|  | Avnet, Inc. | 179288 | &nbsp;&nbsp; 8620 |
|  | Belden, Inc. | 71531 | &nbsp;&nbsp; 8337 |
| \* <br>| Diodes, Inc. | 157411 | &nbsp;&nbsp; 7767 |
| \* <br>| Extreme Networks, Inc. | 497023 | &nbsp;&nbsp; 8275 |
| \* <br>| Knowles Corp. | 414179 | &nbsp;&nbsp; 8876 |
|  | Kulicke & Soffa Industries, Inc. | 212019 | &nbsp;&nbsp; 9660 |
| \* <br>| Sanmina Corp. | 77017 | &nbsp;&nbsp; 11558 |
| \* <br>| Tower Semiconductor Ltd.<sup>†</sup> | 126005 | &nbsp;&nbsp; 14795 |
|  | Vishay Intertechnology, Inc. | 531175 | &nbsp;&nbsp; 7697 |
|  |  |  | &nbsp;&nbsp; 92809 |
|  | **Real Estate—8.5%** | **Real Estate—8.5%** | **Real Estate—8.5%** |
|  | CareTrust REIT, Inc. | 280782 | &nbsp;&nbsp; 10153 |
|  | Elme Communities | 487208 | &nbsp;&nbsp; 8477 |
|  | Empire State Realty Trust, Inc. | 940572 | &nbsp;&nbsp; 6133 |
|  | Four Corners Property Trust, Inc. | 351557 | &nbsp;&nbsp; 8107 |
|  | Kite Realty Group Trust | 427813 | &nbsp;&nbsp; 10255 |
|  | LXP Industrial Trust | 202859 | &nbsp;&nbsp; 10058 |
|  | Netstreit Corp. | 345120 | &nbsp;&nbsp; 6088 |
|  | Sila Realty Trust, Inc. | 328808 | &nbsp;&nbsp; 7664 |
|  | Sunstone Hotel Investors, Inc. | 603538 | &nbsp;&nbsp; 5396 |
|  | UMH Properties, Inc. | 380592 | &nbsp;&nbsp; 6055 |
|  |  |  | &nbsp;&nbsp; 78386 |
|  | **Consumer Discretionary—7.9%** | **Consumer Discretionary—7.9%** | **Consumer Discretionary—7.9%** |
| \* <br>| El Pollo Loco Holdings, Inc. | 106236 | &nbsp;&nbsp; 1111 |
| \* <br>| Laureate Education, Inc. | 322561 | &nbsp;&nbsp; 10861 |
|  | La-Z-Boy, Inc. | 242022 | &nbsp;&nbsp; 9020 |
|  | Steven Madden Ltd. | 220710 | &nbsp;&nbsp; 9190 |
| \* <br>| Taylor Morrison Home Corp. | 131815 | &nbsp;&nbsp; 7760 |
| \* <br>| Tri Pointe Homes, Inc. | 287895 | &nbsp;&nbsp; 9060 |
| \* <br>| Valvoline Inc. | 232285 | &nbsp;&nbsp; 6750 |
|  | Winnebago Industries, Inc. | 124746 | &nbsp;&nbsp; 5055 |
|  | Wyndham Hotels & Resorts, Inc. | 94095 | &nbsp;&nbsp; 7110 |
| \* <br>| YETI Holdings, Inc. | 154553 | &nbsp;&nbsp; 6827 |
|  |  |  | &nbsp;&nbsp; 72744 |
|  | **Health Care—4.8%** | **Health Care—4.8%** | **Health Care—4.8%** |
| \* <br>| ADMA Biologics, Inc. | 299516 | &nbsp;&nbsp; 5463 |
| \* <br>| ANI Pharmaceuticals, Inc. | 106421 | &nbsp;&nbsp; 8401 |
| \* <br>| Haemonetics Corp. | 104782 | &nbsp;&nbsp; 8398 |
| \* <br>| ICU Medical, Inc. | 70188 | &nbsp;&nbsp; 10014 |
| \* <br>| Lantheus Holdings, Inc. | 174355 | &nbsp;&nbsp; 11603 |
|  |  |  | &nbsp;&nbsp; 43879 |
|  | **Materials—4.7%** | **Materials—4.7%** | **Materials—4.7%** |
|  | Commercial Metals Co. | 172001 | &nbsp;&nbsp; 11906 |
| \* <br>| Ecovyst, Inc. | 916470 | &nbsp;&nbsp; 8917 |
|  | Greif, Inc. | 95790 | &nbsp;&nbsp; 6485 |
| \* <br>| IAMGOLD Corporation<sup>†</sup> | 410371 | &nbsp;&nbsp; 6767 |
|  | Silgan Holdings, Inc. | 222449 | &nbsp;&nbsp; 8980 |
|  |  |  | &nbsp;&nbsp; 43055 |
|  | **Energy—4.4%** | **Energy—4.4%** | **Energy—4.4%** |
| \* <br>| Expro Group Holdings NV<sup>†</sup> | 710608 | &nbsp;&nbsp; 9486 |
| \* <br>| Gulfport Energy Corp. | 64518 | &nbsp;&nbsp; 13419 |
| \* <br>| Innovex International, Inc. | 196529 | &nbsp;&nbsp; 4298 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**16**

*Annual*

------

**Small Cap Value Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | **Energy—(continued)** | **Energy—(continued)** | **Energy—(continued)** |
|  | Matador Resources Co. | 138777 | &nbsp;&nbsp; $5890 |
|  | PBF Energy, Inc. | 281805 | &nbsp;&nbsp; 7642 |
|  |  |  | &nbsp;&nbsp; 40735 |
|  | **Utilities—4.0%** | **Utilities—4.0%** | **Utilities—4.0%** |
|  | IDACORP, Inc. | 73807 | &nbsp;&nbsp; 9341 |
|  | Northwest Natural Holding Company | 193212 | &nbsp;&nbsp; 9031 |
|  | Northwestern Energy Group, Inc. | 138604 | &nbsp;&nbsp; 8946 |
|  | Spire, Inc. | 113825 | &nbsp;&nbsp; 9413 |
|  |  |  | &nbsp;&nbsp; 36731 |
|  | **Communication Services—1.7%** | **Communication Services—1.7%** | **Communication Services—1.7%** |
| \* <br>| CarGurus, Inc. | 188979 | &nbsp;&nbsp; 7247 |
|  | John Wiley & Sons, Inc. | 265414 | &nbsp;&nbsp; 8130 |
|  |  |  | &nbsp;&nbsp; 15377 |
|  | **Consumer Staples—0.8%** | **Consumer Staples—0.8%** | **Consumer Staples—0.8%** |
| \* <br>| Central Garden & Pet Co. | 121866 | &nbsp;&nbsp; 3557 |
|  | Edgewell Personal Care Co. | 223170 | &nbsp;&nbsp; 3805 |
|  |  |  | &nbsp;&nbsp; 7362 |
|  | **Total Common Stocks—96.1%** <br>(cost $746,399)<br>|  | &nbsp;&nbsp; 883930 |

---

---

| | | |
|:---|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $35,527, collateralized by <br> U.S. Treasury Inflation – Indexed Bonds, <br> 1.375%, 1.500%, 2.125%, due 02/15/2044, <br> 02/15/2053, 02/15/2054, valued at $36,235<br>| $35525 | &nbsp;&nbsp; 35525 |
| **Total Repurchase Agreements—3.9%** <br>(cost $35,525)<br>|  | &nbsp;&nbsp; 35525 |
| **Total Investments—100.0%** <br>(cost $781,924)<br>|  | &nbsp;&nbsp; 919455 |
| **Cash and other assets,** <br>**less liabilities—0.0%**<br>|  | &nbsp;&nbsp; 1 |
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $919456 |

---

------

REIT Real Estate Investment Trust

\* Non-income producing security <br> † U.S. listed foreign security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $883930 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $883930 |
| Repurchase Agreements |  | &nbsp;&nbsp; 35525 | &nbsp;&nbsp; — | &nbsp;&nbsp; 35525 |
| **Total Investments in Securities** | $883930 | &nbsp;&nbsp; $35525 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $919455 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**17**

*William Blair Funds*

------

**Global Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Western Hemisphere—60.2%*** |  |  |
|  | **United States—60.2%** | **United States—60.2%** | **United States—60.2%** |
|  | Alphabet, Inc.—Class A <br>(Interactive Media & Services)<br>| 3391 | &nbsp;&nbsp; $1062 |
| \* <br>| Amazon.com, Inc. <br>(Broadline Retail)<br>| 3012 | &nbsp;&nbsp; 695 |
|  | Apple, Inc. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 1982 | &nbsp;&nbsp; 539 |
|  | Applied Materials, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 1279 | &nbsp;&nbsp; 329 |
|  | Broadcom, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 1510 | &nbsp;&nbsp; 523 |
|  | Cencora, Inc. <br>(Health Care Providers & Services)<br>| 827 | &nbsp;&nbsp; 279 |
|  | CRH PLC <br>(Construction Materials)<br>| 2308 | &nbsp;&nbsp; 288 |
| \* <br>| DexCom, Inc. <br>(Health Care Equipment & Supplies)<br>| 4158 | &nbsp;&nbsp; 276 |
|  | Eli Lilly & Co. <br>(Pharmaceuticals)<br>| 594 | &nbsp;&nbsp; 638 |
| \* <br>| Figure Technology Solutions, Inc. <br>(Consumer Finance)<br>| 4314 | &nbsp;&nbsp; 176 |
|  | Graco, Inc. <br>(Machinery)<br>| 1928 | &nbsp;&nbsp; 158 |
|  | Intercontinental Exchange, Inc. <br>(Capital Markets)<br>| 1129 | &nbsp;&nbsp; 183 |
|  | Intuit, Inc. <br>(Software)<br>| 396 | &nbsp;&nbsp; 262 |
| \* <br>| Intuitive Surgical, Inc. <br>(Health Care Equipment & Supplies)<br>| 542 | &nbsp;&nbsp; 307 |
|  | JPMorgan Chase & Co. <br>(Banks)<br>| 842 | &nbsp;&nbsp; 271 |
|  | Mastercard, Inc. <br>(Financial Services)<br>| 972 | &nbsp;&nbsp; 555 |
|  | Meta Platforms, Inc. <br>(Interactive Media & Services)<br>| 858 | &nbsp;&nbsp; 566 |
|  | Microsoft Corp. <br>(Software)<br>| 1683 | &nbsp;&nbsp; 814 |
| \* <br>| Netflix, Inc. <br>(Entertainment)<br>| 1679 | &nbsp;&nbsp; 158 |
| \* <br>| Novanta, Inc. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 862 | &nbsp;&nbsp; 103 |
|  | NVIDIA Corp. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 6044 | &nbsp;&nbsp; 1127 |
|  | Progressive Corp. <br>(Insurance)<br>| 1099 | &nbsp;&nbsp; 250 |
| \* <br>| ServiceNow, Inc. <br>(Software)<br>| 1353 | &nbsp;&nbsp; 207 |
|  | TKO Group Holdings, Inc. <br>(Entertainment)<br>| 929 | &nbsp;&nbsp; 194 |
| \* <br>| Uber Technologies, Inc. <br>(Road & Rail)<br>| 1921 | &nbsp;&nbsp; 157 |
|  | UnitedHealth Group, Inc. <br>(Health Care Providers & Services)<br>| 747 | &nbsp;&nbsp; 247 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Western Hemisphere—(continued)*** |  |  |
|  | **United States—(continued)** | **United States—(continued)** | **United States—(continued)** |
| \* <br>| Vertex Pharmaceuticals, Inc. <br>(Biotechnology)<br>| 828 | &nbsp;&nbsp; $375 |
|  | Walmart, Inc. <br>(Consumer Staples Distribution & Retail)<br>| 1168 | &nbsp;&nbsp; 130 |
|  | **Total Western Hemisphere** |  | &nbsp;&nbsp; 10869 |
|  | ***Europe Ex-U.K.—19.8%*** |  |  |
|  | **Austria—1.3%** | **Austria—1.3%** | **Austria—1.3%** |
|  | Erste Group Bank AG <br>(Banks)<br>| 1999 | &nbsp;&nbsp; 242 |
|  | **France—6.5%** | **France—6.5%** | **France—6.5%** |
|  | Airbus SE <br>(Aerospace & Defense)<br>| 1212 | &nbsp;&nbsp; 283 |
|  | Hermes International SCA <br>(Textiles, Apparel & Luxury Goods)<br>| 110 | &nbsp;&nbsp; 274 |
|  | Schneider Electric SE <br>(Electrical Equipment)<br>| 615 | &nbsp;&nbsp; 170 |
|  | TotalEnergies SE <br>(Oil, Gas & Consumable Fuels)<br>| 6706 | &nbsp;&nbsp; 438 |
|  |  |  | &nbsp;&nbsp; 1165 |
|  | **Germany—2.3%** | **Germany—2.3%** | **Germany—2.3%** |
|  | Heidelberg Materials AG <br>(Construction Materials)<br>| 467 | &nbsp;&nbsp; 122 |
|  | MTU Aero Engines AG <br>(Aerospace & Defense)<br>| 317 | &nbsp;&nbsp; 132 |
|  | Rheinmetall AG <br>(Aerospace & Defense)<br>| 86 | &nbsp;&nbsp; 158 |
|  |  |  | &nbsp;&nbsp; 412 |
|  | **Ireland—1.0%** | **Ireland—1.0%** | **Ireland—1.0%** |
|  | Linde PLC<sup>†</sup> <br>(Chemicals)<br>| 421 | &nbsp;&nbsp; 179 |
|  | **Israel—0.5%** | **Israel—0.5%** | **Israel—0.5%** |
| \* <br>| Oddity Tech Ltd <br>(Personal Care Products)<br>| 2428 | &nbsp;&nbsp; 98 |
|  | **Italy—1.1%** | **Italy—1.1%** | **Italy—1.1%** |
|  | Ferrari NV<sup>†</sup> <br>(Automobiles)<br>| 552 | &nbsp;&nbsp; 204 |
|  | **Luxembourg—1.0%** | **Luxembourg—1.0%** | **Luxembourg—1.0%** |
|  | CVC Capital Partners PLC <br>(Capital Markets)<br>| 10330 | &nbsp;&nbsp; 174 |
|  | **Netherlands—1.4%** | **Netherlands—1.4%** | **Netherlands—1.4%** |
| \* <br>| argenx SE—ADR <br>(Biotechnology)<br>| 307 | &nbsp;&nbsp; 258 |
|  | **Spain—3.0%** | **Spain—3.0%** | **Spain—3.0%** |
|  | Banco Bilbao Vizcaya Argentaria S.A. <br>(Banks)<br>| 14213 | &nbsp;&nbsp; 335 |
|  | Iberdrola, S.A. <br>(Electric Utilities)<br>| 9447 | &nbsp;&nbsp; 205 |
|  |  |  | &nbsp;&nbsp; 540 |
|  | **Sweden—0.7%** | **Sweden—0.7%** | **Sweden—0.7%** |
| \* <br>| Spotify Technology S.A. <br>(Entertainment)<br>| 207 | &nbsp;&nbsp; 120 |
|  | **Switzerland—1.0%** | **Switzerland—1.0%** | **Switzerland—1.0%** |
|  | Galderma Group AG <br>(Pharmaceuticals)<br>| 920 | &nbsp;&nbsp; 188 |
|  | **Total Europe Ex-U.K.** |  | &nbsp;&nbsp; 3580 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**18**

*Annual*

------

**Global Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—11.0%*** |  |  |
|  | **China—3.1%** | **China—3.1%** | **China—3.1%** |
|  | Tencent Holdings Ltd. <br>(Interactive Media & Services)<br>| 7200 | &nbsp;&nbsp; $554 |
|  | **India—1.5%** | **India—1.5%** | **India—1.5%** |
|  | HDFC Bank Ltd.—ADR <br>(Banks)<br>| 7708 | &nbsp;&nbsp; 281 |
|  | **Indonesia—1.1%** | **Indonesia—1.1%** | **Indonesia—1.1%** |
| \* <br>| Sea Ltd.—ADR <br>(Entertainment)<br>| 1503 | &nbsp;&nbsp; 192 |
|  | **South Korea—1.7%** | **South Korea—1.7%** | **South Korea—1.7%** |
|  | SK Hynix, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 697 | &nbsp;&nbsp; 315 |
|  | **Taiwan—3.6%** | **Taiwan—3.6%** | **Taiwan—3.6%** |
|  | Taiwan Semiconductor Manufacturing Co. <br> Ltd.—ADR <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 2151 | &nbsp;&nbsp; 654 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 1996 |
|  | ***United Kingdom—6.0%*** |  |  |
|  | 3i Group PLC <br>(Capital Markets)<br>| 4985 | &nbsp;&nbsp; 219 |
|  | BAE Systems PLC <br>(Aerospace & Defense)<br>| 8460 | &nbsp;&nbsp; 196 |
|  | British American Tobacco P.L.C. <br>(Tobacco)<br>| 3917 | &nbsp;&nbsp; 223 |
|  | Experian PLC <br>(Professional Services)<br>| 3611 | &nbsp;&nbsp; 164 |
|  | Halma PLC <br>(Electronic Equipment, Instruments & <br> Components)<br>| 1850 | &nbsp;&nbsp; 88 |
|  | London Stock Exchange Group PLC <br>(Capital Markets)<br>| 1553 | &nbsp;&nbsp; 187 |
|  | **Total United Kingdom** |  | &nbsp;&nbsp; 1077 |
|  | ***Japan—1.5%*** |  |  |
|  | Hitachi, Ltd. <br>(Industrial Conglomerates)<br>| 5000 | &nbsp;&nbsp; 156 |
|  | Sumitomo Mitsui Financial Group, Inc. <br>(Banks)<br>| 3500 | &nbsp;&nbsp; 113 |
|  | **Total Japan** |  | &nbsp;&nbsp; 269 |
|  | ***Asia Ex-Japan—0.4%*** |  |  |
|  | **Australia—0.4%** | **Australia—0.4%** | **Australia—0.4%** |
|  | Pro Medicus Ltd. <br>(Health Care Technology)<br>| 536 | &nbsp;&nbsp; 79 |
|  | **Total Common Stocks—98.9%** <br>(cost $14,868)<br>|  | &nbsp;&nbsp; 17870 |
|  | **Total Investments—98.9%** <br>(cost $14,868)<br>|  | &nbsp;&nbsp; 17870 |
|  | **Cash and other assets,** <br>**less liabilities—1.1%**<br>|  | &nbsp;&nbsp; 191 |
|  | **Net Assets—100.0%** |  | &nbsp;&nbsp; $18061 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**19**

*William Blair Funds*

------

**Global Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $17870 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $17870 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**20**

*Annual*

------

**International Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Europe Ex-U.K.—32.8%*** |  |  |
|  | **Belgium—1.7%** | **Belgium—1.7%** | **Belgium—1.7%** |
|  | UCB SA <br>(Pharmaceuticals)<br>| 66271 | &nbsp;&nbsp; $18583 |
|  | **France—3.0%** | **France—3.0%** | **France—3.0%** |
|  | Safran SA <br>(Aerospace & Defense)<br>| 61780 | &nbsp;&nbsp; 21593 |
|  | Vinci SA <br>(Construction & Engineering)<br>| 80536 | &nbsp;&nbsp; 11362 |
|  |  |  | &nbsp;&nbsp; 32955 |
|  | **Germany—4.9%** | **Germany—4.9%** | **Germany—4.9%** |
|  | Heidelberg Materials AG <br>(Construction Materials)<br>| 104695 | &nbsp;&nbsp; 27437 |
|  | Rheinmetall AG <br>(Aerospace & Defense)<br>| 8283 | &nbsp;&nbsp; 15195 |
|  | SAP SE <br>(Software)<br>| 47241 | &nbsp;&nbsp; 11567 |
|  |  |  | &nbsp;&nbsp; 54199 |
|  | **Italy—6.8%** | **Italy—6.8%** | **Italy—6.8%** |
|  | Enel SpA <br>(Electric Utilities)<br>| 2265588 | &nbsp;&nbsp; 23635 |
|  | Ferrari NV<sup>†</sup> <br>(Automobiles)<br>| 26932 | &nbsp;&nbsp; 9953 |
|  | Prysmian S.p.A. <br>(Electrical Equipment)<br>| 224666 | &nbsp;&nbsp; 22807 |
|  | UniCredit S.p.A. <br>(Banks)<br>| 216322 | &nbsp;&nbsp; 18029 |
|  |  |  | &nbsp;&nbsp; 74424 |
|  | **Netherlands—3.6%** | **Netherlands—3.6%** | **Netherlands—3.6%** |
| \* <br>| argenx SE—ADR <br>(Biotechnology)<br>| 17395 | &nbsp;&nbsp; 14629 |
|  | ASML Holding NV <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 22677 | &nbsp;&nbsp; 24555 |
|  |  |  | &nbsp;&nbsp; 39184 |
|  | **Spain—4.7%** | **Spain—4.7%** | **Spain—4.7%** |
|  | Banco Bilbao Vizcaya Argentaria S.A. <br>(Banks)<br>| 1207285 | &nbsp;&nbsp; 28447 |
|  | Iberdrola, S.A. <br>(Electric Utilities)<br>| 1059875 | &nbsp;&nbsp; 22999 |
|  |  |  | &nbsp;&nbsp; 51446 |
|  | **Sweden—0.8%** | **Sweden—0.8%** | **Sweden—0.8%** |
| \* <br>| Spotify Technology S.A. <br>(Entertainment)<br>| 15842 | &nbsp;&nbsp; 9200 |
|  | **Switzerland—7.3%** | **Switzerland—7.3%** | **Switzerland—7.3%** |
|  | ABB Ltd. <br>(Electrical Equipment)<br>| 253008 | &nbsp;&nbsp; 18916 |
|  | Galderma Group AG <br>(Pharmaceuticals)<br>| 75178 | &nbsp;&nbsp; 15385 |
|  | Lonza Group AG <br>(Life Sciences Tools & Services)<br>| 23834 | &nbsp;&nbsp; 16182 |
|  | Sandoz Group AG <br>(Pharmaceuticals)<br>| 396396 | &nbsp;&nbsp; 28945 |
|  |  |  | &nbsp;&nbsp; 79428 |
|  | **Total Europe Ex-U.K.** |  | &nbsp;&nbsp; 359419 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—29.0%*** |  |  |
|  | **China—5.7%** | **China—5.7%** | **China—5.7%** |
|  | NetEase, Inc. <br>(Entertainment)<br>| 349800 | &nbsp;&nbsp; $9645 |
|  | Tencent Holdings Ltd. <br>(Interactive Media & Services)<br>| 457900 | &nbsp;&nbsp; 35243 |
|  | Trip.com Group Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 242300 | &nbsp;&nbsp; 17248 |
|  |  |  | &nbsp;&nbsp; 62136 |
|  | **India—4.3%** | **India—4.3%** | **India—4.3%** |
|  | Bharat Electronics Ltd. <br>(Aerospace & Defense)<br>| 2995136 | &nbsp;&nbsp; 13303 |
|  | Bharti Airtel Ltd. <br>(Wireless Telecommunication <br> Services)<br>| 850535 | &nbsp;&nbsp; 19939 |
|  | ICICI Bank Ltd. <br>(Banks)<br>| 930325 | &nbsp;&nbsp; 13901 |
|  |  |  | &nbsp;&nbsp; 47143 |
|  | **Indonesia—1.6%** | **Indonesia—1.6%** | **Indonesia—1.6%** |
| \* <br>| Sea Ltd.—ADR <br>(Entertainment)<br>| 138641 | &nbsp;&nbsp; 17686 |
|  | **South Korea—7.4%** | **South Korea—7.4%** | **South Korea—7.4%** |
|  | Samsung Electronics Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 448854 | &nbsp;&nbsp; 37359 |
|  | SK Hynix, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 96000 | &nbsp;&nbsp; 43383 |
|  |  |  | &nbsp;&nbsp; 80742 |
|  | **Taiwan—10.0%** | **Taiwan—10.0%** | **Taiwan—10.0%** |
|  | Accton Technology Corp. <br>(Communications Equipment)<br>| 525000 | &nbsp;&nbsp; 19800 |
|  | Hon Hai Precision Industry Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 4819000 | &nbsp;&nbsp; 35352 |
|  | Taiwan Semiconductor Manufacturing <br> Co. Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 1114000 | &nbsp;&nbsp; 54955 |
|  |  |  | &nbsp;&nbsp; 110107 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 317814 |
|  | ***Japan—11.4%*** |  |  |
|  | ASICS Corporation <br>(Textiles, Apparel & Luxury Goods)<br>| 630000 | &nbsp;&nbsp; 15102 |
|  | Fujikura Ltd. <br>(Electrical Equipment)<br>| 217500 | &nbsp;&nbsp; 24216 |
|  | Hitachi, Ltd. <br>(Industrial Conglomerates)<br>| 768300 | &nbsp;&nbsp; 24044 |
|  | IHI Corporation <br>(Machinery)<br>| 1332400 | &nbsp;&nbsp; 23430 |
|  | NEC Corporation <br>(IT Services)<br>| 447200 | &nbsp;&nbsp; 15160 |
|  | Sumitomo Mitsui Financial Group, Inc. <br>(Banks)<br>| 704400 | &nbsp;&nbsp; 22669 |
|  | **Total Japan** |  | &nbsp;&nbsp; 124621 |
|  | ***United Kingdom—11.2%*** |  |  |
|  | 3i Group PLC <br>(Capital Markets)<br>| 433033 | &nbsp;&nbsp; 19046 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**21**

*William Blair Funds*

------

**International Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***United Kingdom—(continued)*** |  |  |
|  | AstraZeneca PLC <br>(Pharmaceuticals)<br>| 128522 | &nbsp;&nbsp; $23890 |
|  | BAE Systems PLC <br>(Aerospace & Defense)<br>| 680713 | &nbsp;&nbsp; 15727 |
|  | Barclays PLC <br>(Banks)<br>| 4027599 | &nbsp;&nbsp; 25839 |
|  | Diploma PLC <br>(Trading Companies & Distributors)<br>| 110617 | &nbsp;&nbsp; 7895 |
|  | Halma PLC <br>(Electronic Equipment, Instruments & <br> Components)<br>| 363248 | &nbsp;&nbsp; 17324 |
|  | London Stock Exchange Group PLC <br>(Capital Markets)<br>| 107773 | &nbsp;&nbsp; 13005 |
|  | **Total United Kingdom** |  | &nbsp;&nbsp; 122726 |
|  | ***Western Hemisphere—6.1%*** |  |  |
|  | **Canada—6.1%** | **Canada—6.1%** | **Canada—6.1%** |
|  | Brookfield Asset Management Ltd. <br>(Capital Markets)<br>| 253612 | &nbsp;&nbsp; 13287 |
|  | Dollarama, Inc. <br>(Broadline Retail)<br>| 133972 | &nbsp;&nbsp; 20023 |
|  | Intact Financial Corp. <br>(Insurance)<br>| 95854 | &nbsp;&nbsp; 19955 |
|  | Lundin Gold Inc. <br>(Metals & Mining)<br>| 160624 | &nbsp;&nbsp; 13343 |
|  | **Total Western Hemisphere** |  | &nbsp;&nbsp; 66608 |
|  | ***Asia Ex-Japan—5.0%*** |  |  |
|  | **Australia—0.4%** | **Australia—0.4%** | **Australia—0.4%** |
|  | Pro Medicus Ltd. <br>(Health Care Technology)<br>| 29801 | &nbsp;&nbsp; 4393 |
|  | **Hong Kong—3.6%** | **Hong Kong—3.6%** | **Hong Kong—3.6%** |
|  | AIA Group Ltd. <br>(Insurance)<br>| 2175200 | &nbsp;&nbsp; 22331 |
|  | Hong Kong Exchanges & Clearing Ltd. <br>(Capital Markets)<br>| 332400 | &nbsp;&nbsp; 17409 |
|  |  |  | &nbsp;&nbsp; 39740 |
|  | **Singapore—1.0%** | **Singapore—1.0%** | **Singapore—1.0%** |
|  | Singapore Telecommunications Limited <br>(Diversified Telecommunication <br> Services)<br>| 2951700 | &nbsp;&nbsp; 10448 |
|  | **Total Asia Ex-Japan** |  | &nbsp;&nbsp; 54581 |
|  | ***Emerging Latin America—4.7%*** |  |  |
|  | **Brazil—3.1%** | **Brazil—3.1%** | **Brazil—3.1%** |
| \* <br>| MercadoLibre, Inc. <br>(Broadline Retail)<br>| 7719 | &nbsp;&nbsp; 15548 |
| \* <br>| NU Holdings Ltd. <br>(Banks)<br>| 1098845 | &nbsp;&nbsp; 18395 |
|  |  |  | &nbsp;&nbsp; 33943 |
|  | **Chile—0.5%** | **Chile—0.5%** | **Chile—0.5%** |
|  | Antofagasta PLC <br>(Metals & Mining)<br>| 128178 | &nbsp;&nbsp; 5665 |
|  | **Peru—1.1%** | **Peru—1.1%** | **Peru—1.1%** |
|  | Credicorp Ltd. <br>(Banks)<br>| 41293 | &nbsp;&nbsp; 11851 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 51459 |

---

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
| ***Emerging Europe, Mid-East,*** <br> ***Africa—0.9%*** |  |  |
| **United Arab Emirates—0.9%** | **United Arab Emirates—0.9%** | **United Arab Emirates—0.9%** |
| Emaar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 2725479 | &nbsp;&nbsp; $10426 |
| **Total Common Stocks—101.1%** <br>(cost $849,578)<br>|  | &nbsp;&nbsp; 1107654 |

---

---

| | | |
|:---|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, <br> 1.150% dated 12/31/25, due 01/02/26, <br> repurchase price $3,125, collateralized <br> by U.S. Treasury Bond, 4.625%, due <br> 11/15/2055, valued at $3,187<br>| $3124 | &nbsp;&nbsp; 3124 |
| **Total Repurchase Agreements—0.3%** <br>(cost $3,124)<br>|  | &nbsp;&nbsp; 3124 |
| **Total Investments—101.4%** <br>(cost $852,702)<br>|  | &nbsp;&nbsp; 1110778 |
| **Liabilities, plus cash and** <br>**other assets—(1.4)%**<br>|  | &nbsp;&nbsp; (15457)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $1095321 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company

† U.S. listed foreign security <br> \* Non-income producing security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**22**

*Annual*

------

**International Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $1107654 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1107654 |
| Repurchase Agreements |  | &nbsp;&nbsp; 3124 | &nbsp;&nbsp; — | &nbsp;&nbsp; 3124 |
| **Total Investments in Securities** | $1107654 | &nbsp;&nbsp; $3124 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1110778 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**23**

*William Blair Funds*

------

**International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
| ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
| ***Europe Ex-U.K.—36.3%*** |  |  |
| **Austria—1.3%** | **Austria—1.3%** | **Austria—1.3%** |
| BAWAG Group AG <br>(Banks)<br>| 35498 | &nbsp;&nbsp; $5382 |
| Erste Group Bank AG <br>(Banks)<br>| 77884 | &nbsp;&nbsp; 9418 |
|  |  | &nbsp;&nbsp; 14800 |
| **Belgium—1.0%** | **Belgium—1.0%** | **Belgium—1.0%** |
| D'ieteren Group <br>(Distributors)<br>| 11503 | &nbsp;&nbsp; 2081 |
| UCB SA <br>(Pharmaceuticals)<br>| 30183 | &nbsp;&nbsp; 8463 |
|  |  | &nbsp;&nbsp; 10544 |
| **Denmark—1.3%** | **Denmark—1.3%** | **Denmark—1.3%** |
| DSV AS <br>(Air Freight & Logistics)<br>| 40611 | &nbsp;&nbsp; 10319 |
| Novonesis Novozymes B <br>(Chemicals)<br>| 70815 | &nbsp;&nbsp; 4544 |
|  |  | &nbsp;&nbsp; 14863 |
| **Finland—0.6%** | **Finland—0.6%** | **Finland—0.6%** |
| Metso OYJ <br>(Machinery)<br>| 290783 | &nbsp;&nbsp; 5119 |
| Valmet OYJ <br>(Machinery)<br>| 47486 | &nbsp;&nbsp; 1581 |
|  |  | &nbsp;&nbsp; 6700 |
| **France—5.5%** | **France—5.5%** | **France—5.5%** |
| Airbus SE <br>(Aerospace & Defense)<br>| 35390 | &nbsp;&nbsp; 8251 |
| Compagnie de Saint-Gobain <br>(Building Products)<br>| 67261 | &nbsp;&nbsp; 6874 |
| Hermes International SCA <br>(Textiles, Apparel & Luxury Goods)<br>| 3397 | &nbsp;&nbsp; 8471 |
| Legrand <br>(Electrical Equipment)<br>| 50473 | &nbsp;&nbsp; 7548 |
| Safran SA <br>(Aerospace & Defense)<br>| 34803 | &nbsp;&nbsp; 12164 |
| Sartorius Stedim Biotech S.A. <br>(Life Sciences Tools & Services)<br>| 27406 | &nbsp;&nbsp; 6763 |
| Schneider Electric SE <br>(Electrical Equipment)<br>| 33573 | &nbsp;&nbsp; 9268 |
| VusionGroup <br>(Electronic Equipment, Instruments <br> & Components)<br>| 10537 | &nbsp;&nbsp; 2529 |
|  |  | &nbsp;&nbsp; 61868 |
| **Germany—5.3%** | **Germany—5.3%** | **Germany—5.3%** |
| Allianz SE <br>(Insurance)<br>| 19683 | &nbsp;&nbsp; 9033 |
| CTS Eventim AG & Co. KGaA <br>(Entertainment)<br>| 60261 | &nbsp;&nbsp; 5559 |
| flatexDEGIRO AG <br>(Capital Markets)<br>| 63134 | &nbsp;&nbsp; 2726 |
| Heidelberg Materials AG <br>(Construction Materials)<br>| 32941 | &nbsp;&nbsp; 8633 |
| MTU Aero Engines AG <br>(Aerospace & Defense)<br>| 22613 | &nbsp;&nbsp; 9442 |
| RENK Group AG <br>(Machinery)<br>| 35231 | &nbsp;&nbsp; 2220 |
| Rheinmetall AG <br>(Aerospace & Defense)<br>| 2937 | &nbsp;&nbsp; 5388 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Europe Ex-U.K.—(continued)*** |  |  |
|  | **Germany—(continued)** | **Germany—(continued)** | **Germany—(continued)** |
|  | SAP SE <br>(Software)<br>| 41001 | &nbsp;&nbsp; $10039 |
| \* <br>| Siemens Energy AG <br>(Electrical Equipment)<br>| 47186 | &nbsp;&nbsp; 6676 |
|  |  |  | &nbsp;&nbsp; 59716 |
|  | **Ireland—1.9%** | **Ireland—1.9%** | **Ireland—1.9%** |
|  | AIB Group PLC <br>(Banks)<br>| 783437 | &nbsp;&nbsp; 8470 |
|  | Kingspan Group PLC <br>(Building Products)<br>| 68163 | &nbsp;&nbsp; 5940 |
|  | Linde PLC<sup>†</sup> <br>(Chemicals)<br>| 16794 | &nbsp;&nbsp; 7161 |
|  |  |  | &nbsp;&nbsp; 21571 |
|  | **Italy—4.5%** | **Italy—4.5%** | **Italy—4.5%** |
|  | Azimut Holding SpA <br>(Capital Markets)<br>| 84433 | &nbsp;&nbsp; 3546 |
|  | Brunello Cucinelli SpA <br>(Textiles, Apparel & Luxury Goods)<br>| 34325 | &nbsp;&nbsp; 3970 |
|  | Enel SpA <br>(Electric Utilities)<br>| 560895 | &nbsp;&nbsp; 5852 |
|  | Intesa Sanpaolo S.p.A <br>(Banks)<br>| 1506422 | &nbsp;&nbsp; 10482 |
|  | Italgas S.p.A. <br>(Gas Utilities)<br>| 491556 | &nbsp;&nbsp; 5497 |
|  | Lottomatica Group S.p.A. <br>(Hotels, Restaurants & Leisure)<br>| 98466 | &nbsp;&nbsp; 2592 |
|  | Saipem S.p.A. <br>(Energy Equipment & Services)<br>| 994510 | &nbsp;&nbsp; 2834 |
|  | UniCredit S.p.A. <br>(Banks)<br>| 179946 | &nbsp;&nbsp; 14998 |
|  |  |  | &nbsp;&nbsp; 49771 |
|  | **Luxembourg—0.4%** | **Luxembourg—0.4%** | **Luxembourg—0.4%** |
|  | CVC Capital Partners PLC <br>(Capital Markets)<br>| 272389 | &nbsp;&nbsp; 4578 |
|  | **Netherlands—4.8%** | **Netherlands—4.8%** | **Netherlands—4.8%** |
| \* <br>| argenx SE—ADR <br>(Biotechnology)<br>| 10681 | &nbsp;&nbsp; 8982 |
|  | ASM International N.V. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 14180 | &nbsp;&nbsp; 8626 |
|  | ASML Holding NV <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 23480 | &nbsp;&nbsp; 25425 |
|  | BE Semiconductor Industries NV <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 38980 | &nbsp;&nbsp; 6127 |
|  | Euronext NV <br>(Capital Markets)<br>| 31578 | &nbsp;&nbsp; 4750 |
|  |  |  | &nbsp;&nbsp; 53910 |
|  | **Norway—0.4%** | **Norway—0.4%** | **Norway—0.4%** |
|  | Gjensidige Forsikring ASA <br>(Insurance)<br>| 63841 | &nbsp;&nbsp; 1913 |
|  | Telenor ASA <br>(Diversified Telecommunication <br> Services)<br>| 205323 | &nbsp;&nbsp; 2988 |
|  |  |  | &nbsp;&nbsp; 4901 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**24**

*Annual*

------

**International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Europe Ex-U.K.—(continued)*** |  |  |
|  | **Spain—2.9%** | **Spain—2.9%** | **Spain—2.9%** |
|  | Banco Bilbao Vizcaya Argentaria S.A. <br>(Banks)<br>| 610484 | &nbsp;&nbsp; $14385 |
|  | Bankinter SA <br>(Banks)<br>| 297603 | &nbsp;&nbsp; 4951 |
|  | Iberdrola, S.A. <br>(Electric Utilities)<br>| 599193 | &nbsp;&nbsp; 13002 |
|  |  |  | &nbsp;&nbsp; 32338 |
|  | **Sweden—2.2%** | **Sweden—2.2%** | **Sweden—2.2%** |
|  | Atlas Copco AB <br>(Machinery)<br>| 455990 | &nbsp;&nbsp; 8225 |
|  | Beijer Ref AB <br>(Trading Companies & Distributors)<br>| 347839 | &nbsp;&nbsp; 5633 |
|  | Indutrade AB <br>(Machinery)<br>| 76409 | &nbsp;&nbsp; 1995 |
| \* <br>| Spotify Technology S.A. <br>(Entertainment)<br>| 12282 | &nbsp;&nbsp; 7132 |
|  | Sweco AB <br>(Construction & Engineering)<br>| 79177 | &nbsp;&nbsp; 1298 |
|  |  |  | &nbsp;&nbsp; 24283 |
|  | **Switzerland—4.2%** | **Switzerland—4.2%** | **Switzerland—4.2%** |
|  | Galderma Group AG <br>(Pharmaceuticals)<br>| 41558 | &nbsp;&nbsp; 8505 |
|  | Galenica AG <br>(Health Care Providers & Services)<br>| 28705 | &nbsp;&nbsp; 3540 |
|  | Garrett Motion, Inc. <br>(Auto Components)<br>| 209249 | &nbsp;&nbsp; 3647 |
|  | Lonza Group AG <br>(Life Sciences Tools & Services)<br>| 21325 | &nbsp;&nbsp; 14479 |
|  | Sandoz Group AG <br>(Pharmaceuticals)<br>| 152033 | &nbsp;&nbsp; 11102 |
| \* <br>| Sportradar Group AG <br>(Hotels, Restaurants & Leisure)<br>| 71408 | &nbsp;&nbsp; 1697 |
|  | VAT Group AG <br>(Machinery)<br>| 8270 | &nbsp;&nbsp; 4029 |
|  |  |  | &nbsp;&nbsp; 46999 |
|  | **Total Europe Ex-U.K.** |  | &nbsp;&nbsp; 406842 |
|  | ***Emerging Asia—24.7%*** |  |  |
|  | **China—5.5%** | **China—5.5%** | **China—5.5%** |
|  | Airtac International Group <br>(Machinery)<br>| 61713 | &nbsp;&nbsp; 1827 |
|  | Alibaba Group Holding Ltd. <br>(Broadline Retail)<br>| 889200 | &nbsp;&nbsp; 16315 |
|  | Fuyao Glass Industry Group Co. Ltd. <br>(Auto Components)<br>| 336610 | &nbsp;&nbsp; 3125 |
|  | Geely Automobile Holdings Limited <br>(Automobiles)<br>| 2202000 | &nbsp;&nbsp; 5065 |
|  | Tencent Holdings Ltd. <br>(Interactive Media & Services)<br>| 427700 | &nbsp;&nbsp; 32918 |
|  | Tencent Music Entertainment <br> Group—ADR <br>(Entertainment)<br>| 128848 | &nbsp;&nbsp; 2259 |
|  |  |  | &nbsp;&nbsp; 61509 |
|  | **India—5.9%** | **India—5.9%** | **India—5.9%** |
|  | Apollo Hospitals Enterprise Ltd. <br>(Health Care Providers & Services)<br>| 19585 | &nbsp;&nbsp; 1534 |
|  | Bajaj Finance Limited <br>(Consumer Finance)<br>| 480571 | &nbsp;&nbsp; 5275 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **India—(continued)** | **India—(continued)** | **India—(continued)** |
|  | Bharat Electronics Ltd. <br>(Aerospace & Defense)<br>| 746269 | &nbsp;&nbsp; $3315 |
|  | Bharti Airtel Ltd. <br>(Wireless Telecommunication <br> Services)<br>| 419914 | &nbsp;&nbsp; 9844 |
|  | Dixon Technologies India Ltd. <br>(Household Durables)<br>| 13303 | &nbsp;&nbsp; 1785 |
|  | Eicher Motors Limited <br>(Automobiles)<br>| 71262 | &nbsp;&nbsp; 5799 |
|  | HDFC Bank Ltd. <br>(Banks)<br>| 744068 | &nbsp;&nbsp; 8220 |
|  | Hindustan Aeronautics Ltd. <br>(Aerospace & Defense)<br>| 61663 | &nbsp;&nbsp; 3009 |
|  | ICICI Bank Ltd. <br>(Banks)<br>| 516737 | &nbsp;&nbsp; 7721 |
|  | Indian Hotels Co. Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 333635 | &nbsp;&nbsp; 2737 |
|  | Macrotech Developers Ltd. <br>(Real Estate Management & <br> Development)<br>| 154159 | &nbsp;&nbsp; 1820 |
|  | Mahindra & Mahindra Ltd. <br>(Automobiles)<br>| 135562 | &nbsp;&nbsp; 5605 |
|  | Maruti Suzuki India Limited <br>(Automobiles)<br>| 24395 | &nbsp;&nbsp; 4529 |
|  | Max Healthcare Institute Ltd. <br>(Health Care Providers & Services)<br>| 194020 | &nbsp;&nbsp; 2256 |
| \* <br>| Zomato Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 772702 | &nbsp;&nbsp; 2390 |
|  |  |  | &nbsp;&nbsp; 65839 |
|  | **Indonesia—1.1%** | **Indonesia—1.1%** | **Indonesia—1.1%** |
|  | Bank Central Asia Tbk. PT <br>(Banks)<br>| 16275900 | &nbsp;&nbsp; 7882 |
| \* <br>| Grab Holdings Limited <br>(Road & Rail)<br>| 839516 | &nbsp;&nbsp; 4189 |
|  |  |  | &nbsp;&nbsp; 12071 |
|  | **South Korea—4.3%** | **South Korea—4.3%** | **South Korea—4.3%** |
|  | HD Hyundai Co.,Ltd. <br>(Oil, Gas & Consumable Fuels)<br>| 33176 | &nbsp;&nbsp; 4341 |
|  | Samsung Electronics Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 197572 | &nbsp;&nbsp; 16444 |
|  | SK Hynix, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 52478 | &nbsp;&nbsp; 23715 |
| \* <br>| WuXi Biologics (Cayman) Inc. <br>(Life Sciences Tools & Services)<br>| 946000 | &nbsp;&nbsp; 3822 |
|  |  |  | &nbsp;&nbsp; 48322 |
|  | **Taiwan—7.5%** | **Taiwan—7.5%** | **Taiwan—7.5%** |
|  | Accton Technology Corp. <br>(Communications Equipment)<br>| 195000 | &nbsp;&nbsp; 7354 |
|  | Asia Vital Components Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 96000 | &nbsp;&nbsp; 4614 |
|  | Hon Hai Precision Industry Co., Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 2305000 | &nbsp;&nbsp; 16909 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**25**

*William Blair Funds*

------

**International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **Taiwan—(continued)** | **Taiwan—(continued)** | **Taiwan—(continued)** |
|  | King Slide Works Co., Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 22000 | &nbsp;&nbsp; $2626 |
|  | Taiwan Semiconductor Manufacturing <br> Co. Ltd.—ADR <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 174908 | &nbsp;&nbsp; 53153 |
|  |  |  | &nbsp;&nbsp; 84656 |
|  | **Thailand—0.4%** | **Thailand—0.4%** | **Thailand—0.4%** |
| \* <br>| Fabrinet <br>(Electronic Equipment, Instruments <br> & Components)<br>| 10774 | &nbsp;&nbsp; 4905 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 277302 |
|  | ***Japan—11.8%*** |  |  |
|  | Asahi Intecc Co., Ltd. <br>(Health Care Equipment & Supplies)<br>| 144300 | &nbsp;&nbsp; 2706 |
|  | ASICS Corporation <br>(Textiles, Apparel & Luxury Goods)<br>| 229800 | &nbsp;&nbsp; 5509 |
|  | BayCurrent Consulting, Inc. <br>(Professional Services)<br>| 51700 | &nbsp;&nbsp; 2145 |
|  | Bridgestone Corporation <br>(Auto Components)<br>| 188000 | &nbsp;&nbsp; 4218 |
|  | Daifuku Co. Ltd. <br>(Machinery)<br>| 207700 | &nbsp;&nbsp; 6534 |
|  | Disco Corp. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 24100 | &nbsp;&nbsp; 7411 |
|  | Hoya Corp. <br>(Health Care Equipment & Supplies)<br>| 72700 | &nbsp;&nbsp; 10993 |
|  | Ibiden Co., Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 143200 | &nbsp;&nbsp; 6153 |
|  | IHI Corporation <br>(Machinery)<br>| 628600 | &nbsp;&nbsp; 11054 |
|  | Internet Initiative Japan, Inc. <br>(Diversified Telecommunication <br> Services)<br>| 92800 | &nbsp;&nbsp; 1638 |
|  | Japan Elevator Service Holdings Co. <br> Ltd. <br>(Commercial Services & Supplies)<br>| 172600 | &nbsp;&nbsp; 1916 |
|  | Keyence Corp. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 18900 | &nbsp;&nbsp; 6839 |
|  | Kurita Water Industries Ltd. <br>(Machinery)<br>| 45300 | &nbsp;&nbsp; 1836 |
|  | MatsukiyoCocokara & Co. <br>(Consumer Staples Distribution & <br> Retail)<br>| 148500 | &nbsp;&nbsp; 2571 |
|  | MonotaRO Co. Ltd. <br>(Trading Companies & Distributors)<br>| 267600 | &nbsp;&nbsp; 4272 |
|  | NEC Corporation <br>(IT Services)<br>| 164800 | &nbsp;&nbsp; 5587 |
|  | Nomura Research Institute Ltd. <br>(IT Services)<br>| 79000 | &nbsp;&nbsp; 3037 |
|  | Organo Corporation <br>(Machinery)<br>| 26400 | &nbsp;&nbsp; 2183 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Japan—(continued)*** |  |  |
|  | Pan Pacific International Holdings <br> Corp. <br>(Broadline Retail)<br>| 557700 | &nbsp;&nbsp; $3319 |
| \* <br>| Rakuten Bank Ltd. <br>(Banks)<br>| 65200 | &nbsp;&nbsp; 2877 |
|  | Sanwa Holdings Corporation <br>(Building Products)<br>| 115100 | &nbsp;&nbsp; 2997 |
|  | Sumitomo Electric Industries, Ltd. <br>(Auto Components)<br>| 220400 | &nbsp;&nbsp; 8900 |
|  | Sumitomo Mitsui Financial Group, Inc. <br>(Banks)<br>| 431900 | &nbsp;&nbsp; 13899 |
|  | Tokio Marine Holdings, Inc. <br>(Insurance)<br>| 375800 | &nbsp;&nbsp; 13956 |
|  | **Total Japan** |  | &nbsp;&nbsp; 132550 |
|  | ***United Kingdom—11.2%*** |  |  |
|  | 3i Group PLC <br>(Capital Markets)<br>| 200559 | &nbsp;&nbsp; 8821 |
|  | Allfunds Group PLC <br>(Capital Markets)<br>| 306371 | &nbsp;&nbsp; 2897 |
|  | AstraZeneca PLC <br>(Pharmaceuticals)<br>| 110302 | &nbsp;&nbsp; 20503 |
|  | BAE Systems PLC <br>(Aerospace & Defense)<br>| 458948 | &nbsp;&nbsp; 10603 |
|  | Barclays PLC <br>(Banks)<br>| 1591350 | &nbsp;&nbsp; 10209 |
|  | Beazley PLC <br>(Insurance)<br>| 404190 | &nbsp;&nbsp; 4533 |
|  | BT Group PLC <br>(Diversified Telecommunication <br> Services)<br>| 1933063 | &nbsp;&nbsp; 4796 |
|  | Coca-Cola Europacific Partners PLC <br>(Beverages)<br>| 56932 | &nbsp;&nbsp; 5164 |
|  | Compass Group PLC <br>(Hotels, Restaurants & Leisure)<br>| 253197 | &nbsp;&nbsp; 8068 |
|  | Diploma PLC <br>(Trading Companies & Distributors)<br>| 114317 | &nbsp;&nbsp; 8159 |
|  | Halma PLC <br>(Electronic Equipment, Instruments <br> & Components)<br>| 223056 | &nbsp;&nbsp; 10638 |
|  | Hill & Smith PLC <br>(Metals & Mining)<br>| 50050 | &nbsp;&nbsp; 1444 |
|  | London Stock Exchange Group PLC <br>(Capital Markets)<br>| 106346 | &nbsp;&nbsp; 12833 |
|  | Rotork PLC <br>(Machinery)<br>| 618309 | &nbsp;&nbsp; 2712 |
|  | Softcat PLC <br>(IT Services)<br>| 87268 | &nbsp;&nbsp; 1667 |
|  | Spirax-Sarco Engineering PLC <br>(Machinery)<br>| 25282 | &nbsp;&nbsp; 2324 |
|  | Unilever PLC <br>(Personal Care Products)<br>| 99446 | &nbsp;&nbsp; 6514 |
|  | Weir Group PLC <br>(Machinery)<br>| 94375 | &nbsp;&nbsp; 3621 |
|  | **Total United Kingdom** |  | &nbsp;&nbsp; 125506 |
|  | ***Emerging Latin America—4.5%*** |  |  |
|  | **Brazil—3.2%** | **Brazil—3.2%** | **Brazil—3.2%** |
| \* <br>| Banco BTG Pactual SA <br>(Capital Markets)<br>| 825200 | &nbsp;&nbsp; 7918 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**26**

*Annual*

------

**International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Latin*** <br> ***America—(continued)***<br>|  |  |
|  | **Brazil—(continued)** | **Brazil—(continued)** | **Brazil—(continued)** |
|  | Companhia de Saneamento Basico do <br> Estado de Sao Paulo - SABESP <br>(Water Utilities)<br>| 142226 | &nbsp;&nbsp; $3462 |
|  | Embraer S.A. <br>(Aerospace & Defense)<br>| 183600 | &nbsp;&nbsp; 2969 |
|  | Itau Unibanco Holding SA—ADR <br>(Banks)<br>| 994071 | &nbsp;&nbsp; 7117 |
| \* <br>| MercadoLibre, Inc. <br>(Broadline Retail)<br>| 3149 | &nbsp;&nbsp; 6343 |
| \* <br>| NU Holdings Ltd. <br>(Banks)<br>| 364143 | &nbsp;&nbsp; 6096 |
|  | XP Inc. <br>(Capital Markets)<br>| 99756 | &nbsp;&nbsp; 1633 |
|  |  |  | &nbsp;&nbsp; 35538 |
|  | **Chile—0.5%** | **Chile—0.5%** | **Chile—0.5%** |
|  | Antofagasta PLC <br>(Metals & Mining)<br>| 130456 | &nbsp;&nbsp; 5766 |
|  | **Mexico—0.5%** | **Mexico—0.5%** | **Mexico—0.5%** |
|  | Arca Continental S.A.B. de C.V. <br>(Beverages)<br>| 142400 | &nbsp;&nbsp; 1538 |
|  | Grupo Aeroportuario del Centro Norte <br> S.A.B. de C.V. <br>(Transportation Infrastructure)<br>| 129700 | &nbsp;&nbsp; 1761 |
|  | Grupo Aeroportuario del Sureste S.A.B. <br> de C.V.—ADR <br>(Transportation Infrastructure)<br>| 6668 | &nbsp;&nbsp; 2156 |
|  |  |  | &nbsp;&nbsp; 5455 |
|  | **Peru—0.3%** | **Peru—0.3%** | **Peru—0.3%** |
|  | Credicorp Ltd.<sup>†</sup> <br>(Banks)<br>| 11870 | &nbsp;&nbsp; 3407 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 50166 |
|  | ***Western Hemisphere—4.1%*** |  |  |
|  | **Bermuda—0.6%** | **Bermuda—0.6%** | **Bermuda—0.6%** |
| \* <br>| Arch Capital Group Ltd.<sup>†</sup> <br>(Insurance)<br>| 73801 | &nbsp;&nbsp; 7079 |
|  | **Canada—3.5%** | **Canada—3.5%** | **Canada—3.5%** |
|  | Boyd Group Services, Inc. <br>(Commercial Services & Supplies)<br>| 8347 | &nbsp;&nbsp; 1330 |
|  | Intact Financial Corp. <br>(Insurance)<br>| 54436 | &nbsp;&nbsp; 11332 |
| \* <br>| K92 Mining Inc. <br>(Metals & Mining)<br>| 173324 | &nbsp;&nbsp; 2865 |
|  | Lundin Gold Inc. <br>(Metals & Mining)<br>| 100498 | &nbsp;&nbsp; 8348 |
| \* <br>| MDA Space Ltd. <br>(Aerospace & Defense)<br>| 62850 | &nbsp;&nbsp; 1220 |
|  | Toromont Industries Ltd. <br>(Trading Companies & Distributors)<br>| 55362 | &nbsp;&nbsp; 6698 |
|  | WSP Global Inc. <br>(Construction & Engineering)<br>| 40927 | &nbsp;&nbsp; 7410 |
|  |  |  | &nbsp;&nbsp; 39203 |
|  | **Total Western Hemisphere** |  | &nbsp;&nbsp; 46282 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—3.4%*** |  |  |
|  | **South Africa—2.4%** | **South Africa—2.4%** | **South Africa—2.4%** |
|  | Bid Corp. Ltd. <br>(Consumer Staples Distribution & <br> Retail)<br>| 156094 | &nbsp;&nbsp; $3976 |
|  | Capitec Bank Holdings Ltd. <br>(Banks)<br>| 13531 | &nbsp;&nbsp; 3396 |
|  | Clicks Group Ltd. <br>(Consumer Staples Distribution & <br> Retail)<br>| 80182 | &nbsp;&nbsp; 1630 |
|  | FirstRand Limited <br>(Financial Services)<br>| 984840 | &nbsp;&nbsp; 5397 |
|  | Gold Fields Limited <br>(Metals & Mining)<br>| 184591 | &nbsp;&nbsp; 8089 |
|  | MTN Group Limited <br>(Wireless Telecommunication <br> Services)<br>| 402318 | &nbsp;&nbsp; 4118 |
|  |  |  | &nbsp;&nbsp; 26606 |
|  | **United Arab Emirates—1.0%** | **United Arab Emirates—1.0%** | **United Arab Emirates—1.0%** |
|  | Aldar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 674340 | &nbsp;&nbsp; 1597 |
|  | Emaar Development PJSC <br>(Real Estate Management & <br> Development)<br>| 531205 | &nbsp;&nbsp; 2191 |
|  | Emaar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 1062409 | &nbsp;&nbsp; 4064 |
|  | Emirates NBD Bank PJSC <br>(Banks)<br>| 517274 | &nbsp;&nbsp; 3923 |
|  |  |  | &nbsp;&nbsp; 11775 |
|  | **Total Emerging Europe, Mid-East,** <br> **Africa**<br>|  | &nbsp;&nbsp; 38381 |
|  | ***Asia Ex-Japan—2.8%*** |  |  |
|  | **Australia—1.0%** | **Australia—1.0%** | **Australia—1.0%** |
| \* <br>| Capricorn Metals Ltd <br>(Metals & Mining)<br>| 293128 | &nbsp;&nbsp; 2813 |
|  | Pro Medicus Ltd. <br>(Health Care Technology)<br>| 15971 | &nbsp;&nbsp; 2354 |
|  | QBE Insurance Group Limited <br>(Insurance)<br>| 235614 | &nbsp;&nbsp; 3127 |
|  | Steadfast Group Ltd. <br>(Insurance)<br>| 649254 | &nbsp;&nbsp; 2288 |
|  |  |  | &nbsp;&nbsp; 10582 |
|  | **Hong Kong—1.5%** | **Hong Kong—1.5%** | **Hong Kong—1.5%** |
|  | AIA Group Ltd. <br>(Insurance)<br>| 806800 | &nbsp;&nbsp; 8283 |
|  | Hong Kong Exchanges & Clearing Ltd. <br>(Capital Markets)<br>| 158400 | &nbsp;&nbsp; 8296 |
|  |  |  | &nbsp;&nbsp; 16579 |
|  | **Singapore—0.3%** | **Singapore—0.3%** | **Singapore—0.3%** |
|  | DBS Group Holdings Ltd. <br>(Banks)<br>| 85010 | &nbsp;&nbsp; 3727 |
|  | **Total Asia Ex-Japan** |  | &nbsp;&nbsp; 30888 |
|  | **Total Common Stocks—98.8%** <br>(cost $826,932)<br>|  | &nbsp;&nbsp; 1107917 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**27**

*William Blair Funds*

------

**International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, <br> 1.150% dated 12/31/25, due 01/02/26, <br> repurchase price $17,094, <br> collateralized by U.S. Treasury <br> Inflation – Indexed Bond, 1.375%, due <br> 02/15/2044, and U.S. Treasury Bond, <br> 4.750%, due 02/15/2041, valued at <br> $17,435<br>| $17093 | &nbsp;&nbsp; $17093 |
| **Total Repurchase Agreements—1.5%** <br>(cost $17,093)<br>|  | &nbsp;&nbsp; 17093 |
| **Total Investments—100.3%** <br>(cost $844,025)<br>|  | &nbsp;&nbsp; 1125010 |
| **Liabilities, plus cash and** <br>**other assets—(0.3)%**<br>|  | &nbsp;&nbsp; (3785)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $1121225 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $1103012 | &nbsp;&nbsp; $4905 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1107917 |
| Repurchase Agreements |  | &nbsp;&nbsp; 17093 | &nbsp;&nbsp; — | &nbsp;&nbsp; 17093 |
| **Total Investments in Securities** | $1103012 | &nbsp;&nbsp; $21998 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1125010 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**28**

*Annual*

------

**Institutional International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
| ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
| ***Europe Ex-U.K.—36.2%*** |  |  |
| **Austria—1.3%** | **Austria—1.3%** | **Austria—1.3%** |
| BAWAG Group AG <br>(Banks)<br>| 26382 | &nbsp;&nbsp; $3999 |
| Erste Group Bank AG <br>(Banks)<br>| 57884 | &nbsp;&nbsp; 7000 |
|  |  | &nbsp;&nbsp; 10999 |
| **Belgium—1.0%** | **Belgium—1.0%** | **Belgium—1.0%** |
| D'ieteren Group <br>(Distributors)<br>| 8549 | &nbsp;&nbsp; 1546 |
| UCB SA <br>(Pharmaceuticals)<br>| 22432 | &nbsp;&nbsp; 6290 |
|  |  | &nbsp;&nbsp; 7836 |
| **Denmark—1.3%** | **Denmark—1.3%** | **Denmark—1.3%** |
| DSV AS <br>(Air Freight & Logistics)<br>| 30183 | &nbsp;&nbsp; 7670 |
| Novonesis Novozymes B <br>(Chemicals)<br>| 52630 | &nbsp;&nbsp; 3377 |
|  |  | &nbsp;&nbsp; 11047 |
| **Finland—0.6%** | **Finland—0.6%** | **Finland—0.6%** |
| Metso OYJ <br>(Machinery)<br>| 216112 | &nbsp;&nbsp; 3804 |
| Valmet OYJ <br>(Machinery)<br>| 35292 | &nbsp;&nbsp; 1175 |
|  |  | &nbsp;&nbsp; 4979 |
| **France—5.5%** | **France—5.5%** | **France—5.5%** |
| Airbus SE <br>(Aerospace & Defense)<br>| 26302 | &nbsp;&nbsp; 6132 |
| Compagnie de Saint-Gobain <br>(Building Products)<br>| 49989 | &nbsp;&nbsp; 5109 |
| Hermes International SCA <br>(Textiles, Apparel & Luxury Goods)<br>| 2525 | &nbsp;&nbsp; 6297 |
| Legrand <br>(Electrical Equipment)<br>| 37512 | &nbsp;&nbsp; 5610 |
| Safran SA <br>(Aerospace & Defense)<br>| 25866 | &nbsp;&nbsp; 9040 |
| Sartorius Stedim Biotech S.A. <br>(Life Sciences Tools & Services)<br>| 20368 | &nbsp;&nbsp; 5027 |
| Schneider Electric SE <br>(Electrical Equipment)<br>| 24952 | &nbsp;&nbsp; 6888 |
| VusionGroup <br>(Electronic Equipment, Instruments & <br> Components)<br>| 7831 | &nbsp;&nbsp; 1879 |
|  |  | &nbsp;&nbsp; 45982 |
| **Germany—5.3%** | **Germany—5.3%** | **Germany—5.3%** |
| Allianz SE <br>(Insurance)<br>| 14628 | &nbsp;&nbsp; 6713 |
| CTS Eventim AG & Co. KGaA <br>(Entertainment)<br>| 44787 | &nbsp;&nbsp; 4132 |
| flatexDEGIRO AG <br>(Capital Markets)<br>| 46921 | &nbsp;&nbsp; 2026 |
| Heidelberg Materials AG <br>(Construction Materials)<br>| 24482 | &nbsp;&nbsp; 6416 |
| MTU Aero Engines AG <br>(Aerospace & Defense)<br>| 16806 | &nbsp;&nbsp; 7017 |
| RENK Group AG <br>(Machinery)<br>| 26184 | &nbsp;&nbsp; 1650 |
| Rheinmetall AG <br>(Aerospace & Defense)<br>| 2183 | &nbsp;&nbsp; 4005 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Europe Ex-U.K.—(continued)*** |  |  |
|  | **Germany—(continued)** | **Germany—(continued)** | **Germany—(continued)** |
|  | SAP SE <br>(Software)<br>| 30472 | &nbsp;&nbsp; $7461 |
| \* <br>| Siemens Energy AG <br>(Electrical Equipment)<br>| 35069 | &nbsp;&nbsp; 4962 |
|  |  |  | &nbsp;&nbsp; 44382 |
|  | **Ireland—1.9%** | **Ireland—1.9%** | **Ireland—1.9%** |
|  | AIB Group PLC <br>(Banks)<br>| 582258 | &nbsp;&nbsp; 6295 |
|  | Kingspan Group PLC <br>(Building Products)<br>| 50659 | &nbsp;&nbsp; 4415 |
|  | Linde PLC<sup>†</sup> <br>(Chemicals)<br>| 12482 | &nbsp;&nbsp; 5322 |
|  |  |  | &nbsp;&nbsp; 16032 |
|  | **Italy—4.4%** | **Italy—4.4%** | **Italy—4.4%** |
|  | Azimut Holding SpA <br>(Capital Markets)<br>| 62751 | &nbsp;&nbsp; 2636 |
|  | Brunello Cucinelli SpA <br>(Textiles, Apparel & Luxury Goods)<br>| 25510 | &nbsp;&nbsp; 2951 |
|  | Enel SpA <br>(Electric Utilities)<br>| 416862 | &nbsp;&nbsp; 4349 |
|  | Intesa Sanpaolo S.p.A <br>(Banks)<br>| 1119586 | &nbsp;&nbsp; 7791 |
|  | Italgas S.p.A. <br>(Gas Utilities)<br>| 365328 | &nbsp;&nbsp; 4085 |
|  | Lottomatica Group S.p.A. <br>(Hotels, Restaurants & Leisure)<br>| 73181 | &nbsp;&nbsp; 1926 |
|  | Saipem S.p.A. <br>(Energy Equipment & Services)<br>| 739129 | &nbsp;&nbsp; 2106 |
|  | UniCredit S.p.A. <br>(Banks)<br>| 133737 | &nbsp;&nbsp; 11146 |
|  |  |  | &nbsp;&nbsp; 36990 |
|  | **Luxembourg—0.4%** | **Luxembourg—0.4%** | **Luxembourg—0.4%** |
|  | CVC Capital Partners PLC <br>(Capital Markets)<br>| 202442 | &nbsp;&nbsp; 3402 |
|  | **Netherlands—4.8%** | **Netherlands—4.8%** | **Netherlands—4.8%** |
| \* <br>| argenx SE—ADR <br>(Biotechnology)<br>| 7938 | &nbsp;&nbsp; 6676 |
|  | ASM International N.V. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 10538 | &nbsp;&nbsp; 6410 |
|  | ASML Holding NV <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 17450 | &nbsp;&nbsp; 18895 |
|  | BE Semiconductor Industries NV <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 28970 | &nbsp;&nbsp; 4554 |
|  | Euronext NV <br>(Capital Markets)<br>| 23469 | &nbsp;&nbsp; 3530 |
|  |  |  | &nbsp;&nbsp; 40065 |
|  | **Norway—0.4%** | **Norway—0.4%** | **Norway—0.4%** |
|  | Gjensidige Forsikring ASA <br>(Insurance)<br>| 47447 | &nbsp;&nbsp; 1421 |
|  | Telenor ASA <br>(Diversified Telecommunication <br> Services)<br>| 152598 | &nbsp;&nbsp; 2221 |
|  |  |  | &nbsp;&nbsp; 3642 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**29**

*William Blair Funds*

------

**Institutional International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Europe Ex-U.K.—(continued)*** |  |  |
|  | **Spain—2.9%** | **Spain—2.9%** | **Spain—2.9%** |
|  | Banco Bilbao Vizcaya Argentaria S.A. <br>(Banks)<br>| 453717 | &nbsp;&nbsp; $10691 |
|  | Bankinter SA <br>(Banks)<br>| 221181 | &nbsp;&nbsp; 3679 |
|  | Iberdrola, S.A. <br>(Electric Utilities)<br>| 445325 | &nbsp;&nbsp; 9664 |
|  |  |  | &nbsp;&nbsp; 24034 |
|  | **Sweden—2.2%** | **Sweden—2.2%** | **Sweden—2.2%** |
|  | Atlas Copco AB <br>(Machinery)<br>| 338895 | &nbsp;&nbsp; 6112 |
|  | Beijer Ref AB <br>(Trading Companies & Distributors)<br>| 258517 | &nbsp;&nbsp; 4187 |
|  | Indutrade AB <br>(Machinery)<br>| 56788 | &nbsp;&nbsp; 1483 |
| \* <br>| Spotify Technology S.A. <br>(Entertainment)<br>| 9128 | &nbsp;&nbsp; 5301 |
|  | Sweco AB <br>(Construction & Engineering)<br>| 58845 | &nbsp;&nbsp; 964 |
|  |  |  | &nbsp;&nbsp; 18047 |
|  | **Switzerland—4.2%** | **Switzerland—4.2%** | **Switzerland—4.2%** |
|  | Galderma Group AG <br>(Pharmaceuticals)<br>| 30886 | &nbsp;&nbsp; 6321 |
|  | Galenica AG <br>(Health Care Providers & Services)<br>| 21334 | &nbsp;&nbsp; 2631 |
|  | Garrett Motion, Inc. <br>(Auto Components)<br>| 155516 | &nbsp;&nbsp; 2711 |
|  | Lonza Group AG <br>(Life Sciences Tools & Services)<br>| 15849 | &nbsp;&nbsp; 10761 |
|  | Sandoz Group AG <br>(Pharmaceuticals)<br>| 112992 | &nbsp;&nbsp; 8251 |
| \* <br>| Sportradar Group AG <br>(Hotels, Restaurants & Leisure)<br>| 53071 | &nbsp;&nbsp; 1261 |
|  | VAT Group AG <br>(Machinery)<br>| 6146 | &nbsp;&nbsp; 2994 |
|  |  |  | &nbsp;&nbsp; 34930 |
|  | **Total Europe Ex-U.K.** |  | &nbsp;&nbsp; 302367 |
|  | ***Emerging Asia—24.7%*** |  |  |
|  | **China—5.5%** | **China—5.5%** | **China—5.5%** |
|  | Airtac International Group <br>(Machinery)<br>| 46204 | &nbsp;&nbsp; 1368 |
|  | Alibaba Group Holding Ltd. <br>(Broadline Retail)<br>| 660900 | &nbsp;&nbsp; 12126 |
|  | Fuyao Glass Industry Group Co. Ltd. <br>(Auto Components)<br>| 250200 | &nbsp;&nbsp; 2323 |
|  | Geely Automobile Holdings Limited <br>(Automobiles)<br>| 1637000 | &nbsp;&nbsp; 3765 |
|  | Tencent Holdings Ltd. <br>(Interactive Media & Services)<br>| 317900 | &nbsp;&nbsp; 24467 |
|  | Tencent Music Entertainment <br> Group—ADR <br>(Entertainment)<br>| 95761 | &nbsp;&nbsp; 1679 |
|  |  |  | &nbsp;&nbsp; 45728 |
|  | **India—5.9%** | **India—5.9%** | **India—5.9%** |
|  | Apollo Hospitals Enterprise Ltd. <br>(Health Care Providers & Services)<br>| 14556 | &nbsp;&nbsp; 1140 |
|  | Bajaj Finance Limited <br>(Consumer Finance)<br>| 357165 | &nbsp;&nbsp; 3920 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **India—(continued)** | **India—(continued)** | **India—(continued)** |
|  | Bharat Electronics Ltd. <br>(Aerospace & Defense)<br>| 554633 | &nbsp;&nbsp; $2463 |
|  | Bharti Airtel Ltd. <br>(Wireless Telecommunication Services)<br>| 312084 | &nbsp;&nbsp; 7316 |
|  | Dixon Technologies India Ltd. <br>(Household Durables)<br>| 9887 | &nbsp;&nbsp; 1327 |
|  | Eicher Motors Limited <br>(Automobiles)<br>| 52963 | &nbsp;&nbsp; 4310 |
|  | HDFC Bank Ltd. <br>(Banks)<br>| 552998 | &nbsp;&nbsp; 6109 |
|  | Hindustan Aeronautics Ltd. <br>(Aerospace & Defense)<br>| 45829 | &nbsp;&nbsp; 2236 |
|  | ICICI Bank Ltd. <br>(Banks)<br>| 384043 | &nbsp;&nbsp; 5738 |
|  | Indian Hotels Co. Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 247960 | &nbsp;&nbsp; 2035 |
|  | Macrotech Developers Ltd. <br>(Real Estate Management & <br> Development)<br>| 114572 | &nbsp;&nbsp; 1353 |
|  | Mahindra & Mahindra Ltd. <br>(Automobiles)<br>| 100751 | &nbsp;&nbsp; 4165 |
|  | Maruti Suzuki India Limited <br>(Automobiles)<br>| 18130 | &nbsp;&nbsp; 3366 |
|  | Max Healthcare Institute Ltd. <br>(Health Care Providers & Services)<br>| 144198 | &nbsp;&nbsp; 1677 |
| \* <br>| Zomato Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 574279 | &nbsp;&nbsp; 1777 |
|  |  |  | &nbsp;&nbsp; 48932 |
|  | **Indonesia—1.1%** | **Indonesia—1.1%** | **Indonesia—1.1%** |
|  | Bank Central Asia Tbk. PT <br>(Banks)<br>| 12096330 | &nbsp;&nbsp; 5858 |
| \* <br>| Grab Holdings Limited <br>(Road & Rail)<br>| 623936 | &nbsp;&nbsp; 3113 |
|  |  |  | &nbsp;&nbsp; 8971 |
|  | **South Korea—4.3%** | **South Korea—4.3%** | **South Korea—4.3%** |
|  | HD Hyundai Co.,Ltd. <br>(Oil, Gas & Consumable Fuels)<br>| 24657 | &nbsp;&nbsp; 3226 |
|  | Samsung Electronics Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 146837 | &nbsp;&nbsp; 12222 |
|  | SK Hynix, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 39002 | &nbsp;&nbsp; 17625 |
| \* <br>| WuXi Biologics (Cayman) Inc. <br>(Life Sciences Tools & Services)<br>| 703000 | &nbsp;&nbsp; 2840 |
|  |  |  | &nbsp;&nbsp; 35913 |
|  | **Taiwan—7.5%** | **Taiwan—7.5%** | **Taiwan—7.5%** |
|  | Accton Technology Corp. <br>(Communications Equipment)<br>| 145000 | &nbsp;&nbsp; 5469 |
|  | Asia Vital Components Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 72000 | &nbsp;&nbsp; 3460 |
|  | Hon Hai Precision Industry Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 1713000 | &nbsp;&nbsp; 12566 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**30**

*Annual*

------

**Institutional International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **Taiwan—(continued)** | **Taiwan—(continued)** | **Taiwan—(continued)** |
|  | King Slide Works Co., Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 16000 | &nbsp;&nbsp; $1910 |
|  | Taiwan Semiconductor Manufacturing <br> Co. Ltd.—ADR <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 129993 | &nbsp;&nbsp; 39504 |
|  |  |  | &nbsp;&nbsp; 62909 |
|  | **Thailand—0.4%** | **Thailand—0.4%** | **Thailand—0.4%** |
| \* <br>| Fabrinet <br>(Electronic Equipment, Instruments & <br> Components)<br>| 8007 | &nbsp;&nbsp; 3646 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 206099 |
|  | ***Japan—11.8%*** |  |  |
|  | Asahi Intecc Co., Ltd. <br>(Health Care Equipment & Supplies)<br>| 107300 | &nbsp;&nbsp; 2012 |
|  | ASICS Corporation <br>(Textiles, Apparel & Luxury Goods)<br>| 170800 | &nbsp;&nbsp; 4094 |
|  | BayCurrent Consulting, Inc. <br>(Professional Services)<br>| 38400 | &nbsp;&nbsp; 1594 |
|  | Bridgestone Corporation <br>(Auto Components)<br>| 139800 | &nbsp;&nbsp; 3136 |
|  | Daifuku Co. Ltd. <br>(Machinery)<br>| 154400 | &nbsp;&nbsp; 4858 |
|  | Disco Corp. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 17900 | &nbsp;&nbsp; 5505 |
|  | Hoya Corp. <br>(Health Care Equipment & Supplies)<br>| 54000 | &nbsp;&nbsp; 8165 |
|  | Ibiden Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 106400 | &nbsp;&nbsp; 4572 |
|  | IHI Corporation <br>(Machinery)<br>| 467200 | &nbsp;&nbsp; 8216 |
|  | Internet Initiative Japan, Inc. <br>(Diversified Telecommunication <br> Services)<br>| 68900 | &nbsp;&nbsp; 1216 |
|  | Japan Elevator Service Holdings Co. Ltd. <br>(Commercial Services & Supplies)<br>| 128300 | &nbsp;&nbsp; 1424 |
|  | Keyence Corp. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 14100 | &nbsp;&nbsp; 5102 |
|  | Kurita Water Industries Ltd. <br>(Machinery)<br>| 33700 | &nbsp;&nbsp; 1366 |
|  | MatsukiyoCocokara & Co. <br>(Consumer Staples Distribution & <br> Retail)<br>| 110400 | &nbsp;&nbsp; 1911 |
|  | MonotaRO Co. Ltd. <br>(Trading Companies & Distributors)<br>| 198800 | &nbsp;&nbsp; 3174 |
|  | NEC Corporation <br>(IT Services)<br>| 122500 | &nbsp;&nbsp; 4153 |
|  | Nomura Research Institute Ltd. <br>(IT Services)<br>| 58700 | &nbsp;&nbsp; 2256 |
|  | Organo Corporation <br>(Machinery)<br>| 19600 | &nbsp;&nbsp; 1621 |
|  | Pan Pacific International Holdings Corp. <br>(Broadline Retail)<br>| 461300 | &nbsp;&nbsp; 2746 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Japan—(continued)*** |  |  |
| \* <br>| Rakuten Bank Ltd. <br>(Banks)<br>| 48500 | &nbsp;&nbsp; $2140 |
|  | Sanwa Holdings Corporation <br>(Building Products)<br>| 85500 | &nbsp;&nbsp; 2227 |
|  | Sumitomo Electric Industries, Ltd. <br>(Auto Components)<br>| 163800 | &nbsp;&nbsp; 6614 |
|  | Sumitomo Mitsui Financial Group, Inc. <br>(Banks)<br>| 321000 | &nbsp;&nbsp; 10330 |
|  | Tokio Marine Holdings, Inc. <br>(Insurance)<br>| 279300 | &nbsp;&nbsp; 10372 |
|  | **Total Japan** |  | &nbsp;&nbsp; 98804 |
|  | ***United Kingdom—11.2%*** |  |  |
|  | 3i Group PLC <br>(Capital Markets)<br>| 149057 | &nbsp;&nbsp; 6556 |
|  | Allfunds Group PLC <br>(Capital Markets)<br>| 227697 | &nbsp;&nbsp; 2153 |
|  | AstraZeneca PLC <br>(Pharmaceuticals)<br>| 81978 | &nbsp;&nbsp; 15238 |
|  | BAE Systems PLC <br>(Aerospace & Defense)<br>| 341094 | &nbsp;&nbsp; 7881 |
|  | Barclays PLC <br>(Banks)<br>| 1182705 | &nbsp;&nbsp; 7588 |
|  | Beazley PLC <br>(Insurance)<br>| 300398 | &nbsp;&nbsp; 3369 |
|  | BT Group PLC <br>(Diversified Telecommunication <br> Services)<br>| 1436669 | &nbsp;&nbsp; 3564 |
|  | Coca-Cola Europacific Partners PLC <br>(Beverages)<br>| 42312 | &nbsp;&nbsp; 3838 |
|  | Compass Group PLC <br>(Hotels, Restaurants & Leisure)<br>| 188178 | &nbsp;&nbsp; 5996 |
|  | Diploma PLC <br>(Trading Companies & Distributors)<br>| 84961 | &nbsp;&nbsp; 6064 |
|  | Halma PLC <br>(Electronic Equipment, Instruments & <br> Components)<br>| 165777 | &nbsp;&nbsp; 7906 |
|  | Hill & Smith PLC <br>(Metals & Mining)<br>| 37198 | &nbsp;&nbsp; 1073 |
|  | London Stock Exchange Group PLC <br>(Capital Markets)<br>| 79037 | &nbsp;&nbsp; 9537 |
|  | Rotork PLC <br>(Machinery)<br>| 459533 | &nbsp;&nbsp; 2016 |
|  | Softcat PLC <br>(IT Services)<br>| 64858 | &nbsp;&nbsp; 1239 |
|  | Spirax-Sarco Engineering PLC <br>(Machinery)<br>| 18790 | &nbsp;&nbsp; 1727 |
|  | Unilever PLC <br>(Personal Care Products)<br>| 73909 | &nbsp;&nbsp; 4841 |
|  | Weir Group PLC <br>(Machinery)<br>| 70140 | &nbsp;&nbsp; 2691 |
|  | **Total United Kingdom** |  | &nbsp;&nbsp; 93277 |
|  | ***Emerging Latin America—4.5%*** |  |  |
|  | **Brazil—3.2%** | **Brazil—3.2%** | **Brazil—3.2%** |
| \* <br>| Banco BTG Pactual SA <br>(Capital Markets)<br>| 613300 | &nbsp;&nbsp; 5885 |
|  | Companhia de Saneamento Basico do <br> Estado de Sao Paulo - SABESP <br>(Water Utilities)<br>| 116491 | &nbsp;&nbsp; 2836 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**31**

*William Blair Funds*

------

**Institutional International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Latin*** <br> ***America—(continued)***<br>|  |  |
|  | **Brazil—(continued)** | **Brazil—(continued)** | **Brazil—(continued)** |
|  | Embraer S.A. <br>(Aerospace & Defense)<br>| 136500 | &nbsp;&nbsp; $2207 |
|  | Itau Unibanco Holding SA—ADR <br>(Banks)<br>| 738954 | &nbsp;&nbsp; 5291 |
| \* <br>| MercadoLibre, Inc. <br>(Broadline Retail)<br>| 2340 | &nbsp;&nbsp; 4713 |
| \* <br>| NU Holdings Ltd. <br>(Banks)<br>| 270634 | &nbsp;&nbsp; 4530 |
|  | XP Inc. <br>(Capital Markets)<br>| 82506 | &nbsp;&nbsp; 1351 |
|  |  |  | &nbsp;&nbsp; 26813 |
|  | **Chile—0.5%** | **Chile—0.5%** | **Chile—0.5%** |
|  | Antofagasta PLC <br>(Metals & Mining)<br>| 96956 | &nbsp;&nbsp; 4285 |
|  | **Mexico—0.5%** | **Mexico—0.5%** | **Mexico—0.5%** |
|  | Arca Continental S.A.B. de C.V. <br>(Beverages)<br>| 105800 | &nbsp;&nbsp; 1143 |
|  | Grupo Aeroportuario del Centro Norte <br> S.A.B. de C.V. <br>(Transportation Infrastructure)<br>| 96400 | &nbsp;&nbsp; 1308 |
|  | Grupo Aeroportuario del Sureste S.A.B. <br> de C.V.—ADR <br>(Transportation Infrastructure)<br>| 4956 | &nbsp;&nbsp; 1603 |
|  |  |  | &nbsp;&nbsp; 4054 |
|  | **Peru—0.3%** | **Peru—0.3%** | **Peru—0.3%** |
|  | Credicorp Ltd.<sup>†</sup> <br>(Banks)<br>| 8822 | &nbsp;&nbsp; 2532 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 37684 |
|  | ***Western Hemisphere—4.1%*** |  |  |
|  | **Bermuda—0.6%** | **Bermuda—0.6%** | **Bermuda—0.6%** |
| \* <br>| Arch Capital Group Ltd. <br>(Insurance)<br>| 54849 | &nbsp;&nbsp; 5261 |
|  | **Canada—3.5%** | **Canada—3.5%** | **Canada—3.5%** |
|  | Boyd Group Services, Inc. <br>(Commercial Services & Supplies)<br>| 6204 | &nbsp;&nbsp; 988 |
|  | Intact Financial Corp. <br>(Insurance)<br>| 40458 | &nbsp;&nbsp; 8422 |
| \* <br>| K92 Mining Inc. <br>(Metals & Mining)<br>| 128816 | &nbsp;&nbsp; 2129 |
|  | Lundin Gold Inc. <br>(Metals & Mining)<br>| 75348 | &nbsp;&nbsp; 6259 |
| \* <br>| MDA Space Ltd. <br>(Aerospace & Defense)<br>| 46711 | &nbsp;&nbsp; 907 |
|  | Toromont Industries Ltd. <br>(Trading Companies & Distributors)<br>| 41145 | &nbsp;&nbsp; 4978 |
|  | WSP Global Inc. <br>(Construction & Engineering)<br>| 30418 | &nbsp;&nbsp; 5508 |
|  |  |  | &nbsp;&nbsp; 29191 |
|  | **Total Western Hemisphere** |  | &nbsp;&nbsp; 34452 |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—3.4%*** |  |  |
|  | **South Africa—2.4%** | **South Africa—2.4%** | **South Africa—2.4%** |
|  | Bid Corp. Ltd. <br>(Consumer Staples Distribution & <br> Retail)<br>| 116010 | &nbsp;&nbsp; 2955 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—(continued)***<br>|  |  |
|  | **South Africa—(continued)** | **South Africa—(continued)** | **South Africa—(continued)** |
|  | Capitec Bank Holdings Ltd. <br>(Banks)<br>| 10056 | &nbsp;&nbsp; $2524 |
|  | Clicks Group Ltd. <br>(Consumer Staples Distribution & <br> Retail)<br>| 59592 | &nbsp;&nbsp; 1211 |
|  | FirstRand Limited <br>(Financial Services)<br>| 731942 | &nbsp;&nbsp; 4011 |
|  | Gold Fields Limited <br>(Metals & Mining)<br>| 137190 | &nbsp;&nbsp; 6012 |
|  | MTN Group Limited <br>(Wireless Telecommunication Services)<br>| 299006 | &nbsp;&nbsp; 3061 |
|  |  |  | &nbsp;&nbsp; 19774 |
|  | **United Arab Emirates—1.0%** | **United Arab Emirates—1.0%** | **United Arab Emirates—1.0%** |
|  | Aldar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 501176 | &nbsp;&nbsp; 1187 |
|  | Emaar Development PJSC <br>(Real Estate Management & <br> Development)<br>| 394796 | &nbsp;&nbsp; 1628 |
|  | Emaar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 789592 | &nbsp;&nbsp; 3021 |
|  | Emirates NBD Bank PJSC <br>(Banks)<br>| 384472 | &nbsp;&nbsp; 2915 |
|  |  |  | &nbsp;&nbsp; 8751 |
|  | **Total Emerging Europe, Mid-East,** <br> **Africa**<br>|  | &nbsp;&nbsp; 28525 |
|  | ***Asia Ex-Japan—2.8%*** |  |  |
|  | **Australia—1.0%** | **Australia—1.0%** | **Australia—1.0%** |
| \* <br>| Capricorn Metals Ltd <br>(Metals & Mining)<br>| 217855 | &nbsp;&nbsp; 2091 |
|  | Pro Medicus Ltd. <br>(Health Care Technology)<br>| 11869 | &nbsp;&nbsp; 1750 |
|  | QBE Insurance Group Limited <br>(Insurance)<br>| 175110 | &nbsp;&nbsp; 2324 |
|  | Steadfast Group Ltd. <br>(Insurance)<br>| 482532 | &nbsp;&nbsp; 1700 |
|  |  |  | &nbsp;&nbsp; 7865 |
|  | **Hong Kong—1.5%** | **Hong Kong—1.5%** | **Hong Kong—1.5%** |
|  | AIA Group Ltd. <br>(Insurance)<br>| 599600 | &nbsp;&nbsp; 6156 |
|  | Hong Kong Exchanges & Clearing Ltd. <br>(Capital Markets)<br>| 117700 | &nbsp;&nbsp; 6164 |
|  |  |  | &nbsp;&nbsp; 12320 |
|  | **Singapore—0.3%** | **Singapore—0.3%** | **Singapore—0.3%** |
|  | DBS Group Holdings Ltd. <br>(Banks)<br>| 63160 | &nbsp;&nbsp; 2769 |
|  | **Total Asia Ex-Japan** |  | &nbsp;&nbsp; 22954 |
|  | **Total Common Stocks—98.7%** <br>(cost $619,475)<br>|  | &nbsp;&nbsp; 824162 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**32**

*Annual*

------

**Institutional International Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, <br> 1.150% dated 12/31/25, due 01/02/26, <br> repurchase price $9,958, collateralized <br> by U.S. Treasury Inflation – Indexed <br> Bond, 2.125%, due 02/15/2054, valued <br> at $10,157<br>| $9958 | &nbsp;&nbsp; $9958 |
| **Total Repurchase Agreements—1.2%** <br>(cost $9,958)<br>|  | &nbsp;&nbsp; 9958 |
| **Total Investments—99.9%** <br>(cost $629,433)<br>|  | &nbsp;&nbsp; 834120 |
| **Cash and other assets,** <br>**less liabilities—0.1%**<br>|  | &nbsp;&nbsp; 420 |
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $834540 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $820516 | &nbsp;&nbsp; $3646 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $824162 |
| Repurchase Agreements |  | &nbsp;&nbsp; 9958 | &nbsp;&nbsp; — | &nbsp;&nbsp; 9958 |
| **Total Investments in Securities** | $820516 | &nbsp;&nbsp; $13604 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $834120 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**33**

*William Blair Funds*

------

**International Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Europe Ex-U.K.—32.5%*** |  |  |
|  | **Belgium—1.1%** | **Belgium—1.1%** | **Belgium—1.1%** |
|  | D'ieteren Group <br>(Distributors)<br>| 8126 | &nbsp;&nbsp; $1470 |
|  | **Denmark—0.8%** | **Denmark—0.8%** | **Denmark—0.8%** |
|  | FLSmidth & Co. A/S <br>(Machinery)<br>| 15030 | &nbsp;&nbsp; 1052 |
|  | **France—2.4%** | **France—2.4%** | **France—2.4%** |
|  | Dassault Aviation SA <br>(Aerospace & Defense)<br>| 5517 | &nbsp;&nbsp; 1775 |
|  | VusionGroup <br>(Electronic Equipment, Instruments & <br> Components)<br>| 5496 | &nbsp;&nbsp; 1319 |
|  |  |  | &nbsp;&nbsp; 3094 |
|  | **Germany—4.5%** | **Germany—4.5%** | **Germany—4.5%** |
|  | Atoss Software SE <br>(Software)<br>| 3688 | &nbsp;&nbsp; 500 |
|  | CTS Eventim AG & Co. KGaA <br>(Entertainment)<br>| 20796 | &nbsp;&nbsp; 1919 |
|  | Eckert & Ziegler SE <br>(Health Care Equipment & Supplies)<br>| 28668 | &nbsp;&nbsp; 514 |
|  | flatexDEGIRO AG <br>(Capital Markets)<br>| 41556 | &nbsp;&nbsp; 1794 |
|  | HENSOLDT AG <br>(Aerospace & Defense)<br>| 12405 | &nbsp;&nbsp; 1070 |
|  |  |  | &nbsp;&nbsp; 5797 |
|  | **Israel—1.4%** | **Israel—1.4%** | **Israel—1.4%** |
| \* <br>| Cellebrite DI Ltd. <br>(Software)<br>| 42754 | &nbsp;&nbsp; 771 |
|  | Next Vision Stabilized Systems Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 15794 | &nbsp;&nbsp; 1041 |
|  |  |  | &nbsp;&nbsp; 1812 |
|  | **Italy—6.9%** | **Italy—6.9%** | **Italy—6.9%** |
|  | Azimut Holding SpA <br>(Capital Markets)<br>| 57757 | &nbsp;&nbsp; 2426 |
|  | Brunello Cucinelli SpA <br>(Textiles, Apparel & Luxury Goods)<br>| 15001 | &nbsp;&nbsp; 1735 |
|  | Carel Industries SpA <br>(Building Products)<br>| 37004 | &nbsp;&nbsp; 1068 |
|  | Italgas S.p.A. <br>(Gas Utilities)<br>| 76537 | &nbsp;&nbsp; 856 |
|  | Lottomatica Group S.p.A. <br>(Hotels, Restaurants & Leisure)<br>| 27017 | &nbsp;&nbsp; 711 |
|  | Saipem S.p.A. <br>(Energy Equipment & Services)<br>| 197912 | &nbsp;&nbsp; 564 |
|  | SOL SpA <br>(Chemicals)<br>| 28600 | &nbsp;&nbsp; 1645 |
|  |  |  | &nbsp;&nbsp; 9005 |
|  | **Jersey—0.5%** | **Jersey—0.5%** | **Jersey—0.5%** |
| \* <br>| Rosebank Industries PLC <br>(Industrial Conglomerates)<br>| 148644 | &nbsp;&nbsp; 701 |
|  | **Norway—1.6%** | **Norway—1.6%** | **Norway—1.6%** |
|  | Europris ASA <br>(Broadline Retail)<br>| 71036 | &nbsp;&nbsp; 675 |
|  | Gjensidige Forsikring ASA <br>(Insurance)<br>| 47808 | &nbsp;&nbsp; 1433 |
|  |  |  | &nbsp;&nbsp; 2108 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Europe Ex-U.K.—(continued)*** |  |  |
|  | **Spain—0.9%** | **Spain—0.9%** | **Spain—0.9%** |
|  | Almirall SA <br>(Pharmaceuticals)<br>| 41953 | &nbsp;&nbsp; $633 |
|  | Atalaya Mining Copper SA <br>(Metals & Mining)<br>| 51053 | &nbsp;&nbsp; 588 |
|  |  |  | &nbsp;&nbsp; 1221 |
|  | **Sweden—7.5%** | **Sweden—7.5%** | **Sweden—7.5%** |
|  | AQ Group AB <br>(Electrical Equipment)<br>| 47078 | &nbsp;&nbsp; 1009 |
|  | Beijer Ref AB <br>(Trading Companies & Distributors)<br>| 93553 | &nbsp;&nbsp; 1515 |
|  | Bufab AB <br>(Trading Companies & Distributors)<br>| 158561 | &nbsp;&nbsp; 1732 |
| \* <br>| Dynavox Group AB <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 50176 | &nbsp;&nbsp; 556 |
| \* <br>| Karnov Group AB <br>(Interactive Media & Services)<br>| 56292 | &nbsp;&nbsp; 615 |
|  | Lagercrantz Group AB <br>(Electronic Equipment, Instruments & <br> Components)<br>| 42154 | &nbsp;&nbsp; 974 |
|  | Lifco AB <br>(Industrial Conglomerates)<br>| 19138 | &nbsp;&nbsp; 732 |
| \* <br>| MedCap AB (publ) <br>(Life Sciences Tools & Services)<br>| 9138 | &nbsp;&nbsp; 545 |
|  | Mildef Group AB <br>(Aerospace & Defense)<br>| 52589 | &nbsp;&nbsp; 684 |
|  | RaySearch Laboratories AB <br>(Health Care Technology)<br>| 32677 | &nbsp;&nbsp; 809 |
|  | Sectra AB <br>(Health Care Technology)<br>| 20718 | &nbsp;&nbsp; 565 |
|  |  |  | &nbsp;&nbsp; 9736 |
|  | **Switzerland—4.9%** | **Switzerland—4.9%** | **Switzerland—4.9%** |
|  | Galenica AG <br>(Health Care Providers & Services)<br>| 12146 | &nbsp;&nbsp; 1498 |
|  | Garrett Motion, Inc. <br>(Auto Components)<br>| 41642 | &nbsp;&nbsp; 726 |
|  | Kardex Holding AG <br>(Machinery)<br>| 4431 | &nbsp;&nbsp; 1547 |
|  | Medacta Group SA <br>(Health Care Equipment & Supplies)<br>| 4616 | &nbsp;&nbsp; 911 |
| \* <br>| Sportradar Group AG <br>(Hotels, Restaurants & Leisure)<br>| 50902 | &nbsp;&nbsp; 1210 |
|  | Tecan Group AG <br>(Life Sciences Tools & Services)<br>| 2806 | &nbsp;&nbsp; 455 |
|  |  |  | &nbsp;&nbsp; 6347 |
|  | **Total Europe Ex-U.K.** |  | &nbsp;&nbsp; 42343 |
|  | ***Emerging Asia—19.2%*** |  |  |
|  | **China—1.5%** | **China—1.5%** | **China—1.5%** |
| \* <br>| WuXi XDC Cayman Inc. <br>(Life Sciences Tools & Services)<br>| 108000 | &nbsp;&nbsp; 843 |
|  | Yutong Bus Co. Ltd. <br>(Machinery)<br>| 233600 | &nbsp;&nbsp; 1095 |
|  |  |  | &nbsp;&nbsp; 1938 |
|  | **India—5.2%** | **India—5.2%** | **India—5.2%** |
|  | AU Small Finance Bank Ltd. <br>(Banks)<br>| 143544 | &nbsp;&nbsp; 1591 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**34**

*Annual*

------

**International Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **India—(continued)** | **India—(continued)** | **India—(continued)** |
|  | Central Depository Services India Ltd. <br>(Capital Markets)<br>| 28957 | &nbsp;&nbsp; $466 |
|  | Cholamandalam Financial Holdings <br> Limited <br>(Consumer Finance)<br>| 29140 | &nbsp;&nbsp; 589 |
|  | Gillette India Ltd. <br>(Personal Care Products)<br>| 5732 | &nbsp;&nbsp; 532 |
| \* <br>| GMR Airports Infrastructure Ltd. <br>(Transportation Infrastructure)<br>| 433156 | &nbsp;&nbsp; 502 |
|  | Home First Finance Co. India Ltd. <br>(Financial Services)<br>| 43549 | &nbsp;&nbsp; 533 |
| \* <br>| ITC Hotels Limited <br>(Hotels, Restaurants & Leisure)<br>| 243710 | &nbsp;&nbsp; 535 |
|  | KFin Technologies Ltd. <br>(Capital Markets)<br>| 76620 | &nbsp;&nbsp; 923 |
|  | Sundaram Finance Ltd. <br>(Consumer Finance)<br>| 18132 | &nbsp;&nbsp; 1069 |
|  |  |  | &nbsp;&nbsp; 6740 |
|  | **Indonesia—0.3%** | **Indonesia—0.3%** | **Indonesia—0.3%** |
|  | Bank Syariah Indonesia Tbk. PT <br>(Banks)<br>| 2746800 | &nbsp;&nbsp; 367 |
|  | **South Korea—2.4%** | **South Korea—2.4%** | **South Korea—2.4%** |
|  | DB Insurance Co., Ltd. <br>(Insurance)<br>| 7315 | &nbsp;&nbsp; 666 |
|  | Hansol Chemical Co., Ltd. <br>(Chemicals)<br>| 6240 | &nbsp;&nbsp; 986 |
|  | HD Hyundai Marine Solution Co., Ltd. <br>(Machinery)<br>| 4097 | &nbsp;&nbsp; 550 |
|  | JB Financial Group Co. Ltd. <br>(Banks)<br>| 56622 | &nbsp;&nbsp; 1008 |
|  |  |  | &nbsp;&nbsp; 3210 |
|  | **Taiwan—9.4%** | **Taiwan—9.4%** | **Taiwan—9.4%** |
|  | ASPEED Technology, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 6000 | &nbsp;&nbsp; 1386 |
|  | Bizlink Holding Inc. <br>(Electrical Equipment)<br>| 41000 | &nbsp;&nbsp; 1984 |
|  | Chroma ATE, Inc. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 56000 | &nbsp;&nbsp; 1381 |
|  | Elite Material Co. Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 17000 | &nbsp;&nbsp; 890 |
|  | Hon. Precision, Inc <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 16428 | &nbsp;&nbsp; 1791 |
|  | Innodisk Corp. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 57000 | &nbsp;&nbsp; 1045 |
|  | Jentech Precision Industrial Co. Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 17000 | &nbsp;&nbsp; 1485 |
|  | MiTAC Holdings Corporation <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 212000 | &nbsp;&nbsp; 583 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **Taiwan—(continued)** | **Taiwan—(continued)** | **Taiwan—(continued)** |
|  | Taiwan Union Technology Corporation <br>(Electronic Equipment, Instruments & <br> Components)<br>| 61000 | &nbsp;&nbsp; $959 |
|  | WinWay Technology Co. Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 9000 | &nbsp;&nbsp; 814 |
|  |  |  | &nbsp;&nbsp; 12318 |
|  | **Thailand—0.4%** | **Thailand—0.4%** | **Thailand—0.4%** |
|  | Com7 PCL <br>(Specialty Retail)<br>| 805800 | &nbsp;&nbsp; 501 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 25074 |
|  | ***Japan—17.4%*** |  |  |
|  | Anycolor Inc. <br>(Entertainment)<br>| 16700 | &nbsp;&nbsp; 517 |
|  | Asahi Intecc Co., Ltd. <br>(Health Care Equipment & Supplies)<br>| 48300 | &nbsp;&nbsp; 906 |
|  | AZ-COM MARUWA Holdings, Inc. <br>(Air Freight & Logistics)<br>| 38900 | &nbsp;&nbsp; 245 |
|  | BayCurrent Consulting, Inc. <br>(Professional Services)<br>| 21700 | &nbsp;&nbsp; 900 |
|  | Canon Marketing Japan Inc. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 34100 | &nbsp;&nbsp; 1498 |
|  | Fukuoka Financial Group, Inc. <br>(Banks)<br>| 34800 | &nbsp;&nbsp; 1126 |
|  | Integral Corporation <br>(Capital Markets)<br>| 34500 | &nbsp;&nbsp; 731 |
|  | Internet Initiative Japan, Inc. <br>(Diversified Telecommunication <br> Services)<br>| 76500 | &nbsp;&nbsp; 1351 |
|  | Japan Elevator Service Holdings Co. Ltd. <br>(Commercial Services & Supplies)<br>| 110000 | &nbsp;&nbsp; 1221 |
|  | JMDC Inc. <br>(Health Care Technology)<br>| 20900 | &nbsp;&nbsp; 532 |
|  | Katitas Co., Ltd <br>(Real Estate Management & <br> Development)<br>| 31500 | &nbsp;&nbsp; 641 |
|  | Kokusai Electric Corp. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 27200 | &nbsp;&nbsp; 954 |
|  | Kurita Water Industries Ltd. <br>(Machinery)<br>| 18300 | &nbsp;&nbsp; 742 |
|  | Lifedrink Co., Inc. <br>(Beverages)<br>| 68000 | &nbsp;&nbsp; 755 |
|  | MonotaRO Co. Ltd. <br>(Trading Companies & Distributors)<br>| 67100 | &nbsp;&nbsp; 1071 |
|  | OBIC Business Consultants Co. Ltd. <br>(Software)<br>| 34300 | &nbsp;&nbsp; 1851 |
|  | Oracle Corporation Japan <br>(Software)<br>| 16300 | &nbsp;&nbsp; 1373 |
|  | Organo Corporation <br>(Machinery)<br>| 15200 | &nbsp;&nbsp; 1257 |
| \* <br>| Rakuten Bank Ltd. <br>(Banks)<br>| 28700 | &nbsp;&nbsp; 1266 |
|  | Sanwa Holdings Corporation <br>(Building Products)<br>| 33500 | &nbsp;&nbsp; 872 |
|  | SIGMAXYZ Holdings, Inc. <br>(Professional Services)<br>| 109700 | &nbsp;&nbsp; 580 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**35**

*William Blair Funds*

------

**International Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Japan—(continued)*** |  |  |
|  | Simplex Holdings,Inc. <br>(IT Services)<br>| 93200 | &nbsp;&nbsp; $625 |
|  | SKY Perfect JSAT Holdings Inc. <br>(Media)<br>| 77900 | &nbsp;&nbsp; 992 |
|  | SWCC Corporation <br>(Electrical Equipment)<br>| 9400 | &nbsp;&nbsp; 621 |
|  | **Total Japan** |  | &nbsp;&nbsp; 22627 |
|  | ***United Kingdom—9.3%*** |  |  |
|  | Allfunds Group PLC <br>(Capital Markets)<br>| 106202 | &nbsp;&nbsp; 1004 |
|  | Beazley PLC <br>(Insurance)<br>| 141441 | &nbsp;&nbsp; 1586 |
|  | Diploma PLC <br>(Trading Companies & Distributors)<br>| 15923 | &nbsp;&nbsp; 1137 |
|  | Hill & Smith PLC <br>(Metals & Mining)<br>| 42068 | &nbsp;&nbsp; 1214 |
|  | QinetiQ Group PLC <br>(Aerospace & Defense)<br>| 106576 | &nbsp;&nbsp; 634 |
|  | Renishaw PLC <br>(Electronic Equipment, Instruments & <br> Components)<br>| 13383 | &nbsp;&nbsp; 633 |
|  | Rotork PLC <br>(Machinery)<br>| 339324 | &nbsp;&nbsp; 1488 |
|  | Softcat PLC <br>(IT Services)<br>| 51062 | &nbsp;&nbsp; 975 |
| \* <br>| Trustpilot Group PLC <br>(Interactive Media & Services)<br>| 226725 | &nbsp;&nbsp; 503 |
|  | Volution Group PLC <br>(Building Products)<br>| 168165 | &nbsp;&nbsp; 1462 |
|  | XPS Pensions Group PLC <br>(Capital Markets)<br>| 97151 | &nbsp;&nbsp; 444 |
| \* <br>| Zegona Communications PLC <br>(Diversified Telecommunication <br> Services)<br>| 55657 | &nbsp;&nbsp; 1047 |
|  | **Total United Kingdom** |  | &nbsp;&nbsp; 12127 |
|  | ***Emerging Latin America—7.2%*** |  |  |
|  | **Brazil—1.4%** | **Brazil—1.4%** | **Brazil—1.4%** |
|  | Cury Construtora e Incorporadora SA <br>(Household Durables)<br>| 97600 | &nbsp;&nbsp; 574 |
|  | Inter & Co, Inc. <br>(Banks)<br>| 141781 | &nbsp;&nbsp; 1202 |
|  |  |  | &nbsp;&nbsp; 1776 |
|  | **Chile—0.1%** | **Chile—0.1%** | **Chile—0.1%** |
|  | Enel Chile S.A. <br>(Electric Utilities)<br>| 1787436 | &nbsp;&nbsp; 147 |
|  | **Mexico—4.3%** | **Mexico—4.3%** | **Mexico—4.3%** |
|  | Arca Continental S.A.B. de C.V. <br>(Beverages)<br>| 117100 | &nbsp;&nbsp; 1265 |
|  | Grupo Aeroportuario del Centro Norte <br> S.A.B. de C.V. <br>(Transportation Infrastructure)<br>| 83800 | &nbsp;&nbsp; 1137 |
|  | Grupo Aeroportuario del Sureste S.A.B. de <br> C.V. <br>(Transportation Infrastructure)<br>| 37555 | &nbsp;&nbsp; 1212 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Latin*** <br> ***America—(continued)***<br>|  |  |
|  | **Mexico—(continued)** | **Mexico—(continued)** | **Mexico—(continued)** |
|  | Prologis Property Mexico SA de CV REIT <br>(Industrial REITs)<br>| 318115 | &nbsp;&nbsp; $1329 |
|  | Qualitas Controladora S.A.B. de C.V. <br>(Insurance)<br>| 69800 | &nbsp;&nbsp; 721 |
|  |  |  | &nbsp;&nbsp; 5664 |
|  | **Panama—0.6%** | **Panama—0.6%** | **Panama—0.6%** |
|  | Banco Latinoamericano de Comercio <br> Exterior, S.A. <br>(Financial Services)<br>| 17119 | &nbsp;&nbsp; 763 |
|  | **Peru—0.8%** | **Peru—0.8%** | **Peru—0.8%** |
|  | Intercorp Financial Services Inc <br>(Banks)<br>| 23487 | &nbsp;&nbsp; 995 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 9345 |
|  | ***Western Hemisphere—5.7%*** |  |  |
|  | **Canada—5.1%** | **Canada—5.1%** | **Canada—5.1%** |
|  | Boyd Group Services, Inc. <br>(Commercial Services & Supplies)<br>| 7043 | &nbsp;&nbsp; 1122 |
|  | Definity Financial Corp. <br>(Insurance)<br>| 30877 | &nbsp;&nbsp; 1708 |
|  | Exchange Income Corporation <br>(Airlines)<br>| 11217 | &nbsp;&nbsp; 670 |
| \* <br>| K92 Mining Inc. <br>(Metals & Mining)<br>| 65659 | &nbsp;&nbsp; 1085 |
| \* <br>| MDA Space Ltd. <br>(Aerospace & Defense)<br>| 25914 | &nbsp;&nbsp; 503 |
|  | North West Co., Inc. <br>(Consumer Staples Distribution & <br> Retail)<br>| 44502 | &nbsp;&nbsp; 1586 |
|  |  |  | &nbsp;&nbsp; 6674 |
|  | **United States—0.6%** | **United States—0.6%** | **United States—0.6%** |
|  | Aura Minerals Inc. <br>(Metals & Mining)<br>| 14187 | &nbsp;&nbsp; 715 |
|  | **Total Western Hemisphere** |  | &nbsp;&nbsp; 7389 |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—4.1%*** |  |  |
|  | **Greece—1.1%** | **Greece—1.1%** | **Greece—1.1%** |
|  | JUMBO SA <br>(Specialty Retail)<br>| 42851 | &nbsp;&nbsp; 1405 |
|  | **Poland—1.4%** | **Poland—1.4%** | **Poland—1.4%** |
| \* <br>| Benefit Systems SA <br>(Professional Services)<br>| 755 | &nbsp;&nbsp; 738 |
| \* <br>| Zabka Group <br>(Consumer Staples Distribution & <br> Retail)<br>| 176797 | &nbsp;&nbsp; 1128 |
|  |  |  | &nbsp;&nbsp; 1866 |
|  | **South Africa—0.7%** | **South Africa—0.7%** | **South Africa—0.7%** |
|  | OUTsurance Group Ltd. <br>(Insurance)<br>| 218935 | &nbsp;&nbsp; 947 |
|  | **Turkey—0.9%** | **Turkey—0.9%** | **Turkey—0.9%** |
|  | ASELSAN Elektronik Sanayi ve Ticaret <br> A.S. <br>(Aerospace & Defense)<br>| 205938 | &nbsp;&nbsp; 1112 |
|  | **Total Emerging Europe, Mid-East,** <br> **Africa**<br>|  | &nbsp;&nbsp; 5330 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**36**

*Annual*

------

**International Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Asia Ex-Japan—3.3%*** |  |  |
|  | **Australia—3.3%** | **Australia—3.3%** | **Australia—3.3%** |
| \* <br>| Capricorn Metals Ltd <br>(Metals & Mining)<br>| 104972 | &nbsp;&nbsp; $1008 |
| \* <br>| Catapult Group International Ltd. <br>(Software)<br>| 307402 | &nbsp;&nbsp; 851 |
|  | Pro Medicus Ltd. <br>(Health Care Technology)<br>| 5940 | &nbsp;&nbsp; 876 |
| \* <br>| Qoria Limited <br>(Software)<br>| 1398833 | &nbsp;&nbsp; 546 |
|  | Steadfast Group Ltd. <br>(Insurance)<br>| 314544 | &nbsp;&nbsp; 1108 |
|  | **Total Asia Ex-Japan** |  | &nbsp;&nbsp; 4389 |
|  | **Total Common Stocks—98.7%** <br>(cost $102,508)<br>|  | &nbsp;&nbsp; 128624 |

---

---

| | | |
|:---|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $1,424, collateralized by <br> U.S. Treasury Inflation – Indexed Bond, <br> 1.375%, due 02/15/2044, valued at <br> $1,452<br>| $1424 | &nbsp;&nbsp; 1424 |
| **Total Repurchase Agreements—1.1%** <br>(cost $1,424)<br>|  | &nbsp;&nbsp; 1424 |
| **Total Investments—99.8%** <br>(cost $103,932)<br>|  | &nbsp;&nbsp; 130048 |
| **Cash and other assets,** <br>**less liabilities—0.2%**<br>|  | &nbsp;&nbsp; 204 |
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $130252 |

---

------

PLC Public Limited Company <br> REIT Real Estate Investment Trust

\* Non-income producing security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $128123 | &nbsp;&nbsp; $501 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $128624 |
| Repurchase Agreements |  | &nbsp;&nbsp; 1424 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1424 |
| **Total Investments in Securities** | $128123 | &nbsp;&nbsp; $1925 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $130048 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**37**

*William Blair Funds*

------

**Emerging Markets Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Emerging Asia—74.1%*** |  |  |
|  | **China—20.8%** | **China—20.8%** | **China—20.8%** |
|  | Alibaba Group Holding Ltd. <br>(Broadline Retail)<br>| 175328 | &nbsp;&nbsp; $3217 |
|  | Contemporary Amperex Technology Co. <br> Ltd. <br>(Electrical Equipment)<br>| 43720 | &nbsp;&nbsp; 2302 |
|  | Fuyao Glass Industry Group Co. Ltd. <br>(Auto Components)<br>| 212500 | &nbsp;&nbsp; 1973 |
|  | Huaming Power Equipment Co. Ltd. <br>(Machinery)<br>| 204560 | &nbsp;&nbsp; 734 |
| \* <br>| JD Health International Inc. <br>(Consumer Staples Distribution & Retail)<br>| 126850 | &nbsp;&nbsp; 905 |
|  | NetEase, Inc. <br>(Entertainment)<br>| 88900 | &nbsp;&nbsp; 2451 |
|  | Tencent Holdings Ltd. <br>(Interactive Media & Services)<br>| 85200 | &nbsp;&nbsp; 6558 |
| \* <br>| WuXi XDC Cayman Inc. <br>(Life Sciences Tools & Services)<br>| 231000 | &nbsp;&nbsp; 1803 |
|  |  |  | &nbsp;&nbsp; 19943 |
|  | **India—18.8%** | **India—18.8%** | **India—18.8%** |
|  | Bajaj Finance Limited <br>(Consumer Finance)<br>| 127210 | &nbsp;&nbsp; 1396 |
|  | Bharat Electronics Ltd. <br>(Aerospace & Defense)<br>| 418963 | &nbsp;&nbsp; 1861 |
|  | Bharti Airtel Ltd. <br>(Wireless Telecommunication Services)<br>| 109358 | &nbsp;&nbsp; 2564 |
|  | CG Power & Industrial Solutions Ltd. <br>(Electrical Equipment)<br>| 125735 | &nbsp;&nbsp; 906 |
|  | Coforge Limited <br>(IT Services)<br>| 54408 | &nbsp;&nbsp; 1008 |
|  | Eicher Motors Limited <br>(Automobiles)<br>| 14448 | &nbsp;&nbsp; 1176 |
| \* <br>| GMR Airports Infrastructure Ltd. <br>(Transportation Infrastructure)<br>| 1357700 | &nbsp;&nbsp; 1574 |
|  | HDFC Bank Ltd. <br>(Banks)<br>| 244674 | &nbsp;&nbsp; 2703 |
|  | Macrotech Developers Ltd. <br>(Real Estate Management & <br> Development)<br>| 123945 | &nbsp;&nbsp; 1463 |
|  | Marico Limited <br>(Food Products)<br>| 157479 | &nbsp;&nbsp; 1315 |
|  | Max Healthcare Institute Ltd. <br>(Health Care Providers & Services)<br>| 86640 | &nbsp;&nbsp; 1007 |
| \* <br>| Zomato Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 343730 | &nbsp;&nbsp; 1063 |
|  |  |  | &nbsp;&nbsp; 18036 |
|  | **Indonesia—4.1%** | **Indonesia—4.1%** | **Indonesia—4.1%** |
|  | Bank Central Asia Tbk. PT <br>(Banks)<br>| 3666300 | &nbsp;&nbsp; 1776 |
| \* <br>| Grab Holdings Limited <br>(Road & Rail)<br>| 287412 | &nbsp;&nbsp; 1434 |
| \* <br>| Sea Ltd.—ADR <br>(Entertainment)<br>| 5945 | &nbsp;&nbsp; 758 |
|  |  |  | &nbsp;&nbsp; 3968 |
|  | **South Korea—13.4%** | **South Korea—13.4%** | **South Korea—13.4%** |
|  | HD Hyundai Marine Solution Co., Ltd. <br>(Machinery)<br>| 7480 | &nbsp;&nbsp; 1005 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **South Korea—(continued)** | **South Korea—(continued)** | **South Korea—(continued)** |
|  | HD Korea Shipbuilding & Offshore <br> Engineering Co., Ltd. <br>(Machinery)<br>| 3999 | &nbsp;&nbsp; $1130 |
|  | Kakao Corp. <br>(Interactive Media & Services)<br>| 35057 | &nbsp;&nbsp; 1462 |
| \* <br>| Samsung Biologics Co. Ltd. <br>(Life Sciences Tools & Services)<br>| 1347 | &nbsp;&nbsp; 1585 |
|  | Samsung Electronics Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 42151 | &nbsp;&nbsp; 3508 |
|  | SK Hynix, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 9050 | &nbsp;&nbsp; 4090 |
|  |  |  | &nbsp;&nbsp; 12780 |
|  | **Taiwan—17.0%** | **Taiwan—17.0%** | **Taiwan—17.0%** |
|  | ASPEED Technology, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 5000 | &nbsp;&nbsp; 1155 |
|  | Hon Hai Precision Industry Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 252000 | &nbsp;&nbsp; 1849 |
|  | Taiwan Semiconductor Manufacturing Co. <br> Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 146000 | &nbsp;&nbsp; 7202 |
|  | Taiwan Semiconductor Manufacturing Co. <br> Ltd.—ADR <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 19998 | &nbsp;&nbsp; 6077 |
|  |  |  | &nbsp;&nbsp; 16283 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 71010 |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—12.3%*** |  |  |
|  | **Greece—0.9%** | **Greece—0.9%** | **Greece—0.9%** |
|  | Eurobank S.A. <br>(Banks)<br>| 219946 | &nbsp;&nbsp; 885 |
|  | **Poland—2.1%** | **Poland—2.1%** | **Poland—2.1%** |
|  | PKO Bank Polski S.A. <br>(Banks)<br>| 50078 | &nbsp;&nbsp; 1188 |
| \* <br>| Zabka Group <br>(Consumer Staples Distribution & Retail)<br>| 119392 | &nbsp;&nbsp; 762 |
|  |  |  | &nbsp;&nbsp; 1950 |
|  | **South Africa—6.5%** | **South Africa—6.5%** | **South Africa—6.5%** |
|  | Capitec Bank Holdings Ltd. <br>(Banks)<br>| 4241 | &nbsp;&nbsp; 1064 |
|  | Clicks Group Ltd. <br>(Consumer Staples Distribution & Retail)<br>| 49237 | &nbsp;&nbsp; 1001 |
|  | FirstRand Limited <br>(Financial Services)<br>| 248411 | &nbsp;&nbsp; 1361 |
|  | Gold Fields Limited <br>(Metals & Mining)<br>| 40785 | &nbsp;&nbsp; 1788 |
|  | Naspers Limited <br>(Broadline Retail)<br>| 15054 | &nbsp;&nbsp; 1004 |
|  |  |  | &nbsp;&nbsp; 6218 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**38**

*Annual*

------

**Emerging Markets Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—(continued)***<br>|  |  |
|  | **United Arab Emirates—2.8%** | **United Arab Emirates—2.8%** | **United Arab Emirates—2.8%** |
|  | Aldar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 610748 | &nbsp;&nbsp; $1447 |
|  | Emirates NBD Bank PJSC <br>(Banks)<br>| 167043 | &nbsp;&nbsp; 1266 |
|  |  |  | &nbsp;&nbsp; 2713 |
|  | **Total Emerging Europe, Mid-East, Africa** |  | &nbsp;&nbsp; 11766 |
|  | ***Emerging Latin America—11.1%*** |  |  |
|  | **Brazil—7.8%** | **Brazil—7.8%** | **Brazil—7.8%** |
|  | Embraer S.A. <br>(Aerospace & Defense)<br>| 71200 | &nbsp;&nbsp; 1151 |
|  | Inter & Co, Inc. <br>(Banks)<br>| 182904 | &nbsp;&nbsp; 1551 |
|  | Itau Unibanco Holding SA—ADR <br>(Banks)<br>| 212392 | &nbsp;&nbsp; 1521 |
| \* <br>| MercadoLibre, Inc. <br>(Broadline Retail)<br>| 389 | &nbsp;&nbsp; 784 |
| \* <br>| NU Holdings Ltd. <br>(Banks)<br>| 148755 | &nbsp;&nbsp; 2490 |
|  |  |  | &nbsp;&nbsp; 7497 |
|  | **Mexico—1.6%** | **Mexico—1.6%** | **Mexico—1.6%** |
| \* <br>| BBB Foods, Inc. <br>(Consumer Staples Distribution & Retail)<br>| 19766 | &nbsp;&nbsp; 660 |
|  | Grupo Financiero Banorte S.A.B. de C.V. <br>(Banks)<br>| 91900 | &nbsp;&nbsp; 851 |
|  |  |  | &nbsp;&nbsp; 1511 |
|  | **Peru—1.7%** | **Peru—1.7%** | **Peru—1.7%** |
|  | Credicorp Ltd.<sup>†</sup> <br>(Banks)<br>| 5588 | &nbsp;&nbsp; 1604 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 10612 |
|  | ***Asia Ex-Japan—1.4%*** |  |  |
|  | **Hong Kong—1.4%** | **Hong Kong—1.4%** | **Hong Kong—1.4%** |
|  | AIA Group Ltd. <br>(Insurance)<br>| 132800 | &nbsp;&nbsp; 1363 |
|  | **Total Common Stocks—98.9%** <br>(cost $72,499)<br>|  | &nbsp;&nbsp; 94751 |

---

---

| | | |
|:---|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $1,502, collateralized by <br> U.S. Treasury Inflation – Indexed Bond, <br> 2.125%, due 02/15/2054, valued at $1,532<br>| $1502 | &nbsp;&nbsp; 1502 |
| **Total Repurchase Agreements—1.6%** <br>(cost $1,502)<br>|  | &nbsp;&nbsp; 1502 |
| **Total Investments—100.5%** <br>(cost $74,001)<br>|  | &nbsp;&nbsp; 96253 |
| **Liabilities, plus cash and** <br>**other assets—(0.5)%**<br>|  | &nbsp;&nbsp; (490)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $95763 |

---

------

ADR American Depositary Receipt

\* Non-income producing security <br> † U.S. listed foreign security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**39**

*William Blair Funds*

------

**Emerging Markets Leaders Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $94751 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $94751 |
| Repurchase Agreements |  | &nbsp;&nbsp; 1502 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1502 |
| **Total Investments in Securities** | $94751 | &nbsp;&nbsp; $1502 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $96253 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**40**

*Annual*

------

**Emerging Markets Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Emerging Asia—77.5%*** |  |  |
|  | **China—20.7%** | **China—20.7%** | **China—20.7%** |
|  | Alibaba Group Holding Ltd. <br>(Broadline Retail)<br>| 2182500 | &nbsp;&nbsp; $40045 |
| \* <br>| BeOne Medicines Ltd <br>(Biotechnology)<br>| 136200 | &nbsp;&nbsp; 3138 |
|  | CMOC Group Limited <br>(Metals & Mining)<br>| 1500000 | &nbsp;&nbsp; 3708 |
|  | Contemporary Amperex Technology Co. <br> Ltd. <br>(Electrical Equipment)<br>| 262171 | &nbsp;&nbsp; 13803 |
|  | Eoptolink Technology Inc., Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 62500 | &nbsp;&nbsp; 3861 |
|  | Hansoh Pharmaceutical Group <br> Company Limited <br>(Pharmaceuticals)<br>| 672000 | &nbsp;&nbsp; 3115 |
| \* <br>| JD Health International Inc. <br>(Consumer Staples Distribution & <br> Retail)<br>| 614350 | &nbsp;&nbsp; 4381 |
| \* <br>| Jiangsu Hengrui Pharmaceuticals <br> Co.,Ltd <br>(Pharmaceuticals)<br>| 414000 | &nbsp;&nbsp; 3790 |
|  | NetEase, Inc. <br>(Entertainment)<br>| 500400 | &nbsp;&nbsp; 13798 |
|  | Neway Valve (Suzhou) Co., Ltd. <br>(Machinery)<br>| 439300 | &nbsp;&nbsp; 3273 |
|  | Shenzhen Inovance Technology Co. <br> Ltd. <br>(Machinery)<br>| 283500 | &nbsp;&nbsp; 3062 |
|  | Tencent Holdings Ltd. <br>(Interactive Media & Services)<br>| 851260 | &nbsp;&nbsp; 65519 |
|  | Tencent Music Entertainment <br> Group—ADR <br>(Entertainment)<br>| 415539 | &nbsp;&nbsp; 7284 |
|  | Trip.com Group Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 107600 | &nbsp;&nbsp; 7659 |
|  | Victory Giant Technology (HuiZhou) <br> Co., Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 93635 | &nbsp;&nbsp; 3860 |
|  | Weichai Power Co. Ltd. <br>(Machinery)<br>| 1219000 | &nbsp;&nbsp; 2953 |
|  | WUS Printed Circuit Kunshan Co. Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 340250 | &nbsp;&nbsp; 3564 |
|  | WuXi AppTec Co., Ltd. <br>(Life Sciences Tools & Services)<br>| 332600 | &nbsp;&nbsp; 4218 |
| \* <br>| WuXi XDC Cayman Inc. <br>(Life Sciences Tools & Services)<br>| 488000 | &nbsp;&nbsp; 3809 |
|  | Yutong Bus Co. Ltd. <br>(Machinery)<br>| 781000 | &nbsp;&nbsp; 3661 |
|  | Zhongji Innolight Co. Ltd. <br>(Communications Equipment)<br>| 70500 | &nbsp;&nbsp; 6165 |
|  | Zijin Mining Group Company Limited <br>(Metals & Mining)<br>| 1186000 | &nbsp;&nbsp; 5434 |
|  |  |  | &nbsp;&nbsp; 210100 |
|  | **India—13.4%** | **India—13.4%** | **India—13.4%** |
|  | Apollo Hospitals Enterprise Ltd. <br>(Health Care Providers & Services)<br>| 32365 | &nbsp;&nbsp; 2535 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **India—(continued)** | **India—(continued)** | **India—(continued)** |
|  | Bajaj Finance Limited <br>(Consumer Finance)<br>| 1145311 | &nbsp;&nbsp; $12571 |
|  | Bharat Electronics Ltd. <br>(Aerospace & Defense)<br>| 1522178 | &nbsp;&nbsp; 6761 |
|  | Bharti Airtel Ltd. <br>(Wireless Telecommunication <br> Services)<br>| 660568 | &nbsp;&nbsp; 15485 |
|  | Central Depository Services India Ltd. <br>(Capital Markets)<br>| 140739 | &nbsp;&nbsp; 2264 |
|  | Cummins India Ltd. <br>(Machinery)<br>| 61777 | &nbsp;&nbsp; 3043 |
|  | Eicher Motors Limited <br>(Automobiles)<br>| 60786 | &nbsp;&nbsp; 4947 |
|  | GE Vernova T&D India Ltd. <br>(Electrical Equipment)<br>| 150112 | &nbsp;&nbsp; 5231 |
|  | HDFC Asset Management Co. Ltd. <br>(Capital Markets)<br>| 140704 | &nbsp;&nbsp; 4188 |
|  | HDFC Bank Ltd. <br>(Banks)<br>| 1384825 | &nbsp;&nbsp; 15298 |
|  | Hindustan Aeronautics Ltd. <br>(Aerospace & Defense)<br>| 94658 | &nbsp;&nbsp; 4619 |
|  | Hitachi Energy India Ltd. <br>(Electrical Equipment)<br>| 15606 | &nbsp;&nbsp; 3171 |
|  | ICICI Bank Ltd. <br>(Banks)<br>| 1000819 | &nbsp;&nbsp; 14954 |
|  | Indian Hotels Co. Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 311213 | &nbsp;&nbsp; 2553 |
|  | Mahindra & Mahindra Ltd. <br>(Automobiles)<br>| 184173 | &nbsp;&nbsp; 7614 |
|  | Max Healthcare Institute Ltd. <br>(Health Care Providers & Services)<br>| 208539 | &nbsp;&nbsp; 2425 |
|  | Radico Khaitan Ltd. <br>(Beverages)<br>| 67928 | &nbsp;&nbsp; 2490 |
|  | Reliance Industries Ltd. <br>(Oil, Gas & Consumable Fuels)<br>| 874066 | &nbsp;&nbsp; 15258 |
|  | TVS Motor Co. Ltd. <br>(Automobiles)<br>| 115052 | &nbsp;&nbsp; 4762 |
|  | UNO Minda Ltd. <br>(Auto Components)<br>| 219490 | &nbsp;&nbsp; 3121 |
| \* <br>| Zomato Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 934680 | &nbsp;&nbsp; 2892 |
|  |  |  | &nbsp;&nbsp; 136182 |
|  | **Indonesia—2.7%** | **Indonesia—2.7%** | **Indonesia—2.7%** |
|  | Bank Central Asia Tbk. PT <br>(Banks)<br>| 15772695 | &nbsp;&nbsp; 7638 |
| \* <br>| Grab Holdings Limited <br>(Road & Rail)<br>| 1206315 | &nbsp;&nbsp; 6020 |
| \* <br>| Sea Ltd.—ADR <br>(Entertainment)<br>| 109203 | &nbsp;&nbsp; 13931 |
|  |  |  | &nbsp;&nbsp; 27589 |
|  | **Philippines—1.0%** | **Philippines—1.0%** | **Philippines—1.0%** |
|  | BDO Unibank, Inc. <br>(Banks)<br>| 1928479 | &nbsp;&nbsp; 4412 |
|  | International Container Terminal <br> Services, Inc. <br>(Transportation Infrastructure)<br>| 607280 | &nbsp;&nbsp; 5853 |
|  |  |  | &nbsp;&nbsp; 10265 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**41**

*William Blair Funds*

------

**Emerging Markets Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **South Korea—15.7%** | **South Korea—15.7%** | **South Korea—15.7%** |
|  | Hanwha Aerospace Co. Ltd. <br>(Aerospace & Defense)<br>| 12710 | &nbsp;&nbsp; $8302 |
|  | HD Hyundai Electric Co. Ltd. <br>(Electrical Equipment)<br>| 14578 | &nbsp;&nbsp; 7833 |
|  | HD Hyundai Heavy Industries Co., Ltd. <br>(Machinery)<br>| 27236 | &nbsp;&nbsp; 9623 |
|  | HD Hyundai Marine Solution Co., Ltd. <br>(Machinery)<br>| 27144 | &nbsp;&nbsp; 3646 |
|  | Hyosung Heavy Industries Corporation <br>(Electrical Equipment)<br>| 4806 | &nbsp;&nbsp; 5942 |
|  | Hyundai Rotem Company <br>(Machinery)<br>| 37234 | &nbsp;&nbsp; 4857 |
|  | IsuPetasys Co., Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 43817 | &nbsp;&nbsp; 3626 |
|  | Kakao Corp. <br>(Interactive Media & Services)<br>| 82313 | &nbsp;&nbsp; 3434 |
| \* <br>| Samsung Biologics Co. Ltd. <br>(Life Sciences Tools & Services)<br>| 3752 | &nbsp;&nbsp; 4415 |
|  | Samsung Electronics Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 608456 | &nbsp;&nbsp; 50643 |
|  | Samyangfoods Co., Ltd <br>(Food Products)<br>| 3512 | &nbsp;&nbsp; 3001 |
|  | SK Hynix, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 88942 | &nbsp;&nbsp; 40194 |
| \* <br>| SK Square Co., Ltd. <br>(Industrial Conglomerates)<br>| 53646 | &nbsp;&nbsp; 13704 |
|  |  |  | &nbsp;&nbsp; 159220 |
|  | **Taiwan—23.5%** | **Taiwan—23.5%** | **Taiwan—23.5%** |
|  | Accton Technology Corp. <br>(Communications Equipment)<br>| 158000 | &nbsp;&nbsp; 5959 |
|  | Asia Vital Components Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 146000 | &nbsp;&nbsp; 7016 |
|  | ASPEED Technology, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 41300 | &nbsp;&nbsp; 9543 |
|  | Bizlink Holding Inc. <br>(Electrical Equipment)<br>| 101968 | &nbsp;&nbsp; 4933 |
|  | Chroma ATE, Inc. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 175000 | &nbsp;&nbsp; 4316 |
|  | Delta Electronics, Inc. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 484000 | &nbsp;&nbsp; 14834 |
|  | Elite Material Co. Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 172000 | &nbsp;&nbsp; 9005 |
|  | Gold Circuit Electronics Ltd. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 223000 | &nbsp;&nbsp; 4876 |
|  | Hon. Precision, Inc <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 44371 | &nbsp;&nbsp; 4837 |
|  | Jentech Precision Industrial Co. Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 37000 | &nbsp;&nbsp; 3232 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **Taiwan—(continued)** | **Taiwan—(continued)** | **Taiwan—(continued)** |
|  | King Slide Works Co., Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 45000 | &nbsp;&nbsp; $5371 |
|  | Taiwan Semiconductor Manufacturing <br> Co. Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 523000 | &nbsp;&nbsp; 25800 |
|  | Taiwan Semiconductor Manufacturing <br> Co. Ltd.—ADR <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 407458 | &nbsp;&nbsp; 123822 |
|  | Unimicron Technology Corp. <br>(Electronic Equipment, Instruments <br> & Components)<br>| 618000 | &nbsp;&nbsp; 4327 |
|  | Wiwynn Corp. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 73000 | &nbsp;&nbsp; 10420 |
|  |  |  | &nbsp;&nbsp; 238291 |
|  | **Thailand—0.5%** | **Thailand—0.5%** | **Thailand—0.5%** |
| \* <br>| Fabrinet <br>(Electronic Equipment, Instruments <br> & Components)<br>| 10816 | &nbsp;&nbsp; 4924 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 786571 |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—11.3%*** |  |  |
|  | **Czech Republic—0.4%** | **Czech Republic—0.4%** | **Czech Republic—0.4%** |
|  | Komercni banka, a.s. <br>(Banks)<br>| 62778 | &nbsp;&nbsp; 3548 |
|  | **Greece—2.3%** | **Greece—2.3%** | **Greece—2.3%** |
|  | Eurobank S.A. <br>(Banks)<br>| 3058013 | &nbsp;&nbsp; 12309 |
|  | JUMBO SA <br>(Specialty Retail)<br>| 64349 | &nbsp;&nbsp; 2110 |
|  | OPAP S.A. <br>(Hotels, Restaurants & Leisure)<br>| 118266 | &nbsp;&nbsp; 2655 |
|  | Piraeus Bank S.A. <br>(Banks)<br>| 814176 | &nbsp;&nbsp; 6500 |
|  |  |  | &nbsp;&nbsp; 23574 |
|  | **Hungary—1.2%** | **Hungary—1.2%** | **Hungary—1.2%** |
|  | OTP Bank Nyrt. PLC <br>(Banks)<br>| 112189 | &nbsp;&nbsp; 12041 |
|  | **Kazakhstan—0.2%** | **Kazakhstan—0.2%** | **Kazakhstan—0.2%** |
|  | NAC Kazatomprom JSC <br>(Oil, Gas & Consumable Fuels)<br>| 40441 | &nbsp;&nbsp; 2257 |
|  | **Poland—0.3%** | **Poland—0.3%** | **Poland—0.3%** |
|  | PKO Bank Polski S.A. <br>(Banks)<br>| 143144 | &nbsp;&nbsp; 3396 |
|  | **Saudi Arabia—0.3%** | **Saudi Arabia—0.3%** | **Saudi Arabia—0.3%** |
|  | The Saudi National Bank <br>(Banks)<br>| 340052 | &nbsp;&nbsp; 3434 |
|  | **South Africa—3.8%** | **South Africa—3.8%** | **South Africa—3.8%** |
|  | Capitec Bank Holdings Ltd. <br>(Banks)<br>| 59574 | &nbsp;&nbsp; 14950 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**42**

*Annual*

------

**Emerging Markets Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—(continued)***<br>|  |  |
|  | **South Africa—(continued)** | **South Africa—(continued)** | **South Africa—(continued)** |
|  | Naspers Limited <br>(Broadline Retail)<br>| 317093 | &nbsp;&nbsp; $21149 |
|  | OUTsurance Group Ltd. <br>(Insurance)<br>| 518265 | &nbsp;&nbsp; 2243 |
|  |  |  | &nbsp;&nbsp; 38342 |
|  | **Turkey—0.6%** | **Turkey—0.6%** | **Turkey—0.6%** |
|  | ASELSAN Elektronik Sanayi ve Ticaret <br> A.S. <br>(Aerospace & Defense)<br>| 1070477 | &nbsp;&nbsp; 5779 |
|  | **United Arab Emirates—2.2%** | **United Arab Emirates—2.2%** | **United Arab Emirates—2.2%** |
|  | Abu Dhabi Islamic Bank PJSC <br>(Banks)<br>| 812797 | &nbsp;&nbsp; 4594 |
|  | Aldar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 2126641 | &nbsp;&nbsp; 5038 |
|  | Emaar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 1329315 | &nbsp;&nbsp; 5085 |
|  | Emirates NBD Bank PJSC <br>(Banks)<br>| 632262 | &nbsp;&nbsp; 4794 |
|  | Salik Co. PJSC <br>(Transportation Infrastructure)<br>| 1527761 | &nbsp;&nbsp; 2642 |
|  |  |  | &nbsp;&nbsp; 22153 |
|  | **Total Emerging Europe, Mid-East,** <br> **Africa**<br>|  | &nbsp;&nbsp; 114524 |
|  | ***Emerging Latin America—9.1%*** |  |  |
|  | **Brazil—5.9%** | **Brazil—5.9%** | **Brazil—5.9%** |
| \* <br>| Banco BTG Pactual SA <br>(Capital Markets)<br>| 1277400 | &nbsp;&nbsp; 12257 |
|  | Companhia de Saneamento Basico do <br> Estado de Sao Paulo - SABESP <br>(Water Utilities)<br>| 139311 | &nbsp;&nbsp; 3391 |
|  | Cury Construtora e Incorporadora SA <br>(Household Durables)<br>| 357600 | &nbsp;&nbsp; 2104 |
|  | Direcional Engenharia SA <br>(Household Durables)<br>| 751400 | &nbsp;&nbsp; 1936 |
|  | Embraer S.A. <br>(Aerospace & Defense)<br>| 253900 | &nbsp;&nbsp; 4105 |
|  | Itau Unibanco Holding SA—ADR <br>(Banks)<br>| 1698327 | &nbsp;&nbsp; 12160 |
| \* <br>| MercadoLibre, Inc. <br>(Broadline Retail)<br>| 7153 | &nbsp;&nbsp; 14408 |
| \* <br>| NU Holdings Ltd.<sup>†</sup> <br>(Banks)<br>| 574440 | &nbsp;&nbsp; 9616 |
|  |  |  | &nbsp;&nbsp; 59977 |
|  | **Chile—1.7%** | **Chile—1.7%** | **Chile—1.7%** |
|  | Antofagasta PLC <br>(Metals & Mining)<br>| 123809 | &nbsp;&nbsp; 5473 |
|  | Banco de Chile <br>(Banks)<br>| 18545763 | &nbsp;&nbsp; 3582 |
|  | Falabella S.A. <br>(Broadline Retail)<br>| 578575 | &nbsp;&nbsp; 4036 |
|  | LATAM Airlines Group S.A.—ADR <br>(Airlines)<br>| 72062 | &nbsp;&nbsp; 3892 |
|  |  |  | &nbsp;&nbsp; 16983 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Latin*** <br> ***America—(continued)***<br>|  |  |
|  | **Mexico—0.7%** | **Mexico—0.7%** | **Mexico—0.7%** |
|  | Grupo Financiero Banorte S.A.B. de <br> C.V. <br>(Banks)<br>| 460800 | &nbsp;&nbsp; $4269 |
|  | Prologis Property Mexico SA de CV <br> REIT <br>(Industrial REITs)<br>| 659729 | &nbsp;&nbsp; 2756 |
|  |  |  | &nbsp;&nbsp; 7025 |
|  | **Peru—0.8%** | **Peru—0.8%** | **Peru—0.8%** |
|  | Credicorp Ltd. <br>(Banks)<br>| 27088 | &nbsp;&nbsp; 7774 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 91759 |
|  | ***Asia Ex-Japan—1.2%*** |  |  |
|  | **Hong Kong—1.2%** | **Hong Kong—1.2%** | **Hong Kong—1.2%** |
|  | Hong Kong Exchanges & Clearing Ltd. <br>(Capital Markets)<br>| 235300 | &nbsp;&nbsp; 12323 |
|  | ***Western Hemisphere—0.3%*** |  |  |
|  | **United States—0.3%** | **United States—0.3%** | **United States—0.3%** |
| \* <br>| Laureate Education, Inc. <br>(Diversified Consumer Services)<br>| 93345 | &nbsp;&nbsp; 3143 |
|  | **Total Common Stocks—99.4%** <br>(cost $703,362)<br>|  | &nbsp;&nbsp; 1008320 |
|  | ***Preferred Stocks*** | ***Preferred Stocks*** | ***Preferred Stocks*** |
|  | ***Emerging Asia—0.0%*** |  |  |
|  | **India—0.0%** | **India—0.0%** | **India—0.0%** |
| \* <br>| TVS Motor Company Limited <br>(Automobiles)<br>| 405972 | &nbsp;&nbsp; 45 |
|  | **Total Preferred Stocks—0.0%** <br>(cost $0)<br>|  | &nbsp;&nbsp; 45 |

---

---

| | | |
|:---|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, <br> 1.150% dated 12/31/25, due 01/02/26, <br> repurchase price $11,306, <br> collateralized by U.S. Treasury Bond, <br> 4.625%, due 11/15/2055, valued at <br> $11,532<br>| $11305 | &nbsp;&nbsp; 11305 |
| **Total Repurchase Agreements—1.1%** <br>(cost $11,305)<br>|  | &nbsp;&nbsp; 11305 |
| **Total Investments—100.5%** <br>(cost $714,667)<br>|  | &nbsp;&nbsp; 1019670 |
| **Liabilities, plus cash and** <br>**other assets—(0.5)%**<br>|  | &nbsp;&nbsp; (5184)<br>|
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $1014486 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company <br> REIT Real Estate Investment Trust

\* Non-income producing security <br> † U.S. listed foreign security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**43**

*William Blair Funds*

------

**Emerging Markets Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $1003396 | &nbsp;&nbsp; $4924 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1008320 |
| Repurchase Agreements |  | &nbsp;&nbsp; 11305 | &nbsp;&nbsp; — | &nbsp;&nbsp; 11305 |
| Preferred Stocks |  | &nbsp;&nbsp; 45 | &nbsp;&nbsp; — | &nbsp;&nbsp; 45 |
| **Total Investments in Securities** | $1003396 | &nbsp;&nbsp; $16274 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $1019670 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**44**

*Annual*

------

**Emerging Markets ex China Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Emerging Asia—73.2%*** |  |  |
|  | **India—18.3%** | **India—18.3%** | **India—18.3%** |
|  | Bajaj Finance Limited <br>(Consumer Finance)<br>| 69777 | &nbsp;&nbsp; $766 |
|  | Bharat Electronics Ltd. <br>(Aerospace & Defense)<br>| 133458 | &nbsp;&nbsp; 593 |
|  | Bharti Airtel Ltd. <br>(Wireless Telecommunication Services)<br>| 47548 | &nbsp;&nbsp; 1115 |
|  | Coforge Limited <br>(IT Services)<br>| 9808 | &nbsp;&nbsp; 182 |
|  | Cummins India Ltd. <br>(Machinery)<br>| 5540 | &nbsp;&nbsp; 273 |
|  | Eicher Motors Limited <br>(Automobiles)<br>| 4433 | &nbsp;&nbsp; 361 |
|  | GE Vernova T&D India Ltd. <br>(Electrical Equipment)<br>| 11437 | &nbsp;&nbsp; 398 |
|  | HDFC Asset Management Co. Ltd. <br>(Capital Markets)<br>| 10123 | &nbsp;&nbsp; 301 |
|  | HDFC Bank Ltd. <br>(Banks)<br>| 114256 | &nbsp;&nbsp; 1262 |
|  | Hindustan Aeronautics Ltd. <br>(Aerospace & Defense)<br>| 8035 | &nbsp;&nbsp; 392 |
|  | Hitachi Energy India Ltd. <br>(Electrical Equipment)<br>| 1011 | &nbsp;&nbsp; 205 |
|  | ICICI Bank Ltd. <br>(Banks)<br>| 69931 | &nbsp;&nbsp; 1045 |
|  | Indian Hotels Co. Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 46389 | &nbsp;&nbsp; 381 |
|  | KFin Technologies Ltd. <br>(Capital Markets)<br>| 13646 | &nbsp;&nbsp; 164 |
|  | L&T Finance Limited <br>(Financial Services)<br>| 56860 | &nbsp;&nbsp; 200 |
|  | Macrotech Developers Ltd. <br>(Real Estate Management & <br> Development)<br>| 3221 | &nbsp;&nbsp; 38 |
|  | Mahindra & Mahindra Ltd. <br>(Automobiles)<br>| 13550 | &nbsp;&nbsp; 560 |
|  | Max Healthcare Institute Ltd. <br>(Health Care Providers & Services)<br>| 25182 | &nbsp;&nbsp; 293 |
|  | Reliance Industries Ltd. <br>(Oil, Gas & Consumable Fuels)<br>| 38822 | &nbsp;&nbsp; 678 |
|  | Shriram Finance Limited <br>(Consumer Finance)<br>| 19697 | &nbsp;&nbsp; 218 |
|  | TVS Motor Co. Ltd. <br>(Automobiles)<br>| 9828 | &nbsp;&nbsp; 407 |
|  | UNO Minda Ltd. <br>(Auto Components)<br>| 13669 | &nbsp;&nbsp; 194 |
| \* <br>| Vishal Mega Mart Limited <br>(Broadline Retail)<br>| 105624 | &nbsp;&nbsp; 160 |
| \* <br>| Zomato Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 115912 | &nbsp;&nbsp; 359 |
|  |  |  | &nbsp;&nbsp; 10545 |
|  | **Indonesia—3.5%** | **Indonesia—3.5%** | **Indonesia—3.5%** |
|  | Bank Central Asia Tbk. PT <br>(Banks)<br>| 1132200 | &nbsp;&nbsp; 548 |
| \* <br>| Grab Holdings Limited <br>(Road & Rail)<br>| 75815 | &nbsp;&nbsp; 378 |
| \* <br>| Sea Ltd.—ADR <br>(Entertainment)<br>| 8338 | &nbsp;&nbsp; 1064 |
|  |  |  | &nbsp;&nbsp; 1990 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **Malaysia—0.6%** | **Malaysia—0.6%** | **Malaysia—0.6%** |
|  | 99 Speed Mart Retail Holdings Bhd. <br>(Consumer Staples Distribution & Retail)<br>| 343400 | &nbsp;&nbsp; $322 |
|  | **Philippines—0.9%** | **Philippines—0.9%** | **Philippines—0.9%** |
|  | International Container Terminal Services, <br> Inc. <br>(Transportation Infrastructure)<br>| 57000 | &nbsp;&nbsp; 549 |
|  | **South Korea—19.7%** | **South Korea—19.7%** | **South Korea—19.7%** |
|  | Hanwha Aerospace Co. Ltd. <br>(Aerospace & Defense)<br>| 965 | &nbsp;&nbsp; 630 |
| \* <br>| Hanwha Engine <br>(Machinery)<br>| 5573 | &nbsp;&nbsp; 166 |
|  | HD Hyundai Electric Co. Ltd. <br>(Electrical Equipment)<br>| 1231 | &nbsp;&nbsp; 661 |
|  | HD Hyundai Heavy Industries Co., Ltd. <br>(Machinery)<br>| 975 | &nbsp;&nbsp; 345 |
|  | HD Hyundai Marine Solution Co., Ltd. <br>(Machinery)<br>| 1770 | &nbsp;&nbsp; 238 |
|  | Hyosung Heavy Industries Corporation <br>(Electrical Equipment)<br>| 320 | &nbsp;&nbsp; 396 |
|  | Hyundai Rotem Company <br>(Machinery)<br>| 2017 | &nbsp;&nbsp; 263 |
|  | IsuPetasys Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 2696 | &nbsp;&nbsp; 223 |
|  | Kakao Corp. <br>(Interactive Media & Services)<br>| 9002 | &nbsp;&nbsp; 376 |
| \* <br>| Samsung Biologics Co. Ltd. <br>(Life Sciences Tools & Services)<br>| 261 | &nbsp;&nbsp; 307 |
|  | Samsung Electro-Mechanics Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 1488 | &nbsp;&nbsp; 263 |
|  | Samsung Electronics Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 42530 | &nbsp;&nbsp; 3540 |
|  | Samyangfoods Co., Ltd <br>(Food Products)<br>| 228 | &nbsp;&nbsp; 195 |
|  | SK Hynix, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 6754 | &nbsp;&nbsp; 3052 |
| \* <br>| SK Square Co., Ltd. <br>(Industrial Conglomerates)<br>| 2755 | &nbsp;&nbsp; 704 |
|  |  |  | &nbsp;&nbsp; 11359 |
|  | **Taiwan—29.4%** | **Taiwan—29.4%** | **Taiwan—29.4%** |
|  | Accton Technology Corp. <br>(Communications Equipment)<br>| 20000 | &nbsp;&nbsp; 754 |
|  | Asia Vital Components Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 10000 | &nbsp;&nbsp; 481 |
|  | Bizlink Holding Inc. <br>(Electrical Equipment)<br>| 9079 | &nbsp;&nbsp; 439 |
|  | Chroma ATE, Inc. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 33000 | &nbsp;&nbsp; 814 |
|  | Delta Electronics, Inc. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 36000 | &nbsp;&nbsp; 1103 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**45**

*William Blair Funds*

------

**Emerging Markets ex China Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **Taiwan—(continued)** | **Taiwan—(continued)** | **Taiwan—(continued)** |
|  | Elite Material Co. Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 11000 | &nbsp;&nbsp; $576 |
|  | Gold Circuit Electronics Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 18000 | &nbsp;&nbsp; 394 |
|  | Hon Hai Precision Industry Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 135000 | &nbsp;&nbsp; 991 |
|  | Jentech Precision Industrial Co. Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 3000 | &nbsp;&nbsp; 262 |
|  | King Slide Works Co., Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 3000 | &nbsp;&nbsp; 358 |
|  | Taiwan Semiconductor Manufacturing Co. <br> Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 103000 | &nbsp;&nbsp; 5081 |
|  | Taiwan Semiconductor Manufacturing Co. <br> Ltd.—ADR <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 15352 | &nbsp;&nbsp; 4665 |
|  | Wiwynn Corp. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 7000 | &nbsp;&nbsp; 999 |
|  |  |  | &nbsp;&nbsp; 16917 |
|  | **Thailand—0.8%** | **Thailand—0.8%** | **Thailand—0.8%** |
| \* <br>| Fabrinet <br>(Electronic Equipment, Instruments & <br> Components)<br>| 1051 | &nbsp;&nbsp; 479 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 42161 |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—12.8%*** |  |  |
|  | **Greece—2.0%** | **Greece—2.0%** | **Greece—2.0%** |
|  | Eurobank S.A. <br>(Banks)<br>| 137485 | &nbsp;&nbsp; 554 |
|  | Optima bank SA <br>(Banks)<br>| 23315 | &nbsp;&nbsp; 211 |
|  | Piraeus Bank S.A. <br>(Banks)<br>| 48100 | &nbsp;&nbsp; 384 |
|  |  |  | &nbsp;&nbsp; 1149 |
|  | **Hungary—1.1%** | **Hungary—1.1%** | **Hungary—1.1%** |
|  | OTP Bank Nyrt. PLC <br>(Banks)<br>| 5977 | &nbsp;&nbsp; 641 |
|  | **Poland—1.1%** | **Poland—1.1%** | **Poland—1.1%** |
| \* <br>| Benefit Systems SA <br>(Professional Services)<br>| 255 | &nbsp;&nbsp; 249 |
|  | PKO Bank Polski S.A. <br>(Banks)<br>| 16712 | &nbsp;&nbsp; 397 |
|  |  |  | &nbsp;&nbsp; 646 |
|  | **Saudi Arabia—0.4%** | **Saudi Arabia—0.4%** | **Saudi Arabia—0.4%** |
| \* <br>| Rasan Information Technology Company <br>(Insurance)<br>| 6135 | &nbsp;&nbsp; 190 |
|  | **South Africa—4.7%** | **South Africa—4.7%** | **South Africa—4.7%** |
|  | Capitec Bank Holdings Ltd. <br>(Banks)<br>| 3224 | &nbsp;&nbsp; 809 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—(continued)***<br>|  |  |
|  | **South Africa—(continued)** | **South Africa—(continued)** | **South Africa—(continued)** |
|  | MTN Group Limited <br>(Wireless Telecommunication Services)<br>| 28991 | &nbsp;&nbsp; $297 |
|  | Naspers Limited <br>(Broadline Retail)<br>| 15539 | &nbsp;&nbsp; 1036 |
|  | OUTsurance Group Ltd. <br>(Insurance)<br>| 54517 | &nbsp;&nbsp; 236 |
|  | Pan African Resources PLC <br>(Metals & Mining)<br>| 209631 | &nbsp;&nbsp; 342 |
|  |  |  | &nbsp;&nbsp; 2720 |
|  | **Turkey—0.7%** | **Turkey—0.7%** | **Turkey—0.7%** |
|  | ASELSAN Elektronik Sanayi ve Ticaret <br> A.S. <br>(Aerospace & Defense)<br>| 75240 | &nbsp;&nbsp; 406 |
|  | **United Arab Emirates—2.8%** | **United Arab Emirates—2.8%** | **United Arab Emirates—2.8%** |
|  | Abu Dhabi Islamic Bank PJSC <br>(Banks)<br>| 44399 | &nbsp;&nbsp; 251 |
|  | Aldar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 120276 | &nbsp;&nbsp; 285 |
|  | Emaar Properties PJSC <br>(Real Estate Management & <br> Development)<br>| 97356 | &nbsp;&nbsp; 372 |
|  | Emirates NBD Bank PJSC <br>(Banks)<br>| 34634 | &nbsp;&nbsp; 262 |
|  | Parkin Company PJSC <br>(Commercial Services & Supplies)<br>| 98000 | &nbsp;&nbsp; 152 |
|  | Salik Co. PJSC <br>(Transportation Infrastructure)<br>| 156624 | &nbsp;&nbsp; 271 |
|  |  |  | &nbsp;&nbsp; 1593 |
|  | **Total Emerging Europe, Mid-East, Africa** |  | &nbsp;&nbsp; 7345 |
|  | ***Emerging Latin America—11.3%*** |  |  |
|  | **Brazil—6.5%** | **Brazil—6.5%** | **Brazil—6.5%** |
| \* <br>| Banco BTG Pactual SA <br>(Capital Markets)<br>| 67000 | &nbsp;&nbsp; 643 |
|  | Companhia de Saneamento Basico do <br> Estado de Sao Paulo - SABESP <br>(Water Utilities)<br>| 7722 | &nbsp;&nbsp; 188 |
|  | Cury Construtora e Incorporadora SA <br>(Household Durables)<br>| 50500 | &nbsp;&nbsp; 297 |
|  | Embraer S.A. <br>(Aerospace & Defense)<br>| 18300 | &nbsp;&nbsp; 296 |
|  | Itau Unibanco Holding SA—ADR <br>(Banks)<br>| 91391 | &nbsp;&nbsp; 654 |
| \* <br>| MercadoLibre, Inc. <br>(Broadline Retail)<br>| 560 | &nbsp;&nbsp; 1128 |
| \* <br>| NU Holdings Ltd.<sup>†</sup> <br>(Banks)<br>| 32596 | &nbsp;&nbsp; 546 |
|  |  |  | &nbsp;&nbsp; 3752 |
|  | **Chile—1.9%** | **Chile—1.9%** | **Chile—1.9%** |
|  | Antofagasta PLC <br>(Metals & Mining)<br>| 9629 | &nbsp;&nbsp; 426 |
|  | Banco de Chile <br>(Banks)<br>| 1506754 | &nbsp;&nbsp; 291 |
|  | Falabella S.A. <br>(Broadline Retail)<br>| 50088 | &nbsp;&nbsp; 349 |
|  |  |  | &nbsp;&nbsp; 1066 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**46**

*Annual*

------

**Emerging Markets ex China Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| &nbsp;&nbsp; **Shares or**<br> **Principal**<br> **Amount** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Latin America—(continued)*** |  |  |
|  | **Mexico—1.5%** | **Mexico—1.5%** | **Mexico—1.5%** |
| \* <br>| BBB Foods, Inc. <sup>†</sup> <br>(Consumer Staples Distribution & Retail)<br>| 6089 | &nbsp;&nbsp; $204 |
|  | Gentera S.A.B. de C.V. <br>(Consumer Finance)<br>| 99100 | &nbsp;&nbsp; 253 |
|  | Grupo Financiero Banorte S.A.B. de C.V. <br>(Banks)<br>| 44500 | &nbsp;&nbsp; 412 |
|  |  |  | &nbsp;&nbsp; 869 |
|  | **Panama—0.4%** | **Panama—0.4%** | **Panama—0.4%** |
|  | Banco Latinoamericano de Comercio <br> Exterior, S.A. <br>(Financial Services)<br>| 5228 | &nbsp;&nbsp; 233 |
|  | **Peru—1.0%** | **Peru—1.0%** | **Peru—1.0%** |
|  | Credicorp Ltd. <br>(Banks)<br>| 1977 | &nbsp;&nbsp; 567 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 6487 |
|  | ***Western Hemisphere—1.1%*** |  |  |
|  | **United States—1.1%** | **United States—1.1%** | **United States—1.1%** |
|  | Aura Minerals Inc. <br>(Metals & Mining)<br>| 6998 | &nbsp;&nbsp; 353 |
| \* <br>| Laureate Education, Inc. <br>(Diversified Consumer Services)<br>| 9070 | &nbsp;&nbsp; 305 |
|  | **Total Western Hemisphere** |  | &nbsp;&nbsp; 658 |
|  | ***Europe Ex-U.K.—0.5%*** |  |  |
|  | **Luxembourg—0.5%** | **Luxembourg—0.5%** | **Luxembourg—0.5%** |
|  | Millicom International Cellular S.A. <br>(Wireless Telecommunication Services)<br>| 5059 | &nbsp;&nbsp; 281 |
|  | **Total Common Stocks—98.9%** <br>(cost $43,071)<br>|  | &nbsp;&nbsp; 56932 |
|  | ***Preferred Stocks*** | ***Preferred Stocks*** | ***Preferred Stocks*** |
|  | ***Emerging Asia—0.0%*** |  |  |
|  | **India—0.0%** | **India—0.0%** | **India—0.0%** |
| \* <br>| TVS Motor Company Limited <br>(Automobiles)<br>| 37580 | &nbsp;&nbsp; 4 |
|  | **Total Preferred Stocks—0.0%** <br>(cost $0)<br>|  | &nbsp;&nbsp; 4 |

---

---

| | |
|:---|:---|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $290, collateralized by U.S. Treasury <br> Inflation – Indexed Bond, 2.125%, due <br> 02/15/2054, valued at $296<br>| &nbsp;&nbsp; 290 |
| **Total Repurchase Agreements—0.5%** <br>(cost $290)<br>| &nbsp;&nbsp; 290 |
| **Total Investments—99.4%** <br>(cost $43,361)<br>| &nbsp;&nbsp; 57226 |
| **Cash and other assets,** <br>**less liabilities—0.6%**<br>| &nbsp;&nbsp; 363 |
| **Net Assets—100.0%** | &nbsp;&nbsp; $57589 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company

\* Non-income producing security <br> † U.S. listed foreign security

See accompanying Notes to Financial Statements.

*December 31, 2025*

**47**

*William Blair Funds*

------

**Emerging Markets ex China Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $56453 | &nbsp;&nbsp; $479 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $56932 |
| Repurchase Agreements |  | &nbsp;&nbsp; 290 | &nbsp;&nbsp; — | &nbsp;&nbsp; 290 |
| Preferred Stocks |  | &nbsp;&nbsp; 4 | &nbsp;&nbsp; — | &nbsp;&nbsp; 4 |
| **Total Investments in Securities** | $56453 | &nbsp;&nbsp; $773 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $57226 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**48**

*Annual*

------

**Emerging Markets Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Emerging Asia—62.8%*** |  |  |
|  | **China—9.3%** | **China—9.3%** | **China—9.3%** |
|  | Atour Lifestyle Holdings Ltd.—ADR <br>(Hotels, Restaurants & Leisure)<br>| 91773 | &nbsp;&nbsp; $3616 |
|  | Guizhou Chanhen Chemical Corporation <br>(Chemicals)<br>| 645300 | &nbsp;&nbsp; 3391 |
|  | Harbin Electric Company Limited <br>(Electrical Equipment)<br>| 748000 | &nbsp;&nbsp; 1598 |
|  | Huaming Power Equipment Co. Ltd. <br>(Machinery)<br>| 446400 | &nbsp;&nbsp; 1602 |
|  | Jones Tech PLC <br>(Electronic Equipment, Instruments & <br> Components)<br>| 266700 | &nbsp;&nbsp; 1882 |
|  | Neway Valve (Suzhou) Co., Ltd. <br>(Machinery)<br>| 980600 | &nbsp;&nbsp; 7306 |
|  | Shanghai Conant Optical Co., Ltd. <br>(Health Care Equipment & Supplies)<br>| 311000 | &nbsp;&nbsp; 2158 |
| \* <br>| VNET Group, Inc.—ADR <br>(IT Services)<br>| 317775 | &nbsp;&nbsp; 2688 |
| \* <br>| WuXi XDC Cayman Inc. <br>(Life Sciences Tools & Services)<br>| 251000 | &nbsp;&nbsp; 1959 |
|  | Yutong Bus Co. Ltd. <br>(Machinery)<br>| 1122500 | &nbsp;&nbsp; 5262 |
|  | Zhejiang Sanmei Chemical Industry Co., <br> Ltd. <br>(Chemicals)<br>| 313400 | &nbsp;&nbsp; 2728 |
|  |  |  | &nbsp;&nbsp; 34190 |
|  | **India—22.3%** | **India—22.3%** | **India—22.3%** |
|  | 360 ONE WAM Ltd. <br>(Capital Markets)<br>| 150803 | &nbsp;&nbsp; 1995 |
|  | Allied Blenders and Distillers Limited <br>(Beverages)<br>| 308434 | &nbsp;&nbsp; 2106 |
|  | Aster DM Healthcare Limited <br>(Health Care Providers & Services)<br>| 135597 | &nbsp;&nbsp; 929 |
| \* <br>| Cartrade Tech Limited <br>(Specialty Retail)<br>| 97953 | &nbsp;&nbsp; 3079 |
|  | Chalet Hotels Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 56954 | &nbsp;&nbsp; 551 |
|  | City Union Bank Limited <br>(Banks)<br>| 842065 | &nbsp;&nbsp; 2711 |
|  | Fortis Healthcare Limited <br>(Health Care Providers & Services)<br>| 294462 | &nbsp;&nbsp; 2899 |
|  | GE Vernova T&D India Ltd. <br>(Electrical Equipment)<br>| 219688 | &nbsp;&nbsp; 7655 |
| \* <br>| GMR Airports Infrastructure Ltd. <br>(Transportation Infrastructure)<br>| 1922530 | &nbsp;&nbsp; 2229 |
|  | Hindustan Copper Limited <br>(Metals & Mining)<br>| 374650 | &nbsp;&nbsp; 2160 |
|  | Hindustan Zinc Limited <br>(Metals & Mining)<br>| 290224 | &nbsp;&nbsp; 1977 |
|  | Hitachi Energy India Ltd. <br>(Electrical Equipment)<br>| 1818 | &nbsp;&nbsp; 369 |
|  | Indian Bank <br>(Banks)<br>| 318541 | &nbsp;&nbsp; 2966 |
|  | Karur Vysya Bank Ltd. <br>(Banks)<br>| 2075358 | &nbsp;&nbsp; 6071 |
|  | Laurus Labs Limited <br>(Pharmaceuticals)<br>| 363917 | &nbsp;&nbsp; 4494 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **India—(continued)** | **India—(continued)** | **India—(continued)** |
| \* <br>| Multi Commodity Exchange of India <br> Limited <br>(Capital Markets)<br>| 22187 | &nbsp;&nbsp; $2746 |
|  | Muthoot Finance Limited <br>(Consumer Finance)<br>| 107015 | &nbsp;&nbsp; 4536 |
|  | National Aluminium Company Limited <br>(Metals & Mining)<br>| 669986 | &nbsp;&nbsp; 2346 |
|  | Neuland Laboratories Limited <br>(Pharmaceuticals)<br>| 5284 | &nbsp;&nbsp; 894 |
|  | Nippon Life India Asset Management <br> Limited <br>(Capital Markets)<br>| 444320 | &nbsp;&nbsp; 4360 |
|  | Pricol Limited <br>(Auto Components)<br>| 177903 | &nbsp;&nbsp; 1302 |
|  | Quality Power Electrical Equipments <br> Limited <br>(Electrical Equipment)<br>| 297104 | &nbsp;&nbsp; 2410 |
|  | Radico Khaitan Ltd. <br>(Beverages)<br>| 102262 | &nbsp;&nbsp; 3749 |
| \* <br>| SAI Life Sciences Limited <br>(Life Sciences Tools & Services)<br>| 209591 | &nbsp;&nbsp; 2120 |
|  | Shaily Engineering Plastics Limited <br>(Machinery)<br>| 123328 | &nbsp;&nbsp; 3107 |
|  | Skipper Ltd. <br>(Construction & Engineering)<br>| 267128 | &nbsp;&nbsp; 1299 |
| \* <br>| Tbo Tek Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 93818 | &nbsp;&nbsp; 1745 |
|  | TD Power Systems Limited <br>(Electrical Equipment)<br>| 309049 | &nbsp;&nbsp; 2407 |
|  | The Federal Bank Limited <br>(Banks)<br>| 676977 | &nbsp;&nbsp; 2011 |
| \* <br>| V2 Retail Limited <br>(Specialty Retail)<br>| 72811 | &nbsp;&nbsp; 1980 |
| \* <br>| Vishal Mega Mart Limited <br>(Broadline Retail)<br>| 1782237 | &nbsp;&nbsp; 2707 |
|  |  |  | &nbsp;&nbsp; 81910 |
|  | **Malaysia—3.2%** | **Malaysia—3.2%** | **Malaysia—3.2%** |
|  | 99 Speed Mart Retail Holdings Bhd. <br>(Consumer Staples Distribution & <br> Retail)<br>| 5491800 | &nbsp;&nbsp; 5156 |
|  | Kelington Group Berhad <br>(Construction & Engineering)<br>| 1251900 | &nbsp;&nbsp; 1604 |
|  | Southern Cable Group Berhad <br>(Electrical Equipment)<br>| 6113300 | &nbsp;&nbsp; 3450 |
|  | Sunway Construction Group Berhad <br>(Construction & Engineering)<br>| 1041300 | &nbsp;&nbsp; 1453 |
|  |  |  | &nbsp;&nbsp; 11663 |
|  | **Pakistan—1.9%** | **Pakistan—1.9%** | **Pakistan—1.9%** |
|  | Lucky Cement Limited <br>(Construction Materials)<br>| 1829650 | &nbsp;&nbsp; 3120 |
|  | Meezan Bank Limited <br>(Banks)<br>| 1827194 | &nbsp;&nbsp; 2900 |
|  | United Bank Limited <br>(Banks)<br>| 625103 | &nbsp;&nbsp; 946 |
|  |  |  | &nbsp;&nbsp; 6966 |
|  | **South Korea—10.7%** | **South Korea—10.7%** | **South Korea—10.7%** |
| \* <br>| APR Co.,Ltd. <br>(Personal Care Products)<br>| 7931 | &nbsp;&nbsp; 1272 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**49**

*William Blair Funds*

------

**Emerging Markets Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **South Korea—(continued)** | **South Korea—(continued)** | **South Korea—(continued)** |
|  | BNK Financial Group, Inc. <br>(Banks)<br>| 602460 | &nbsp;&nbsp; $6637 |
|  | Hankuk Carbon Co., Ltd. <br>(Chemicals)<br>| 80763 | &nbsp;&nbsp; 1674 |
|  | Hansol Chemical Co., Ltd. <br>(Chemicals)<br>| 10451 | &nbsp;&nbsp; 1651 |
| \* <br>| Hanwha Engine <br>(Machinery)<br>| 94664 | &nbsp;&nbsp; 2822 |
| \* <br>| HD-Hyundai Marine Engine Co., Ltd. <br>(Machinery)<br>| 47916 | &nbsp;&nbsp; 2977 |
|  | IsuPetasys Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 21395 | &nbsp;&nbsp; 1770 |
|  | JB Financial Group Co. Ltd. <br>(Banks)<br>| 378482 | &nbsp;&nbsp; 6739 |
|  | Korea Investment Holdings Co., Ltd. <br>(Capital Markets)<br>| 36922 | &nbsp;&nbsp; 4145 |
|  | LS Electric Co., Ltd <br>(Electrical Equipment)<br>| 13589 | &nbsp;&nbsp; 4339 |
| \* <br>| Rainbow Robotics <br>(Machinery)<br>| 8867 | &nbsp;&nbsp; 2896 |
| \* <br>| Robotis Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 5982 | &nbsp;&nbsp; 1084 |
|  | Wonik IPS Co., Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 30367 | &nbsp;&nbsp; 1431 |
|  |  |  | &nbsp;&nbsp; 39437 |
|  | **Taiwan—15.1%** | **Taiwan—15.1%** | **Taiwan—15.1%** |
|  | Acter Group Corporation Limited <br>(Construction & Engineering)<br>| 64000 | &nbsp;&nbsp; 1591 |
|  | AP Memory Technology Corp. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 73000 | &nbsp;&nbsp; 1041 |
|  | ASPEED Technology, Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 23000 | &nbsp;&nbsp; 5314 |
|  | AURAS Technology Co. Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 37000 | &nbsp;&nbsp; 1189 |
|  | Bizlink Holding Inc. <br>(Electrical Equipment)<br>| 87047 | &nbsp;&nbsp; 4211 |
|  | Chenbro Micom Co., Ltd. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 88000 | &nbsp;&nbsp; 2815 |
|  | Chroma ATE, Inc. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 128000 | &nbsp;&nbsp; 3157 |
|  | Fositek Corp. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 51000 | &nbsp;&nbsp; 2638 |
|  | Gold Circuit Electronics Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 106000 | &nbsp;&nbsp; 2318 |
|  | Hon. Precision, Inc <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 69313 | &nbsp;&nbsp; 7556 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **Taiwan—(continued)** | **Taiwan—(continued)** | **Taiwan—(continued)** |
|  | Innodisk Corp. <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 79000 | &nbsp;&nbsp; $1448 |
|  | Jentech Precision Industrial Co. Ltd. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 31000 | &nbsp;&nbsp; 2708 |
|  | L&K Engineering Co., Ltd. <br>(Commercial Services & Supplies)<br>| 74000 | &nbsp;&nbsp; 1300 |
|  | MPI Corporation <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 48000 | &nbsp;&nbsp; 3437 |
|  | Taichung Commercial Bank Company <br> Limited <br>(Banks)<br>| 5300287 | &nbsp;&nbsp; 3509 |
|  | Taiwan Union Technology Corporation <br>(Electronic Equipment, Instruments & <br> Components)<br>| 413000 | &nbsp;&nbsp; 6493 |
|  | Tripod Technology Corp. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 93000 | &nbsp;&nbsp; 940 |
|  | Universal Microwave Technology, Inc. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 176000 | &nbsp;&nbsp; 3803 |
|  |  |  | &nbsp;&nbsp; 55468 |
|  | **Thailand—0.3%** | **Thailand—0.3%** | **Thailand—0.3%** |
|  | Kiatnakin Phatra Bank Public Company <br> Limited <br>(Banks)<br>| 625900 | &nbsp;&nbsp; 1351 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 230985 |
|  | ***Emerging Latin America—18.3%*** |  |  |
|  | **Brazil—8.3%** | **Brazil—8.3%** | **Brazil—8.3%** |
|  | CPFL Energia S.A. <br>(Electric Utilities)<br>| 104900 | &nbsp;&nbsp; 1020 |
|  | Cury Construtora e Incorporadora SA <br>(Household Durables)<br>| 918200 | &nbsp;&nbsp; 5401 |
|  | Cyrela Brazil Realty SA Empreendimentos <br> e Participacoes <br>(Household Durables)<br>| 314300 | &nbsp;&nbsp; 1699 |
|  | Direcional Engenharia SA <br>(Household Durables)<br>| 2006400 | &nbsp;&nbsp; 5170 |
|  | EcoRodovias Infraestrutura e Logistica <br> S/A <br>(Transportation Infrastructure)<br>| 1023800 | &nbsp;&nbsp; 1981 |
|  | Grupo SBF SA <br>(Specialty Retail)<br>| 318300 | &nbsp;&nbsp; 753 |
|  | Inter & Co, Inc. <br>(Banks)<br>| 651818 | &nbsp;&nbsp; 5527 |
| \* <br>| Orizon Valorizacao de Residuos S.A. <br>(Commercial Services & Supplies)<br>| 317800 | &nbsp;&nbsp; 4055 |
|  | TOTVS SA <br>(Software)<br>| 370400 | &nbsp;&nbsp; 2844 |
|  | Vivara Participacoes SA <br>(Textiles, Apparel & Luxury Goods)<br>| 307800 | &nbsp;&nbsp; 1867 |
|  |  |  | &nbsp;&nbsp; 30317 |
|  | **Chile—3.6%** | **Chile—3.6%** | **Chile—3.6%** |
|  | Banco de Credito e Inversiones S.A <br>(Banks)<br>| 78541 | &nbsp;&nbsp; 5092 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**50**

*Annual*

------

**Emerging Markets Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Latin*** <br> ***America—(continued)***<br>|  |  |
|  | **Chile—(continued)** | **Chile—(continued)** | **Chile—(continued)** |
|  | Banco Itau Chile SA <br>(Banks)<br>| 11071 | &nbsp;&nbsp; $245 |
|  | Parque Arauco S.A. <br>(Real Estate Management & <br> Development)<br>| 1043034 | &nbsp;&nbsp; 3462 |
|  | Plaza S.A. <br>(Real Estate Management & <br> Development)<br>| 1221908 | &nbsp;&nbsp; 4321 |
|  |  |  | &nbsp;&nbsp; 13120 |
|  | **Mexico—4.1%** | **Mexico—4.1%** | **Mexico—4.1%** |
| \* <br>| BBB Foods, Inc. <sup>†</sup> <br>(Consumer Staples Distribution & <br> Retail)<br>| 103516 | &nbsp;&nbsp; 3457 |
|  | Gentera S.A.B. de C.V. <br>(Consumer Finance)<br>| 2269100 | &nbsp;&nbsp; 5791 |
| \* <br>| Industrias Penoles, S.A.B. de C.V. <br>(Metals & Mining)<br>| 111290 | &nbsp;&nbsp; 5846 |
|  |  |  | &nbsp;&nbsp; 15094 |
|  | **Panama—0.5%** | **Panama—0.5%** | **Panama—0.5%** |
|  | Banco Latinoamericano de Comercio <br> Exterior, S.A. <br>(Financial Services)<br>| 42619 | &nbsp;&nbsp; 1901 |
|  | **Peru—1.8%** | **Peru—1.8%** | **Peru—1.8%** |
|  | Hochschild Mining PLC <br>(Metals & Mining)<br>| 408778 | &nbsp;&nbsp; 2829 |
|  | Intercorp Financial Services Inc <br>(Banks)<br>| 90432 | &nbsp;&nbsp; 3831 |
|  |  |  | &nbsp;&nbsp; 6660 |
|  | **Total Emerging Latin America** |  | &nbsp;&nbsp; 67092 |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—11.3%*** |  |  |
|  | **Czech Republic—1.5%** | **Czech Republic—1.5%** | **Czech Republic—1.5%** |
|  | MONETA Money Bank, a. s. <br>(Banks)<br>| 596403 | &nbsp;&nbsp; 5611 |
|  | **Georgia—1.1%** | **Georgia—1.1%** | **Georgia—1.1%** |
|  | Lion Finance Group PLC <br>(Banks)<br>| 33312 | &nbsp;&nbsp; 4176 |
|  | **Greece—1.4%** | **Greece—1.4%** | **Greece—1.4%** |
|  | GEK TERNA Holdings S.A. <br>(Construction & Engineering)<br>| 60417 | &nbsp;&nbsp; 1805 |
|  | Optima bank SA <br>(Banks)<br>| 325891 | &nbsp;&nbsp; 2953 |
|  | Titan SA <br>(Construction Materials)<br>| 5333 | &nbsp;&nbsp; 329 |
|  |  |  | &nbsp;&nbsp; 5087 |
|  | **Kazakhstan—1.1%** | **Kazakhstan—1.1%** | **Kazakhstan—1.1%** |
|  | JSC Halyk Bank <br>(Banks)<br>| 42287 | &nbsp;&nbsp; 1266 |
|  | NAC Kazatomprom JSC <br>(Oil, Gas & Consumable Fuels)<br>| 48186 | &nbsp;&nbsp; 2689 |
|  |  |  | &nbsp;&nbsp; 3955 |
|  | **Morocco—0.3%** | **Morocco—0.3%** | **Morocco—0.3%** |
|  | Marsa Maroc SA <br>(Transportation Infrastructure)<br>| 12689 | &nbsp;&nbsp; 1322 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Europe, Mid-East,*** <br> ***Africa—(continued)***<br>|  |  |
|  | **Saudi Arabia—0.6%** | **Saudi Arabia—0.6%** | **Saudi Arabia—0.6%** |
| \* <br>| Rasan Information Technology Company <br>(Insurance)<br>| 67623 | &nbsp;&nbsp; $2089 |
|  | **South Africa—1.4%** | **South Africa—1.4%** | **South Africa—1.4%** |
|  | DRDGOLD Limited <br>(Metals & Mining)<br>| 471443 | &nbsp;&nbsp; 1490 |
|  | Pan African Resources PLC <br>(Metals & Mining)<br>| 2122390 | &nbsp;&nbsp; 3462 |
|  | Vukile Property Fund Limited <br>(Retail REITs)<br>| 34221 | &nbsp;&nbsp; 52 |
|  |  |  | &nbsp;&nbsp; 5004 |
|  | **Turkey—2.6%** | **Turkey—2.6%** | **Turkey—2.6%** |
|  | ASELSAN Elektronik Sanayi ve Ticaret <br> A.S. <br>(Aerospace & Defense)<br>| 1536870 | &nbsp;&nbsp; 8296 |
|  | Logo Yazilim Sanayi ve Ticaret A.S. <br>(Software)<br>| 335854 | &nbsp;&nbsp; 1178 |
|  |  |  | &nbsp;&nbsp; 9474 |
|  | **United Arab Emirates—1.3%** | **United Arab Emirates—1.3%** | **United Arab Emirates—1.3%** |
|  | Air Arabia PJSC <br>(Airlines)<br>| 2488977 | &nbsp;&nbsp; 3158 |
|  | Parkin Company PJSC <br>(Commercial Services & Supplies)<br>| 1152586 | &nbsp;&nbsp; 1786 |
|  |  |  | &nbsp;&nbsp; 4944 |
|  | **Total Emerging Europe, Mid-East,** <br> **Africa**<br>|  | &nbsp;&nbsp; 41662 |
|  | ***Western Hemisphere—3.9%*** |  |  |
|  | **Canada—1.1%** | **Canada—1.1%** | **Canada—1.1%** |
| \* <br>| Aris Mining Corporation <br>(Metals & Mining)<br>| 258604 | &nbsp;&nbsp; 4197 |
|  | **United States—2.8%** | **United States—2.8%** | **United States—2.8%** |
|  | Aura Minerals Inc. <br>(Metals & Mining)<br>| 70839 | &nbsp;&nbsp; 3572 |
| \* <br>| Laureate Education, Inc. <br>(Diversified Consumer Services)<br>| 195492 | &nbsp;&nbsp; 6582 |
|  |  |  | &nbsp;&nbsp; 10154 |
|  | **Total Western Hemisphere** |  | &nbsp;&nbsp; 14351 |
|  | ***United Kingdom—1.7%*** |  |  |
|  | Airtel Africa PLC <br>(Wireless Telecommunication Services)<br>| 1304672 | &nbsp;&nbsp; 6247 |
|  | **Total Common Stocks—98.0%** <br>(cost $301,047)<br>|  | &nbsp;&nbsp; 360337 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**51**

*William Blair Funds*

------

**Emerging Markets Small Cap Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| <br>**Issuer**<br>| &nbsp;&nbsp; **Principal**<br> **Amount** | <br>**Value**<br>|
| ***Repurchase Agreements*** | ***Repurchase Agreements*** | ***Repurchase Agreements*** |
| Fixed Income Clearing Corporation, 1.150% <br> dated 12/31/25, due 01/02/26, repurchase <br> price $1,630, collateralized by <br> U.S. Treasury Bond, 4.625%, due <br> 11/15/2055, valued at $1,662<br>| $1630 | &nbsp;&nbsp; $1630 |
| **Total Repurchase Agreements—0.4%** <br>(cost $1,630)<br>|  | &nbsp;&nbsp; 1630 |
| **Total Investments—98.4%** <br>(cost $302,677)<br>|  | &nbsp;&nbsp; 361967 |
| **Cash and other assets,** <br>**less liabilities—1.6%**<br>|  | &nbsp;&nbsp; 5816 |
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $367783 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company <br> REITs Real Estate Investment Trust

\* Non-income producing security <br> † U.S. listed foreign security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $358986 | &nbsp;&nbsp; $1351 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $360337 |
| Repurchase Agreements |  | &nbsp;&nbsp; 1630 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1630 |
| **Total Investments in Securities** | $358986 | &nbsp;&nbsp; $2981 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $361967 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**52**

*Annual*

------

**China Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks*** | ***Common Stocks*** | ***Common Stocks*** |
|  | ***Emerging Asia—95.6%*** |  |  |
|  | **China—95.6%** | **China—95.6%** | **China—95.6%** |
|  | Agricultural Bank of China Ltd. <br>(Banks)<br>| 61000 | &nbsp;&nbsp; $45 |
|  | Alibaba Group Holding Ltd. <br>(Broadline Retail)<br>| 11676 | &nbsp;&nbsp; 214 |
|  | Atour Lifestyle Holdings Ltd.—ADR <br>(Hotels, Restaurants & Leisure)<br>| 969 | &nbsp;&nbsp; 38 |
|  | Bank of Ningbo Co. Ltd. <br>(Banks)<br>| 6990 | &nbsp;&nbsp; 28 |
| \* <br>| Beijing Geekplus Technology Co., Ltd. <br>(Machinery)<br>| 6000 | &nbsp;&nbsp; 17 |
| \* <br>| BeOne Medicines Ltd <br>(Biotechnology)<br>| 700 | &nbsp;&nbsp; 16 |
|  | BYD Company Limited <br>(Automobiles)<br>| 1100 | &nbsp;&nbsp; 15 |
|  | China Life Insurance Company Limited <br>(Insurance)<br>| 7000 | &nbsp;&nbsp; 25 |
|  | China Merchants Bank Co. Ltd. <br>(Banks)<br>| 7000 | &nbsp;&nbsp; 48 |
|  | CMOC Group Limited <br>(Metals & Mining)<br>| 9000 | &nbsp;&nbsp; 22 |
|  | Contemporary Amperex Technology Co. Ltd. <br>(Electrical Equipment)<br>| 1340 | &nbsp;&nbsp; 71 |
|  | East Money Information Co.,Ltd. <br>(Capital Markets)<br>| 7200 | &nbsp;&nbsp; 24 |
|  | Eastroc Beverage Group Co. Ltd. <br>(Beverages)<br>| 790 | &nbsp;&nbsp; 30 |
|  | Eoptolink Technology Inc., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 1040 | &nbsp;&nbsp; 64 |
|  | Foxconn Industrial Internet Co. Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 5700 | &nbsp;&nbsp; 51 |
|  | Fuyao Glass Industry Group Co. Ltd. <br>(Auto Components)<br>| 5000 | &nbsp;&nbsp; 43 |
|  | GigaDevice Semiconductor Inc. <br>(Semiconductors & Semiconductor <br> Equipment)<br>| 700 | &nbsp;&nbsp; 22 |
|  | Hansoh Pharmaceutical Group Company <br> Limited <br>(Pharmaceuticals)<br>| 4000 | &nbsp;&nbsp; 19 |
|  | Huaming Power Equipment Co. Ltd. <br>(Machinery)<br>| 8200 | &nbsp;&nbsp; 30 |
|  | Industrial and Commercial Bank of China <br> Limited <br>(Banks)<br>| 45000 | &nbsp;&nbsp; 36 |
| \* <br>| Innovent Biologics, Inc. <br>(Biotechnology)<br>| 1500 | &nbsp;&nbsp; 15 |
|  | Jiangsu Hengli Hydraulic Co. Ltd. <br>(Machinery)<br>| 1200 | &nbsp;&nbsp; 19 |
|  | Jiangsu Hengrui Pharmaceuticals Co.,Ltd <br>(Pharmaceuticals)<br>| 3200 | &nbsp;&nbsp; 27 |
|  | Jones Tech PLC <br>(Electronic Equipment, Instruments & <br> Components)<br>| 2300 | &nbsp;&nbsp; 16 |
|  | Laopu Gold Co., Ltd. <br>(Textiles, Apparel & Luxury Goods)<br>| 300 | &nbsp;&nbsp; 24 |
|  | Mao Geping Cosmetics CO.,LTD. <br>(Personal Care Products)<br>| 1300 | &nbsp;&nbsp; 14 |

---

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Emerging Asia—(continued)*** |  |  |
|  | **China—(continued)** | **China—(continued)** | **China—(continued)** |
| \* <br>| Meitu, Inc. <br>(Interactive Media & Services)<br>| 26000 | &nbsp;&nbsp; $23 |
|  | NetEase, Inc. <br>(Entertainment)<br>| 2300 | &nbsp;&nbsp; 63 |
|  | PICC Property and Casualty Company Limited <br>(Insurance)<br>| 14000 | &nbsp;&nbsp; 30 |
|  | Pop Mart International Group Ltd. <br>(Specialty Retail)<br>| 1800 | &nbsp;&nbsp; 43 |
|  | Shanghai Chicmax Cosmetics Co., Ltd. <br>(Personal Care Products)<br>| 1800 | &nbsp;&nbsp; 17 |
|  | Shengyi Technology Co.,Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 4500 | &nbsp;&nbsp; 46 |
|  | Shenzhen Envicool Technology Co., Ltd. <br>(Machinery)<br>| 2000 | &nbsp;&nbsp; 31 |
|  | Shenzhen Inovance Technology Co. Ltd. <br>(Machinery)<br>| 4100 | &nbsp;&nbsp; 44 |
|  | Sieyuan Electric Co. Ltd. <br>(Electrical Equipment)<br>| 1800 | &nbsp;&nbsp; 40 |
|  | Tencent Holdings Ltd. <br>(Interactive Media & Services)<br>| 3900 | &nbsp;&nbsp; 300 |
|  | Trip.com Group Ltd. <br>(Hotels, Restaurants & Leisure)<br>| 700 | &nbsp;&nbsp; 50 |
|  | Victory Giant Technology (HuiZhou) Co., Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 700 | &nbsp;&nbsp; 29 |
|  | WUS Printed Circuit Kunshan Co. Ltd. <br>(Electronic Equipment, Instruments & <br> Components)<br>| 4200 | &nbsp;&nbsp; 44 |
|  | WuXi AppTec Co., Ltd. <br>(Life Sciences Tools & Services)<br>| 2100 | &nbsp;&nbsp; 27 |
| \* <br>| WuXi XDC Cayman Inc. <br>(Life Sciences Tools & Services)<br>| 2000 | &nbsp;&nbsp; 16 |
| \* <br>| Xiaomi Corporation <br>(Technology Hardware, Storage & <br> Peripherals)<br>| 7600 | &nbsp;&nbsp; 38 |
|  | Yutong Bus Co. Ltd. <br>(Machinery)<br>| 7100 | &nbsp;&nbsp; 33 |
| \* <br>| Zhejiang Leapmotor Technology Co., Ltd. <br>(Automobiles)<br>| 2300 | &nbsp;&nbsp; 14 |
|  | Zhongji Innolight Co. Ltd. <br>(Communications Equipment)<br>| 800 | &nbsp;&nbsp; 70 |
|  | Zijin Mining Group Company Limited <br>(Metals & Mining)<br>| 12000 | &nbsp;&nbsp; 55 |
|  | **Total Emerging Asia** |  | &nbsp;&nbsp; 1986 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**53**

*William Blair Funds*

------

**China Growth Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | <br>**Issuer**<br>| **Shares** | <br>**Value**<br>|
|  | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** | ***Common Stocks—(continued)*** |
|  | ***Asia Ex-Japan—3.0%*** |  |  |
|  | **Hong Kong—3.0%** | **Hong Kong—3.0%** | **Hong Kong—3.0%** |
| \* <br>| Futu Holdings Ltd.—ADR <br>(Capital Markets)<br>| 157 | &nbsp;&nbsp; $26 |
|  | Hong Kong Exchanges & Clearing Ltd. <br>(Capital Markets)<br>| 700 | &nbsp;&nbsp; 36 |
|  | **Total Asia Ex-Japan** |  | &nbsp;&nbsp; 62 |
|  | **Total Common Stocks—98.6%** <br>(cost $1,525)<br>|  | &nbsp;&nbsp; 2048 |
|  | **Total Investments—98.6%** <br>(cost $1,525)<br>|  | &nbsp;&nbsp; 2048 |
|  | **Cash and other assets,** <br>**less liabilities—1.4%**<br>|  | &nbsp;&nbsp; 30 |
|  | **Net Assets—100.0%** |  | &nbsp;&nbsp; $2078 |

---

------

ADR American Depositary Receipt <br> PLC Public Limited Company

\* Non-income producing security

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Common Stocks | $2048 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $2048 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**54**

*Annual*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal** <br>**Amount** | **Value** |
| **Foreign Government Bonds—62.6%** | **Foreign Government Bonds—62.6%** | **Foreign Government Bonds—62.6%** |
| **Angola—0.7%** | **Angola—0.7%** | **Angola—0.7%** |
| Angola Government International Bond, <br>9.125%, due 11/26/49<br>| $600 | &nbsp;&nbsp; $517 |
| **Argentina—3.8%** | **Argentina—3.8%** | **Argentina—3.8%** |
| Argentina Government Bond, <br>29.500%, due 5/30/30<br>| 200000 | &nbsp;&nbsp; 151 |
| Argentina Government International <br> Bond,<br>|  |  |
| 0.000%, due 12/15/35<sup>(a)</sup> | 500 | &nbsp;&nbsp; 51 |
| 0.000%, due 12/15/35<sup>(a)</sup> | $3480 | &nbsp;&nbsp; 89 |
| 1.000%, due 7/9/29 | 116 | &nbsp;&nbsp; 104 |
| 1.750%, due 7/9/30<sup>(a)</sup> | 992 | &nbsp;&nbsp; 845 |
| 4.250%, due 1/9/38<sup>(a)</sup> | 350 | &nbsp;&nbsp; 304 |
| 4.875%, due 7/9/41<sup>(a)</sup> | $700 | &nbsp;&nbsp; 484 |
| 5.000%, due 7/9/46<sup>(a)</sup> | 1021 | &nbsp;&nbsp; 727 |
|  |  | &nbsp;&nbsp; 2755 |
| **Bahrain—0.5%** | **Bahrain—0.5%** | **Bahrain—0.5%** |
| Bahrain Government International Bond, <br>5.250%, due 1/25/33<br>| 400 | &nbsp;&nbsp; 381 |
| **Barbados—0.3%** | **Barbados—0.3%** | **Barbados—0.3%** |
| Barbados Government International Bond, <br>8.000%, due 6/26/35<sup>(b)</sup><br>| 200 | &nbsp;&nbsp; 211 |
| **Benin—0.4%** | **Benin—0.4%** | **Benin—0.4%** |
| Benin Government International Bond, <br>6.875%, due 1/19/52<br>| 250 | &nbsp;&nbsp; 265 |
| **Bermuda—0.2%** | **Bermuda—0.2%** | **Bermuda—0.2%** |
| Bermuda Government International Bond, <br>3.375%, due 8/20/50<br>| $260 | &nbsp;&nbsp; 180 |
| **Bosnia & Herzegovina—0.4%** | **Bosnia & Herzegovina—0.4%** | **Bosnia & Herzegovina—0.4%** |
| Federation of Bosnia and Herzegovina, <br>5.500%, due 7/17/30<sup>(b)</sup><br>| 250 | &nbsp;&nbsp; 305 |
| **Brazil—2.3%** | **Brazil—2.3%** | **Brazil—2.3%** |
| Brazil Government International Bond, <br>4.750%, due 1/14/50<br>| $1350 | &nbsp;&nbsp; 981 |
| Brazil Letras do Tesouro Nacional, <br>0.010%, due 1/1/32<br>| 7400 | &nbsp;&nbsp; 626 |
| Brazil Notas do Tesouro Nacional, <br>10.000%, due 1/1/33<br>| 610 | &nbsp;&nbsp; 94 |
|  |  | &nbsp;&nbsp; 1701 |
| **Cameroon—0.1%** | **Cameroon—0.1%** | **Cameroon—0.1%** |
| Cameroon Government International <br> Bond, <br>5.950%, due 7/7/32<br>| 100 | &nbsp;&nbsp; 99 |
| **Chile—1.2%** | **Chile—1.2%** | **Chile—1.2%** |
| Chile Government International Bond, |  |  |
| 2.550%, due 7/27/33 | $420 | &nbsp;&nbsp; 364 |
| 3.250%, due 9/21/71 | 200 | &nbsp;&nbsp; 124 |
| Republic of Chile Peso Treasury Bonds, <br>4.700%, due 9/1/30<br>| 340000 | &nbsp;&nbsp; 370 |
|  |  | &nbsp;&nbsp; 858 |
| **Colombia—1.5%** | **Colombia—1.5%** | **Colombia—1.5%** |
| Colombia Government International <br> Bond,<br>|  |  |
| 4.125%, due 2/22/42 | $400 | &nbsp;&nbsp; 275 |
| 4.125%, due 5/15/51 | 450 | &nbsp;&nbsp; 278 |
| 6.500%, due 11/26/38 | 170 | &nbsp;&nbsp; 193 |

---

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** |
| **Colombia—(continued)** | **Colombia—(continued)** | **Colombia—(continued)** |
| Colombia Treasury Bond, |  |  |
| 7.000%, due 6/30/32 | 920000 | &nbsp;&nbsp; $182 |
| 7.250%, due 10/26/50 | 1300000 | &nbsp;&nbsp; 201 |
|  |  | &nbsp;&nbsp; 1129 |
| **Costa Rica—0.4%** | **Costa Rica—0.4%** | **Costa Rica—0.4%** |
| Costa Rica International Bond, <br>7.300%, due 11/13/54<br>| $250 | &nbsp;&nbsp; 280 |
| **Dominican Republic—2.5%** | **Dominican Republic—2.5%** | **Dominican Republic—2.5%** |
| Dominican Republic International Bond, |  |  |
| 4.875%, due 9/23/32 | 950 | &nbsp;&nbsp; 914 |
| 5.875%, due 10/28/35<sup>(b)</sup> | 150 | &nbsp;&nbsp; 150 |
| 5.875%, due 1/30/60 | 200 | &nbsp;&nbsp; 179 |
| 10.500%, due 3/15/37<sup>(b)</sup> | 33000 | &nbsp;&nbsp; 561 |
|  |  | &nbsp;&nbsp; 1804 |
| **Ecuador—2.0%** | **Ecuador—2.0%** | **Ecuador—2.0%** |
| Ecuador Government International Bond, |  |  |
| 0.010%, due 7/31/30 | $500 | &nbsp;&nbsp; 427 |
| 6.900%, due 7/31/30<sup>(a)</sup> | 400 | &nbsp;&nbsp; 395 |
| 6.900%, due 7/31/35<sup>(a)</sup> | 220 | &nbsp;&nbsp; 194 |
| 6.900%, due 7/31/40<sup>(a)</sup> | 600 | &nbsp;&nbsp; 466 |
|  |  | &nbsp;&nbsp; 1482 |
| **Egypt—3.3%** | **Egypt—3.3%** | **Egypt—3.3%** |
| Egypt Government International Bond, |  |  |
| 5.625%, due 4/16/30 | 250 | &nbsp;&nbsp; 293 |
| 5.800%, due 9/30/27 | $900 | &nbsp;&nbsp; 910 |
| 7.500%, due 2/16/61 | 800 | &nbsp;&nbsp; 697 |
| 8.150%, due 11/20/59 | 200 | &nbsp;&nbsp; 188 |
| Egypt Treasury Bill, <br>24.907%, due 3/17/26<br>| 16500 | &nbsp;&nbsp; 329 |
|  |  | &nbsp;&nbsp; 2417 |
| **El Salvador—0.8%** | **El Salvador—0.8%** | **El Salvador—0.8%** |
| El Salvador Government International <br> Bond,<br>|  |  |
| 0.250%, due 4/17/30<sup>(b)</sup> | $200 | &nbsp;&nbsp; 5 |
| 7.125%, due 1/20/50 | 615 | &nbsp;&nbsp; 565 |
|  |  | &nbsp;&nbsp; 570 |
| **Gabon—0.7%** | **Gabon—0.7%** | **Gabon—0.7%** |
| Gabon Government International Bond, <br>7.000%, due 11/24/31<br>| 650 | &nbsp;&nbsp; 497 |
| **Ghana—1.7%** | **Ghana—1.7%** | **Ghana—1.7%** |
| Ghana Government International Bond, |  |  |
| 0.000%, due 7/3/26<sup>(b)</sup> | 200 | &nbsp;&nbsp; 196 |
| 6.000%, due 7/3/29<sup>(a)</sup>,<sup>(b)</sup> | 260 | &nbsp;&nbsp; 256 |
| 6.000%, due 7/3/35<sup>(a)</sup> | 850 | &nbsp;&nbsp; 776 |
|  |  | &nbsp;&nbsp; 1228 |
| **Guatemala—1.6%** | **Guatemala—1.6%** | **Guatemala—1.6%** |
| Guatemala Government Bond, <br>6.550%, due 2/6/37<br>| 290 | &nbsp;&nbsp; 309 |
| Guatemala Government International <br> Bond,<br>|  |  |
| 3.700%, due 10/7/33 | 800 | &nbsp;&nbsp; 714 |
| 4.650%, due 10/7/41 | 200 | &nbsp;&nbsp; 172 |
|  |  | &nbsp;&nbsp; 1195 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**55**

*William Blair Funds*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** |
| **Hungary—2.2%** | **Hungary—2.2%** | **Hungary—2.2%** |
| Hungary Government International Bond, |  |  |
| 1.500%, due 11/17/50 | 200 | &nbsp;&nbsp; $117 |
| 3.125%, due 9/21/51 | $700 | &nbsp;&nbsp; 430 |
| 4.000%, due 4/28/51 | 350000 | &nbsp;&nbsp; 661 |
| 6.125%, due 5/22/28 | $400 | &nbsp;&nbsp; 415 |
|  |  | &nbsp;&nbsp; 1623 |
| **Indonesia—1.5%** | **Indonesia—1.5%** | **Indonesia—1.5%** |
| Indonesia Government International <br> Bond,<br>|  |  |
| 3.850%, due 10/15/30 | 200 | &nbsp;&nbsp; 197 |
| 4.750%, due 9/10/34 | 450 | &nbsp;&nbsp; 449 |
| 4.900%, due 4/16/36 | 200 | &nbsp;&nbsp; 200 |
| Perusahaan Penerbit SBSN Indonesia III, <br>4.700%, due 6/6/32<br>| 280 | &nbsp;&nbsp; 283 |
|  |  | &nbsp;&nbsp; 1129 |
| **Ivory Coast—0.4%** | **Ivory Coast—0.4%** | **Ivory Coast—0.4%** |
| Ivory Coast Government International <br> Bond,<br>|  |  |
| 6.625%, due 3/22/48 | 100 | &nbsp;&nbsp; 106 |
| 6.625%, due 3/22/48 | 200 | &nbsp;&nbsp; 213 |
|  |  | &nbsp;&nbsp; 319 |
| **Jamaica—0.9%** | **Jamaica—0.9%** | **Jamaica—0.9%** |
| Jamaica Government International Bond, |  |  |
| 8.000%, due 3/15/39 | $150 | &nbsp;&nbsp; 181 |
| 9.625%, due 11/3/30 | 67500 | &nbsp;&nbsp; 446 |
|  |  | &nbsp;&nbsp; 627 |
| **Kazakhstan—0.4%** | **Kazakhstan—0.4%** | **Kazakhstan—0.4%** |
| Kazakhstan Government Bond, <br>12.000%, due 2/22/31<br>| 175000 | &nbsp;&nbsp; 298 |
| **Kenya—0.3%** | **Kenya—0.3%** | **Kenya—0.3%** |
| Kenya Government International Bond, <br>6.300%, due 1/23/34<br>| $250 | &nbsp;&nbsp; 229 |
| **Kyrgyzstan—0.8%** | **Kyrgyzstan—0.8%** | **Kyrgyzstan—0.8%** |
| Kyrgyzstan Government Bond, <br>7.750%, due 6/3/30<sup>(b)</sup><br>| 550 | &nbsp;&nbsp; 566 |
| **Laos—0.3%** | **Laos—0.3%** | **Laos—0.3%** |
| Laos Government International Bond, <br>11.250%, due 11/12/30<sup>(b)</sup><br>| 200 | &nbsp;&nbsp; 202 |
| **Lebanon—0.9%** | **Lebanon—0.9%** | **Lebanon—0.9%** |
| Lebanon Government International Bond, |  |  |
| 5.800%, due 4/14/20<sup>(c)</sup> | 960 | &nbsp;&nbsp; 221 |
| 6.600%, due 11/27/26<sup>(c)</sup> | 580 | &nbsp;&nbsp; 133 |
| 6.850%, due 3/23/27<sup>(c)</sup> | 200 | &nbsp;&nbsp; 46 |
| 8.200%, due 5/17/33<sup>(c)</sup> | 1260 | &nbsp;&nbsp; 291 |
|  |  | &nbsp;&nbsp; 691 |
| **Mexico—1.5%** | **Mexico—1.5%** | **Mexico—1.5%** |
| Mexico Goverment Bond, <br>3.750%, due 4/19/71<br>| 1850 | &nbsp;&nbsp; 1091 |
| **Mongolia—0.6%** | **Mongolia—0.6%** | **Mongolia—0.6%** |
| Mongolia Government International <br> Bond, <br>3.500%, due 7/7/27<br>| 450 | &nbsp;&nbsp; 436 |
| **Morocco—0.2%** | **Morocco—0.2%** | **Morocco—0.2%** |
| Morocco Government International Bond, <br>4.000%, due 12/15/50<br>| 200 | &nbsp;&nbsp; 146 |

---

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** |
| **Nigeria—1.8%** | **Nigeria—1.8%** | **Nigeria—1.8%** |
| Central Bank of Nigeria Bond, <br>0.010%, due 2/10/26<br>| 510000 | &nbsp;&nbsp; $345 |
| Nigeria Government International Bond, |  |  |
| 7.143%, due 2/23/30 | $200 | &nbsp;&nbsp; 207 |
| 8.250%, due 9/28/51 | 350 | &nbsp;&nbsp; 343 |
| 8.631%, due 1/13/36<sup>(b)</sup> | 200 | &nbsp;&nbsp; 215 |
| 9.130%, due 1/13/46<sup>(b)</sup> | 200 | &nbsp;&nbsp; 215 |
|  |  | &nbsp;&nbsp; 1325 |
| **Oman—1.9%** | **Oman—1.9%** | **Oman—1.9%** |
| Oman Government International Bond, <br>6.750%, due 1/17/48<br>| 1250 | &nbsp;&nbsp; 1378 |
| **Pakistan—1.5%** | **Pakistan—1.5%** | **Pakistan—1.5%** |
| Pakistan Government International Bond, |  |  |
| 6.000%, due 4/8/26 | 200 | &nbsp;&nbsp; 200 |
| 6.875%, due 12/5/27 | 500 | &nbsp;&nbsp; 504 |
| 8.875%, due 4/8/51 | 200 | &nbsp;&nbsp; 196 |
| Pakistan Treasury Bills, <br>10.478%, due 10/29/26<br>| 55000 | &nbsp;&nbsp; 181 |
|  |  | &nbsp;&nbsp; 1081 |
| **Panama—1.3%** | **Panama—1.3%** | **Panama—1.3%** |
| Panama Government International Bond, |  |  |
| 2.252%, due 9/29/32 | $200 | &nbsp;&nbsp; 165 |
| 3.870%, due 7/23/60 | 830 | &nbsp;&nbsp; 548 |
| 4.500%, due 4/1/56 | 280 | &nbsp;&nbsp; 210 |
|  |  | &nbsp;&nbsp; 923 |
| **Paraguay—1.9%** | **Paraguay—1.9%** | **Paraguay—1.9%** |
| Paraguay Government International Bond, |  |  |
| 2.739%, due 1/29/33 | 250 | &nbsp;&nbsp; 223 |
| 5.400%, due 3/30/50 | 600 | &nbsp;&nbsp; 562 |
| 6.650%, due 3/4/55 | 200 | &nbsp;&nbsp; 218 |
| 8.500%, due 3/4/35<sup>(b)</sup> | 2500000 | &nbsp;&nbsp; 363 |
|  |  | &nbsp;&nbsp; 1366 |
| **Peru—0.9%** | **Peru—0.9%** | **Peru—0.9%** |
| Peru Government International Bond, |  |  |
| 2.783%, due 1/23/31 | $260 | &nbsp;&nbsp; 241 |
| 3.230%, due 7/28/21 | 400 | &nbsp;&nbsp; 218 |
| 3.600%, due 1/15/72 | 360 | &nbsp;&nbsp; 228 |
|  |  | &nbsp;&nbsp; 687 |
| **Philippines—1.1%** | **Philippines—1.1%** | **Philippines—1.1%** |
| Philippines Government International <br> Bond,<br>|  |  |
| 3.700%, due 2/2/42 | 700 | &nbsp;&nbsp; 577 |
| 5.500%, due 2/4/35 | 200 | &nbsp;&nbsp; 212 |
|  |  | &nbsp;&nbsp; 789 |
| **Poland—1.0%** | **Poland—1.0%** | **Poland—1.0%** |
| Poland Government International Bond, |  |  |
| 5.125%, due 9/18/34 | 200 | &nbsp;&nbsp; 204 |
| 5.500%, due 4/4/53 | 350 | &nbsp;&nbsp; 334 |
| 5.500%, due 3/18/54 | 200 | &nbsp;&nbsp; 191 |
|  |  | &nbsp;&nbsp; 729 |
| **Romania—2.3%** | **Romania—2.3%** | **Romania—2.3%** |
| Romania Government International Bond, |  |  |
| 2.000%, due 4/14/33 | 455 | &nbsp;&nbsp; 434 |
| 2.875%, due 4/13/42 | 530 | &nbsp;&nbsp; 410 |
| 5.250%, due 11/25/27 | $400 | &nbsp;&nbsp; 406 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**56**

*Annual*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** |
| **Romania—(continued)** | **Romania—(continued)** | **Romania—(continued)** |
| 5.625%, due 2/22/36<sup>(b)</sup> | 200 | &nbsp;&nbsp; $232 |
| 5.625%, due 5/30/37<sup>(b)</sup> | 150 | &nbsp;&nbsp; 171 |
|  |  | &nbsp;&nbsp; 1653 |
| **Saudi Arabia—0.6%** | **Saudi Arabia—0.6%** | **Saudi Arabia—0.6%** |
| Saudi Arabia Government International <br> Bond, <br>3.450%, due 2/2/61<br>| $650 | &nbsp;&nbsp; 414 |
| **Senegal—0.5%** | **Senegal—0.5%** | **Senegal—0.5%** |
| Senegal Government International Bond, <br>6.750%, due 3/13/48<br>| 700 | &nbsp;&nbsp; 373 |
| **South Africa—1.2%** | **South Africa—1.2%** | **South Africa—1.2%** |
| Republic of South Africa Government <br> International Bond, <br>7.250%, due 12/11/55<sup>(b)</sup><br>| 550 | &nbsp;&nbsp; 545 |
| South Africa Government International <br> Bond, <br>5.750%, due 9/30/49<br>| 350 | &nbsp;&nbsp; 295 |
|  |  | &nbsp;&nbsp; 840 |
| **Sri Lanka—2.1%** | **Sri Lanka—2.1%** | **Sri Lanka—2.1%** |
| Sri Lanka Government International <br> Bond,<br>|  |  |
| 3.350%, due 1/15/30<sup>(a)</sup>,<sup>(b)</sup> | 260 | &nbsp;&nbsp; 246 |
| 3.350%, due 3/15/33<sup>(a)</sup> | 160 | &nbsp;&nbsp; 137 |
| 3.600%, due 6/15/35<sup>(a)</sup> | 200 | &nbsp;&nbsp; 152 |
| 4.000%, due 4/15/28 | 292 | &nbsp;&nbsp; 280 |
| 8.750%, due 3/15/33<sup>(a)</sup>,<sup>(b)</sup> | 300 | &nbsp;&nbsp; 257 |
| 9.500%, due 5/15/36<sup>(a)</sup>,<sup>(b)</sup> | 100 | &nbsp;&nbsp; 91 |
| 9.750%, due 2/15/38<sup>(a)</sup>,<sup>(b)</sup> | 200 | &nbsp;&nbsp; 181 |
| 11.000%, due 12/15/29 | 45000 | &nbsp;&nbsp; 151 |
|  |  | &nbsp;&nbsp; 1495 |
| **Suriname—0.4%** | **Suriname—0.4%** | **Suriname—0.4%** |
| Suriname Government International Bond, <br>8.500%, due 11/6/35<sup>(b)</sup><br>| $300 | &nbsp;&nbsp; 324 |
| **Trinidad and Tobago—1.0%** | **Trinidad and Tobago—1.0%** | **Trinidad and Tobago—1.0%** |
| Trinidad and Tobago Government <br> International Bond,<br>|  |  |
| 6.400%, due 6/26/34<sup>(b)</sup> | 200 | &nbsp;&nbsp; 201 |
| 6.400%, due 6/26/34 | 510 | &nbsp;&nbsp; 514 |
|  |  | &nbsp;&nbsp; 715 |
| **Tunisia—0.5%** | **Tunisia—0.5%** | **Tunisia—0.5%** |
| Tunisian Government Bond, <br>6.375%, due 7/15/26<br>| 320 | &nbsp;&nbsp; 375 |
| **Turkey—2.2%** | **Turkey—2.2%** | **Turkey—2.2%** |
| Turkey Foundation Bank, <br>5 year CMT + 4.439%, 1.000%, due <br> 12/31/99<sup>(b)</sup>,<sup>(d)</sup>,<sup>(e)</sup><br>| $250 | &nbsp;&nbsp; 250 |
| Turkey Government Bond, <br>37.000%, due 2/18/26<br>| 12000 | &nbsp;&nbsp; 279 |
| Turkey Government International Bond, |  |  |
| 4.875%, due 4/16/43 | $200 | &nbsp;&nbsp; 154 |
| 5.250%, due 3/13/30 | 240 | &nbsp;&nbsp; 239 |
| 7.625%, due 5/15/34 | 200 | &nbsp;&nbsp; 217 |
| 9.375%, due 3/14/29 | 400 | &nbsp;&nbsp; 449 |
|  |  | &nbsp;&nbsp; 1588 |

---

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** | **Foreign Government Bonds—(continued)** |
| **Uganda—0.4%** | **Uganda—0.4%** | **Uganda—0.4%** |
| Uganda Government Bond, <br>15.000%, due 6/18/43<br>| 1200000 | &nbsp;&nbsp; $284 |
| **Ukraine—1.5%** | **Ukraine—1.5%** | **Ukraine—1.5%** |
| Ukraine Government International Bond, |  |  |
| 4.000%, due 2/1/32<sup>(a)</sup>,<sup>(b)</sup> | $456 | &nbsp;&nbsp; 344 |
| 7.750%, due 2/1/36<sup>(a)</sup> | 1000 | &nbsp;&nbsp; 585 |
| 7.750%, due 2/1/36<sup>(a)</sup> | 300 | &nbsp;&nbsp; 169 |
|  |  | &nbsp;&nbsp; 1098 |
| **United Arab Emirates—1.1%** | **United Arab Emirates—1.1%** | **United Arab Emirates—1.1%** |
| Abu Dhabi Government International <br> Bond, <br>3.000%, due 9/15/51<br>| 1200 | &nbsp;&nbsp; 815 |
| **Uruguay—1.1%** | **Uruguay—1.1%** | **Uruguay—1.1%** |
| Oriental Republic of Uruguay, <br>5.250%, due 9/10/60<br>| 470 | &nbsp;&nbsp; 440 |
| Uruguay Government International Bond, <br>9.750%, due 7/20/33<br>| 12000 | &nbsp;&nbsp; 345 |
|  |  | &nbsp;&nbsp; 785 |
| **Uzbekistan—0.6%** | **Uzbekistan—0.6%** | **Uzbekistan—0.6%** |
| Uzbekistan Government International <br> Bond,<br>|  |  |
| 5.375%, due 5/29/27<sup>(b)</sup> | 200 | &nbsp;&nbsp; 240 |
| 6.900%, due 2/28/32<sup>(b)</sup> | $200 | &nbsp;&nbsp; 215 |
|  |  | &nbsp;&nbsp; 455 |
| **Venezuela—0.2%** | **Venezuela—0.2%** | **Venezuela—0.2%** |
| Venezuela Government International <br> Bond, <br>11.950%, due 8/5/31<sup>(c)</sup><br>| 400 | &nbsp;&nbsp; 127 |
| **Zambia—1.1%** | **Zambia—1.1%** | **Zambia—1.1%** |
| Zambia Government International Bond, |  |  |
| 0.500%, due 12/31/53 | 400 | &nbsp;&nbsp; 283 |
| 5.750%, due 6/30/33<sup>(a)</sup> | 247 | &nbsp;&nbsp; 243 |
| 21.800%, due 3/17/40 | 5400 | &nbsp;&nbsp; 281 |
|  |  | &nbsp;&nbsp; 807 |
| **Total Foreign Government Bonds** |  | &nbsp;&nbsp; 45657 |
| **Foreign Corporate Bonds—27.3%** | **Foreign Corporate Bonds—27.3%** | **Foreign Corporate Bonds—27.3%** |
| **Angola—0.6%** | **Angola—0.6%** | **Angola—0.6%** |
| Avenir Issuer III (Ireland) Designated <br> Activity Company, <br>6.000%, due 3/22/27<br>| $166 | &nbsp;&nbsp; 162 |
| Avenir Issuer IV (Ireland) Designated <br> Activity Company, <br>6.000%, due 12/30/27<br>| 317 | &nbsp;&nbsp; 308 |
|  |  | &nbsp;&nbsp; 470 |
| **Bahrain—0.4%** | **Bahrain—0.4%** | **Bahrain—0.4%** |
| CBB International Sukuk Programme <br> Company W.L.L., <br>6.250%, due 10/18/30<br>| 250 | &nbsp;&nbsp; 257 |
| **Brazil—1.7%** | **Brazil—1.7%** | **Brazil—1.7%** |
| Aegea Finance S.a r.l., <br>7.625%, due 1/20/36<sup>(b)</sup><br>| 200 | &nbsp;&nbsp; 191 |
| Brazil Minas SPE via State of Minas <br> Gerais, <br>5.333%, due 2/15/28<br>| 207 | &nbsp;&nbsp; 207 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**57**

*William Blair Funds*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** |
| **Brazil—(continued)** | **Brazil—(continued)** | **Brazil—(continued)** |
| CSN Inova Ventures, <br>6.750%, due 1/28/28<br>| $200 | &nbsp;&nbsp; $185 |
| PRIO Luxembourg Holding Sarl, <br>6.750%, due 10/15/30<sup>(b)</sup><br>| 250 | &nbsp;&nbsp; 244 |
| Raizen Fuels Finance SA, <br>6.700%, due 2/25/37<br>| 200 | &nbsp;&nbsp; 162 |
| Yinson Bergenia Production B.V., <br>8.498%, due 1/31/45<sup>(b)</sup><br>| 230 | &nbsp;&nbsp; 241 |
|  |  | &nbsp;&nbsp; 1230 |
| **Chile—1.3%** | **Chile—1.3%** | **Chile—1.3%** |
| Corp. Nacional del Cobre de Chile, |  |  |
| 3.700%, due 1/30/50 | 410 | &nbsp;&nbsp; 291 |
| 6.440%, due 1/26/36<sup>(b)</sup> | 200 | &nbsp;&nbsp; 216 |
| Inversiones CMPC SA, <br>5 year CMT + 2.834%, 6.700%, due <br> 12/9/57<sup>(b)</sup>,<sup>(d)</sup><br>| 250 | &nbsp;&nbsp; 251 |
| Latam Airlines Group S.A., <br>7.875%, due 4/15/30<sup>(b)</sup><br>| 200 | &nbsp;&nbsp; 210 |
|  |  | &nbsp;&nbsp; 968 |
| **China—0.6%** | **China—0.6%** | **China—0.6%** |
| China Oil & Gas Group Limited, <br>4.700%, due 6/30/26<br>| 200 | &nbsp;&nbsp; 197 |
| Prosus N.V., <br>3.061%, due 7/13/31<br>| 250 | &nbsp;&nbsp; 227 |
|  |  | &nbsp;&nbsp; 424 |
| **Colombia—1.6%** | **Colombia—1.6%** | **Colombia—1.6%** |
| Aris Mining Corp, <br>8.000%, due 10/31/29<br>| 250 | &nbsp;&nbsp; 261 |
| Avianca Midco 2 PLC, <br>9.000%, due 12/1/28<br>| 150 | &nbsp;&nbsp; 151 |
| Banco Davivienda S.A., <br>6.650%, due 12/31/99<sup>(e)</sup><br>| 200 | &nbsp;&nbsp; 188 |
| Bancolombia S.A. , <br>5 year CMT + 4.320%, 8.625%, due <br> 12/24/34<sup>(d)</sup><br>| 250 | &nbsp;&nbsp; 267 |
| Bogota Distrito Capital, <br>13.140%, due 11/5/35<sup>(b)</sup><br>| 1060000 | &nbsp;&nbsp; 281 |
|  |  | &nbsp;&nbsp; 1148 |
| **Costa Rica—0.3%** | **Costa Rica—0.3%** | **Costa Rica—0.3%** |
| Liberty Costa Rica Senior Secured <br> Finance, <br>10.875%, due 1/15/31<br>| $200 | &nbsp;&nbsp; 210 |
| **El Salvador—0.2%** | **El Salvador—0.2%** | **El Salvador—0.2%** |
| Comision Ejecutiva Hidroelectrica del <br> Rio Lempa, <br>8.650%, due 1/24/33<sup>(b)</sup><br>| 150 | &nbsp;&nbsp; 161 |
| **Hungary—0.3%** | **Hungary—0.3%** | **Hungary—0.3%** |
| OTP Bank Nyrt., <br>5 year CMT + 2.861%, 7.300%, due <br> 7/30/35<sup>(d)</sup><br>| 200 | &nbsp;&nbsp; 210 |
| **India—1.5%** | **India—1.5%** | **India—1.5%** |
| Inter-American Development Bank, <br>7.350%, due 10/6/30<br>| 22000 | &nbsp;&nbsp; 249 |
| IRB Infrastructure Developers Limited, <br>7.110%, due 3/11/32<br>| $250 | &nbsp;&nbsp; 258 |

---

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** |
| **India—(continued)** | **India—(continued)** | **India—(continued)** |
| Network i2i Limited, <br>5 year CMT + 3.390%, 3.975%, due <br> 12/31/99<sup>(d)</sup>,<sup>(e)</sup><br>| $200 | &nbsp;&nbsp; $199 |
| Sael Limited, <br>7.800%, due 7/31/31<br>| 188 | &nbsp;&nbsp; 192 |
| Vedanta Resources, <br>9.850%, due 4/24/33<br>| 200 | &nbsp;&nbsp; 206 |
|  |  | &nbsp;&nbsp; 1104 |
| **Indonesia—2.4%** | **Indonesia—2.4%** | **Indonesia—2.4%** |
| Indonesia Government Sukuk, <br>5.200%, due 7/23/35<sup>(b)</sup><br>| 250 | &nbsp;&nbsp; 255 |
| Nickel Industries Limited, <br>9.000%, due 9/30/30<sup>(b)</sup><br>| 250 | &nbsp;&nbsp; 259 |
| Pertamina Persero PT, <br>2.300%, due 2/9/31<br>| 450 | &nbsp;&nbsp; 400 |
| PT Bank Negara Indonesia (Persero) Tbk, <br>3.750%, due 3/30/26<br>| 200 | &nbsp;&nbsp; 198 |
| PT Pertamina (Persero), <br>6.000%, due 5/3/42<br>| 200 | &nbsp;&nbsp; 203 |
| PT Pertamina Hulu Energi, <br>5.250%, due 5/21/30<sup>(b)</sup><br>| 250 | &nbsp;&nbsp; 255 |
| PT Sorik Marapi Geothermal Power, <br>7.750%, due 8/5/31<sup>(b)</sup><br>| 192 | &nbsp;&nbsp; 197 |
|  |  | &nbsp;&nbsp; 1767 |
| **Iraq—0.3%** | **Iraq—0.3%** | **Iraq—0.3%** |
| Pearl Petroleum, <br>13.000%, due 5/15/28<br>| 200 | &nbsp;&nbsp; 217 |
| **Kazakhstan—0.6%** | **Kazakhstan—0.6%** | **Kazakhstan—0.6%** |
| ForteBank JSC, <br>7.750%, due 2/4/30<br>| 250 | &nbsp;&nbsp; 251 |
| JSC Kaspi.kz, <br>6.250%, due 3/26/30<sup>(b)</sup><br>| 200 | &nbsp;&nbsp; 204 |
|  |  | &nbsp;&nbsp; 455 |
| **Macao—0.3%** | **Macao—0.3%** | **Macao—0.3%** |
| Melco Resorts & Entertainment Limited, <br>5.375%, due 12/4/29<br>| 250 | &nbsp;&nbsp; 247 |
| **Malaysia—0.9%** | **Malaysia—0.9%** | **Malaysia—0.9%** |
| Khazanah Capital Limited, |  |  |
| 4.759%, due 9/5/34 | 450 | &nbsp;&nbsp; 455 |
| 4.876%, due 6/1/33 | 200 | &nbsp;&nbsp; 204 |
|  |  | &nbsp;&nbsp; 659 |
| **Mexico—3.6%** | **Mexico—3.6%** | **Mexico—3.6%** |
| America Movil SAB de CV, <br>10.300%, due 1/30/34<br>| 4300 | &nbsp;&nbsp; 249 |
| Banco Mercantil del Norte, <br>5 year CMT + 4.072%, 8.375%, due <br> 12/31/99<sup>(d)</sup>,<sup>(e)</sup><br>| $200 | &nbsp;&nbsp; 209 |
| Eagle Funding LuxCo S.a r.l., <br>5.500%, due 8/17/30<sup>(b)</sup><br>| 500 | &nbsp;&nbsp; 509 |
| Petroleos Mexicanos, |  |  |
| 6.750%, due 9/21/47 | 1175 | &nbsp;&nbsp; 964 |
| 6.840%, due 1/23/30 | 310 | &nbsp;&nbsp; 315 |
| 7.690%, due 1/23/50 | 220 | &nbsp;&nbsp; 197 |
| Saavi Energia S.a r.l., <br>8.875%, due 2/10/35<sup>(b)</sup><br>| 200 | &nbsp;&nbsp; 216 |
|  |  | &nbsp;&nbsp; 2659 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**58**

*Annual*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** |
| **Peru—1.5%** | **Peru—1.5%** | **Peru—1.5%** |
| Banco de Credito del Peru S.A., |  |  |
| 7.850%, due 1/11/29<sup>(b)</sup> | 400 | &nbsp;&nbsp; $126 |
| 7.850%, due 1/11/29 | 250 | &nbsp;&nbsp; 79 |
| Compania de Minas Buenaventura <br> S.A.A., <br>6.800%, due 2/4/32<sup>(b)</sup><br>| $200 | &nbsp;&nbsp; 208 |
| Credicorp Capital Sociedad Titulizadora <br> S.A., <br>9.700%, due 3/5/45<br>| 480 | &nbsp;&nbsp; 150 |
| Minsur SA, <br>4.500%, due 10/28/31<br>| $300 | &nbsp;&nbsp; 287 |
| Volcan Cia Minera SAA, <br>8.500%, due 10/28/32<sup>(b)</sup><br>| 250 | &nbsp;&nbsp; 256 |
|  |  | &nbsp;&nbsp; 1106 |
| **Saudi Arabia—2.4%** | **Saudi Arabia—2.4%** | **Saudi Arabia—2.4%** |
| Dar Al-Arkan Sukuk Company Limited, <br>7.250%, due 7/2/30<br>| 250 | &nbsp;&nbsp; 253 |
| Gaci First Investment Co., <br>4.875%, due 2/14/35<br>| 400 | &nbsp;&nbsp; 397 |
| KSA Sukuk Limited, <br>5.250%, due 6/4/34<br>| 800 | &nbsp;&nbsp; 825 |
| SAB AT1 Limited, <br>5 year CMT + 2.302%, 6.500%, due <br> 12/31/99<sup>(d)</sup>,<sup>(e)</sup><br>| 250 | &nbsp;&nbsp; 254 |
|  |  | &nbsp;&nbsp; 1729 |
| **Serbia—0.3%** | **Serbia—0.3%** | **Serbia—0.3%** |
| Telekom Srbija, <br>7.000%, due 10/28/29<br>| 200 | &nbsp;&nbsp; 200 |
| **South Africa—0.3%** | **South Africa—0.3%** | **South Africa—0.3%** |
| Stillwater Mining Co., <br>4.000%, due 11/16/26<br>| 210 | &nbsp;&nbsp; 208 |
| **Supranational—0.3%** | **Supranational—0.3%** | **Supranational—0.3%** |
| Africa Finance Corporation, <br>5 year CMT + 3.015%, 7.500%, due <br> 12/31/99<sup>(b)</sup>,<sup>(d)</sup>,<sup>(e)</sup><br>| 200 | &nbsp;&nbsp; 202 |
| **Trinidad and Tobago—0.6%** | **Trinidad and Tobago—0.6%** | **Trinidad and Tobago—0.6%** |
| Heritage Petroleum Company, <br>9.000%, due 8/12/29<br>| 200 | &nbsp;&nbsp; 206 |
| Port of Spain Waterfront Development, <br>7.875%, due 2/19/40<sup>(b)</sup><br>| 193 | &nbsp;&nbsp; 192 |
|  |  | &nbsp;&nbsp; 398 |
| **Turkey—0.6%** | **Turkey—0.6%** | **Turkey—0.6%** |
| Cimko Cement and Concrete Industry and <br> Trade Inc., <br>10.750%, due 5/21/30<br>| 200 | &nbsp;&nbsp; 212 |
| Export Credit Bank of Turkey, <br>5.750%, due 7/6/26<br>| 200 | &nbsp;&nbsp; 201 |
|  |  | &nbsp;&nbsp; 413 |
| **United Arab Emirates—2.5%** | **United Arab Emirates—2.5%** | **United Arab Emirates—2.5%** |
| Abu Dhabi Commercial Bank, <br>5 year CMT + 1.677%, 5.361%, due <br> 3/10/35<sup>(d)</sup><br>| 250 | &nbsp;&nbsp; 254 |

---

---

| | | | |
|:---|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Principal**<br> **Amount** | **Value** |
| **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** | **Foreign Corporate Bonds—(continued)** |
| **United Arab Emirates—(continued)** | **United Arab Emirates—(continued)** | **United Arab Emirates—(continued)** | **United Arab Emirates—(continued)** |
| Abu Dhabi Developmental Holding <br> Company PJSC, <br>5.375%, due 5/8/29<br>| $| 200 | &nbsp;&nbsp; $207 |
| Aldar Properties PJSC, <br>5 year CMT + 2.042%, 6.623%, due <br> 4/15/55<sup>(d)</sup><br>|  | 200 | &nbsp;&nbsp; 209 |
| Finance Department Government of <br> Sharjah,<br>|  |  |  |
| 4.000%, due 7/28/50 |  | 700 | &nbsp;&nbsp; 469 |
| 6.125%, due 3/6/36<sup>(b)</sup> |  | 200 | &nbsp;&nbsp; 206 |
| First Abu Dhabi Bank PJSC, <br>6 year CMT + 4.138%, 4.500%, due <br> 12/31/99<sup>(d)</sup>,<sup>(e)</sup><br>|  | 250 | &nbsp;&nbsp; 249 |
| Sobha Sukuk Limited, <br>8.750%, due 7/17/28<br>|  | 250 | &nbsp;&nbsp; 260 |
|  |  |  | &nbsp;&nbsp; 1854 |
| **Uruguay—0.3%** | **Uruguay—0.3%** | **Uruguay—0.3%** | **Uruguay—0.3%** |
| Navios South American Logistics Inc, <br>8.875%, due 7/14/30<br>|  | 200 | &nbsp;&nbsp; 206 |
| **Uzbekistan—0.6%** | **Uzbekistan—0.6%** | **Uzbekistan—0.6%** | **Uzbekistan—0.6%** |
| Ipoteka-Bank ATIB, <br>6.450%, due 10/9/30<br>|  | 250 | &nbsp;&nbsp; 250 |
| Uzauto Motors AJ, <br>7.375%, due 11/19/30<sup>(b)</sup><br>|  | 200 | &nbsp;&nbsp; 200 |
|  |  |  | &nbsp;&nbsp; 450 |
| **Venezuela—1.3%** | **Venezuela—1.3%** | **Venezuela—1.3%** | **Venezuela—1.3%** |
| Petroleum of Venezuela S.A., |  |  |  |
| 8.500%, due 10/27/20<sup>(c)</sup> |  | 75 | &nbsp;&nbsp; 75 |
| 12.750%, due 2/17/22<sup>(c)</sup> |  | 3140 | &nbsp;&nbsp; 892 |
|  |  |  | &nbsp;&nbsp; 967 |
| **Total Foreign Corporate Bonds** |  |  | &nbsp;&nbsp; 19919 |
| **Foreign Municipal Bonds—0.3%** | **Foreign Municipal Bonds—0.3%** | **Foreign Municipal Bonds—0.3%** | **Foreign Municipal Bonds—0.3%** |
| **Argentina—0.3%** | **Argentina—0.3%** | **Argentina—0.3%** | **Argentina—0.3%** |
| Provincia de Buenos Aires, |  |  |  |
| 5.875%, due 9/1/37<sup>(a)</sup>,<sup>(b)</sup> |  | 50 | &nbsp;&nbsp; 33 |
| 6.625%, due 9/1/37<sup>(a)</sup> |  | 285 | &nbsp;&nbsp; 218 |
|  |  |  | &nbsp;&nbsp; 251 |
| **Total Foreign Municipal Bonds** |  |  | &nbsp;&nbsp; 251 |
| **U.S. Government—3.3%** | **U.S. Government—3.3%** | **U.S. Government—3.3%** | **U.S. Government—3.3%** |
| U.S. Treasury Bill, |  |  |  |
| 3.448%, due 7/9/26<sup>(f)</sup> |  | 980 | &nbsp;&nbsp; 963 |
| 3.485%, due 10/1/26 |  | 360 | &nbsp;&nbsp; 351 |
| 3.502%, due 10/29/26 |  | 180 | &nbsp;&nbsp; 175 |
| 3.532%, due 6/11/26 |  | 500 | &nbsp;&nbsp; 492 |
| U.S. Treasury Bond, <br>4.860%, due 8/15/54<br>|  | 480 | &nbsp;&nbsp; 434 |
| **Total U.S. Government** |  |  | &nbsp;&nbsp; 2415 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**59**

*William Blair Funds*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | |
|:---|:---|:---|
| **Issuer** | **Principal**<br> **Amount** | **Value** |
| **Repurchase Agreements—3.1%** | **Repurchase Agreements—3.1%** | **Repurchase Agreements—3.1%** |
| Fixed Income Clearing Corporation, <br> 1.150% dated 12/31/25, due 01/02/26, <br> repurchase price $2,264, collateralized <br> by U.S. Treasury Bond, 4.750%, due <br> 02/15/2041, valued at $2,309<br>| $2264 | &nbsp;&nbsp; $2264 |
| **Total Repurchase Agreements—3.1%** <br>(cost $2,264)<br>|  | &nbsp;&nbsp; 2264 |
| **Total Purchased Options—0.1%** <br>(premiums paid $97)<br>|  | &nbsp;&nbsp; 74 |
| **Total Investments—96.7%** <br>(cost $66,231)<br>|  | &nbsp;&nbsp; 70580 |
| **Cash and other assets, less** <br> **liabilities—3.3%**<br>|  | &nbsp;&nbsp; 2418 |
| **Net Assets—100.0%** |  | &nbsp;&nbsp; $72998 |

---

------

CMT Constant Maturity Treasury <br> PLC Public Limited Company

&nbsp;&nbsp;&nbsp;&nbsp;(a) Variable/Floating interest rate security. Certain variable/floating interest rate securities are not based on a published reference rate and spread but are determined by the issuer or agent and are based on current market conditions. These securities do not indicate a reference rate and spread in their description above. Rate presented is as of December 31, 2025.

&nbsp;&nbsp;&nbsp;&nbsp;(b) Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may only be resold in transactions exempt from registration, normally to qualified institutional buyers.

&nbsp;&nbsp;&nbsp;&nbsp;(c) Security is currently in default and/or non-income producing.

&nbsp;&nbsp;&nbsp;&nbsp;(d) Floating Rate Bond. Rate shown is as of December 31, 2025.

&nbsp;&nbsp;&nbsp;&nbsp;(e) Security is perpetual in nature and has no stated maturity.

&nbsp;&nbsp;&nbsp;&nbsp;(f) Security, or portion of security, is segregated as collateral to cover initial margin requirements on centrally cleared swaps aggregating a total value of $455 (in thousands).

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **Forward Foreign Currency Contracts** | **Forward Foreign Currency Contracts** | **Forward Foreign Currency Contracts** | **Forward Foreign Currency Contracts** | **Forward Foreign Currency Contracts** | **Forward Foreign Currency Contracts** | **Forward Foreign Currency Contracts** |
| **Settlement** <br>**Date**<br>| **Deliver/Receive** | **Counterparty** | **Local Currency** <br>**(in thousands)**<br>| **USD (Base)** <br>**Purchased** <br>**or Sold**<br>| **Current** <br>**Value**<br>| **Net** <br>**Unrealized** <br>**Appreciation** <br>**(Depreciation)**<br>|
| *Foreign Currency Bought* |  |  |  |  |  |  |
| 1/16/26 | Argentine Peso | Citibank N.A. | 474740 | $334 | $322 | &nbsp;&nbsp;&nbsp;&nbsp; $(12)<br>|
| 3/18/26 | Indian Rupee | Citibank N.A. | 14843 | 164 | 164 | &nbsp;&nbsp;&nbsp;&nbsp; — |
| 3/18/26 | Uzbekistan Sum | Citibank N.A. | 3899258 | 321 | 319 | &nbsp;&nbsp;&nbsp;&nbsp; (2)<br>|
| 3/18/26 | Angola Kwanza | Citibank N.A. | 158818 | 170 | 169 | &nbsp;&nbsp;&nbsp;&nbsp; (1)<br>|
| 3/18/26 | Ukranian Hryvnia | Citibank N.A. | 7151 | 166 | 166 | &nbsp;&nbsp;&nbsp;&nbsp; — |
| 3/18/26 | Kenyan Shilling | Citibank N.A. | 22286 | 170 | 171 | &nbsp;&nbsp;&nbsp;&nbsp; 1 |
| *Foreign Currency Sold* |  |  |  |  |  |  |
| 1/16/26 | Argentine Peso | Citibank N.A. | 624740 | 428 | 424 | &nbsp;&nbsp;&nbsp;&nbsp; 4 |
| 3/18/26 | Colombian Peso | Citibank N.A. | 2578075 | 657 | 666 | &nbsp;&nbsp;&nbsp;&nbsp; (9)<br>|
| 3/18/26 | Euro | Citibank N.A. | 3339 | 3905 | 3937 | &nbsp;&nbsp;&nbsp;&nbsp; (32)<br>|
| **Total net unrealized appreciation (depreciation) on forward foreign currency contracts** | **Total net unrealized appreciation (depreciation) on forward foreign currency contracts** | **Total net unrealized appreciation (depreciation) on forward foreign currency contracts** | **Total net unrealized appreciation (depreciation) on forward foreign currency contracts** | **Total net unrealized appreciation (depreciation) on forward foreign currency contracts** | **Total net unrealized appreciation (depreciation) on forward foreign currency contracts** | &nbsp;&nbsp;&nbsp;&nbsp; $(51)<br>|

---

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  | **Purchased Options Contracts**  |
| **Description** | **Counterparty** | **Exercise** <br>**Price/Rate**<br>| **Expiration** <br>**Date**<br>| **Number of** <br>**Contracts**<br>| **Notional** <br>**Amount** <br>**(in thousands)** | **Notional** <br>**Amount** <br>**(in thousands)** | **Value** | **Premiums** <br>**Paid**<br>| **Unrealized** <br>**Appreciation/** <br>**(Depreciation)**<br>|
| Call–OTC EUR <br> versus USD<br>| Citibank N.A. | 1.1972 | &nbsp;&nbsp; 6/15/2026 | &nbsp;&nbsp; 1228000 | &nbsp;&nbsp; EUR | &nbsp;&nbsp; 1228 | &nbsp;&nbsp; $16 | &nbsp;&nbsp; $19 | &nbsp;&nbsp; $(3)<br>|
| Call–OTC EUR <br> versus USD<br>| Citibank N.A. | 1.1987 | &nbsp;&nbsp; 6/15/2026 | &nbsp;&nbsp; 1666000 |  | &nbsp;&nbsp; 1666 | &nbsp;&nbsp; 21 | &nbsp;&nbsp; 25 | &nbsp;&nbsp; (4)<br>|

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**60**

*Annual*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** | **Purchased Options Contracts (continued)** |
| **Description** | **Counterparty** | **Exercise**<br> **Price/Rate**<br>| **Expiration**<br> **Date**<br>| **Number of**<br> **Contracts**<br>| **Notional**<br> **Amount**<br> **(in thousands)** | **Value** | **Premiums**<br> **Paid**<br>| **Unrealized**<br> **Appreciation/**<br> **(Depreciation)**<br>|
| Put–OTC EUR <br> versus USD<br>| Citibank N.A. | 1.1749 | &nbsp;&nbsp; 6/15/2026 | &nbsp;&nbsp; 1666000 | &nbsp;&nbsp; 1666 | &nbsp;&nbsp; $23 | &nbsp;&nbsp; $25 | &nbsp;&nbsp; $(2)<br>|
| Put–OTC USD <br> versus JPY<br>| Citibank N.A. | 155.0200 | &nbsp;&nbsp; 2/24/2026 | &nbsp;&nbsp; 1371300 | $&nbsp;&nbsp; 1371 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; 28 | &nbsp;&nbsp; (14)<br>|
|  |  |  |  |  |  | &nbsp;&nbsp; $74 | &nbsp;&nbsp; $97 | &nbsp;&nbsp; $(23)<br>|

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  | **Centrally Cleared Credit Default Swaps**  |
| **Reference** <br>**Entity**<br>| **Buy/Sell** <br>**Protection**<br>| **Fixed (Pay)** <br>**Receive Rate**<br>| **Payment** <br>**Frequency**<br>| **Maturity** <br>**Date**<br>| **Notional** <br>**Amount** <br>**(in thousands)** | **Upfront** <br>**Payment** <br>**Paid** <br>**(Received)**<br>| **Value** | **Unrealized** <br>**Appreciation** <br>**(Depreciation)**<br>|
| Argentine Republic <br> Government <br> International <br> Bond<br>| Buy | (1.000)% | Quarterly | June 2027<br> ICE | $250 | $205 | $15 | $(190)<br>|
| Argentine Republic <br> Government <br> International <br> Bond<br>| Buy | (1.000)% | Quarterly | December 2029<br> ICE | 204 | 94 | 36 | (58)<br>|
| Ivory Coast <br> Government <br> International <br> Bond<br>| Buy | (1.000)% | Quarterly | December 2030<br> ICE | 300 | 23 | 20 | (3)<br>|
| Republic of South <br> Africa <br> Government <br> International <br> Bond<br>| Buy | (1.000)% | Quarterly | December 2030<br> ICE | 300 | 5 | 4 | (1)<br>|
| Saudi Arabia <br> Government <br> International <br> Bond<br>| Buy | (1.000)% | Quarterly | December 2026<br> ICE | 400 | (6)<br>| (3)<br>| 3 |
| Turkey Government <br> International <br> Bond<br>| Buy | (1.000)% | Quarterly | December 2030<br> ICE | 750 | 54 | 34 | (20)<br>|
| Argentine Republic <br> Government <br> International <br> Bond<br>| Sell | 5.000% | Quarterly | June 2027<br> ICE | 250 | (190)<br>| (1)<br>| 189 |
|  |  |  |  |  |  |  |  | $(80)<br>|

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  | **Centrally Cleared Interest Rate Swaps**  |
| **Floating Rate** <br>**Reference**<br>| **Pay/Receive** <br>**Floating Rate**<br>| **Fixed** <br>**Rate**<br>| **Payment** <br>**Frequency**<br>| **Maturity** <br>**Date**<br>| **Notional** <br>**Amount** <br>**(in thousands)** | **Upfront** <br>**Payment** <br>**Paid** <br>**(Received)**<br>| **Value** | **Unrealized** <br>**Appreciation** <br>**(Depreciation)**<br>|
| 1-Day USD-SOFR <br> Compounded<br>| Pay | 4.500% | Annual | March 2027<br> LCH | $4835 | $45 | $74 | $29 |
| 1-Day USD-SOFR <br> Compounded<br>| Pay | 4.250% | Annual | March 2029<br> LCH | 3614 | 24 | 99 | 75 |
| 1-Day USD-SOFR <br> Compounded<br>| Pay | 3.750% | Annual | March 2032<br> LCH | 3873 | 1 | 28 | 27 |
| 1-Day USD-SOFR <br> Compounded<br>| Pay | 3.600% | Annual | September 2035<br> LCH | 2621 | 1 | (43)<br>| (44)<br>|
| 1-Day USD-SOFR <br> Compounded<br>| Pay | 4.000% | Annual | March 2044<br> LCH | 4275 | (20)<br>| (87)<br>| (67)<br>|
| 1-Day USD-SOFR <br> Compounded<br>| Receive | 3.500% | Annual | September 2054<br> LCH | 3092 | 194 | 357 | 163 |
| 6-Month EUR-<br> EURIBOR<br>| Receive | 3.000% | Annual | March 2027<br> LCH | 170 |  | (6)<br>| (6)<br>|
| 6-Month EUR-<br> EURIBOR<br>| Receive | 2.750% | Annual | March 2031<br> LCH | 689 | (23)<br>| (19)<br>| 4 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**61**

*William Blair Funds*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** | **Centrally Cleared Interest Rate Swaps (continued)** |
| **Floating Rate**<br> **Reference**<br>| **Pay/Receive**<br> **Floating Rate**<br>| **Fixed**<br> **Rate**<br>| **Payment**<br> **Frequency**<br>| **Maturity**<br> **Date**<br>| **Notional**<br> **Amount**<br> **(in thousands)** | **Notional**<br> **Amount**<br> **(in thousands)** | **Upfront**<br> **Payment**<br> **Paid**<br> **(Received)**<br>| **Value** | **Unrealized**<br> **Appreciation**<br> **(Depreciation)**<br>|
| 6-Month EUR-<br> EURIBOR<br>| Receive | 3.250% | Annual | September 2033<br> LCH | EUR | 400 | (25)<br>| (17)<br>| 8 |
| 6-Month EUR-<br> EURIBOR<br>| Receive | 2.750% | Annual | March 2034<br> LCH |  | 172 | (4)<br>| (2)<br>| 2 |
| 6-Month EUR-<br> EURIBOR<br>| Receive | 3.250% | Annual | September 2037<br> LCH |  | 494 | (25)<br>| (15)<br>| 10 |
| 6-Month EUR-<br> EURIBOR<br>| Receive | 2.750% | Annual | March 2039<br> LCH |  | 1222 | (8)<br>| 32 | 40 |
| 6-Month EUR-<br> EURIBOR<br>| Receive | 2.500% | Annual | March 2049<br> LCH |  | 182 | 13 | 24 | 11 |
|  |  |  |  |  |  |  |  |  | $252 |
| **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | **Total net unrealized appreciation (depreciation) on swaps** | $172 |

---

------

---

| | |
|:---|:---|
| ICE | Intercontinental Exchange |
| SOFR | Secured Overnight Financing Rate |
| LCH | London Clearing House |
| EURIBOR | Euro Interbank Offered Rate |

---

---

| | |
|:---|:---|
| **Currency Legend** | **Currency Legend** |
| ARS | Argentina Peso |
| BRL | Brazilian Real |
| CLP | Chile Peso |
| COP | Colombian Peso |
| DOP | Dominican Republic Peso |
| EGP | Egyptian Pound |
| EUR | Euro |
| HUF | Hungary Forint |
| INR | Indian Rupee |
| JMD | Jamaican Dollar |
| KZT | Kazakhstan Tenge |
| LKR | Sri Lanka Rupee |
| MXN | Mexican Peso |
| NGN | Nigerian Naira |
| PEN | Peruvian Nuevo Sol |
| PKR | Pakistani Rupee |
| PYG | Paraguay Guarani |
| TRY | Turkish Lira |
| UGX | Uganda Shilling |
| USD | United States Dollar |
| UYU | Uruguayan Peso |
| ZMW | Zambian Kwacha |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**62**

*Annual*

------

**Emerging Markets Debt Fund**

**Portfolio of Investments, December 31, 2025** *(all dollar amounts in thousands)*

As of December 31, 2025, the value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown below (in thousands).

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Investments in securities** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Foreign Government Bonds | $— | &nbsp;&nbsp; $45657 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $45657 |
| Foreign Corporate Bonds |  | &nbsp;&nbsp; 19919 | &nbsp;&nbsp; — | &nbsp;&nbsp; 19919 |
| U.S. Government |  | &nbsp;&nbsp; 2415 | &nbsp;&nbsp; — | &nbsp;&nbsp; 2415 |
| Repurchase Agreements |  | &nbsp;&nbsp; 2264 | &nbsp;&nbsp; — | &nbsp;&nbsp; 2264 |
| Foreign Municipal Bonds |  | &nbsp;&nbsp; 251 | &nbsp;&nbsp; — | &nbsp;&nbsp; 251 |
| Purchased Options |  | &nbsp;&nbsp; 74 | &nbsp;&nbsp; — | &nbsp;&nbsp; 74 |
| **Total Investments in Securities** | $— | &nbsp;&nbsp; $70580 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $70580 |

---

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Other Financial Instruments** | **Level 1** | **Level 2** | **Level 3** | **Total** |
| **Assets** |  |  |  |  |
| Forward Foreign Currency Contracts | $— | &nbsp;&nbsp; $5 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $5 |
| Swaps |  | &nbsp;&nbsp; 561 | &nbsp;&nbsp; — | &nbsp;&nbsp; 561 |
| **Liabilities** |  |  |  |  |
| Forward Foreign Currency Contracts |  | &nbsp;&nbsp; (56)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (56)<br>|
| Swaps |  | &nbsp;&nbsp; (389)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (389)<br>|
| **Total Other Financial Instruments** | $— | &nbsp;&nbsp; $121 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $121 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**63**

*William Blair Funds*

------

**Statements of Assets and Liabilities**

**As of December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Growth** <br>**Fund**<br>| **Large Cap** <br>**Growth** <br>**Fund**<br>| **Mid Cap** <br>**Value** <br>**Fund**<br>| **Small-Mid** <br>**Cap Core** <br>**Fund**<br>|
| ***Assets*** |  |  |  |  |
| Investments in securities, at cost | $162463 | &nbsp;&nbsp; $1850430 | &nbsp;&nbsp; $1060 | &nbsp;&nbsp; $111381 |
| Investments in securities, at value | $228421 | &nbsp;&nbsp; $2630794 | &nbsp;&nbsp; $1310 | &nbsp;&nbsp; $122968 |
| Cash |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 77 | &nbsp;&nbsp; — |
| Receivable for securities sold | 176 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Receivable for fund shares sold | 3 | &nbsp;&nbsp; 1790 | &nbsp;&nbsp; — | &nbsp;&nbsp; 24835 |
| Receivable from Adviser | 2 | &nbsp;&nbsp; 228 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; 15 |
| Dividends and interest receivable | 34 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 71 |
| Total assets | 228636 | &nbsp;&nbsp; 2632813 | &nbsp;&nbsp; 1404 | &nbsp;&nbsp; 147889 |
| ***Liabilities*** |  |  |  |  |
| Payable for fund shares redeemed | 41 | &nbsp;&nbsp; 1194 | &nbsp;&nbsp; — | &nbsp;&nbsp; 24589 |
| Management fee payable | 151 | &nbsp;&nbsp; 1361 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 96 |
| Distribution fee payable | 6 | &nbsp;&nbsp; 29 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Other payables and accrued expenses | 73 | &nbsp;&nbsp; 500 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 75 |
| Total liabilities | 271 | &nbsp;&nbsp; 3084 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; 24760 |
| Net assets | $228365 | &nbsp;&nbsp; $2629729 | &nbsp;&nbsp; $1353 | &nbsp;&nbsp; $123129 |
| ***Capital*** |  |  |  |  |
| Composition of net assets |  |  |  |  |
| Paid in capital | $157087 | &nbsp;&nbsp; $1822802 | &nbsp;&nbsp; $1108 | &nbsp;&nbsp; $111790 |
| Total distributable earnings (loss) | 71278 | &nbsp;&nbsp; 806927 | &nbsp;&nbsp; 245 | &nbsp;&nbsp; 11339 |
| Net assets | $228365 | &nbsp;&nbsp; $2629729 | &nbsp;&nbsp; $1353 | &nbsp;&nbsp; $123129 |
| Class N shares |  |  |  |  |
| Net assets | $28449 | &nbsp;&nbsp; $132535 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Shares outstanding | 4243138 | &nbsp;&nbsp; 4799832 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net asset value per share | $6.70 | &nbsp;&nbsp; $27.61 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I shares |  |  |  |  |
| Net assets | $162350 | &nbsp;&nbsp; $1905753 | &nbsp;&nbsp; $70 | &nbsp;&nbsp; $18138 |
| Shares outstanding | 14862067 | &nbsp;&nbsp; 63252485 | &nbsp;&nbsp; 5853 | &nbsp;&nbsp; 1090575 |
| Net asset value per share | $10.92 | &nbsp;&nbsp; $30.13 | &nbsp;&nbsp; $11.86 | &nbsp;&nbsp; $16.63 |
| Class R6 shares |  |  |  |  |
| Net assets | $37566 | &nbsp;&nbsp; $591441 | &nbsp;&nbsp; $1283 | &nbsp;&nbsp; $104991 |
| Shares outstanding | 3409017 | &nbsp;&nbsp; 19624665 | &nbsp;&nbsp; 108217 | &nbsp;&nbsp; 6306323 |
| Net asset value per share | $11.02 | &nbsp;&nbsp; $30.14 | &nbsp;&nbsp; $11.86 | &nbsp;&nbsp; $16.65 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**64**

*Annual*

------

**Statements of Operations**

**For the Year Ended December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Growth** <br>**Fund**<br>| **Large Cap** <br>**Growth** <br>**Fund**<br>| **Mid Cap** <br>**Value** <br>**Fund**<br>| **Small-Mid** <br>**Cap Core** <br>**Fund**<br>|
| ***Investment income*** |  |  |  |  |
| Dividends | $1055 | &nbsp;&nbsp; $12394 | &nbsp;&nbsp; $29 | &nbsp;&nbsp; $1337 |
| Less foreign tax withheld | (3)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (11)<br>|
| Interest | 49 | &nbsp;&nbsp; 161 | &nbsp;&nbsp; — | &nbsp;&nbsp; 44 |
| Total income | 1101 | &nbsp;&nbsp; 12555 | &nbsp;&nbsp; 29 | &nbsp;&nbsp; 1370 |
| ***Expenses*** |  |  |  |  |
| Management fees | 1763 | &nbsp;&nbsp; 16282 | &nbsp;&nbsp; 11 | &nbsp;&nbsp; 1146 |
| Distribution fees | 74 | &nbsp;&nbsp; 379 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Custodian fees | 60 | &nbsp;&nbsp; 85 | &nbsp;&nbsp; 57 | &nbsp;&nbsp; 70 |
| Transfer agent fees | 84 | &nbsp;&nbsp; 181 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 10 |
| Sub-transfer agent fees |  |  |  |  |
| Class N | 38 | &nbsp;&nbsp; 197 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I | 66 | &nbsp;&nbsp; 2129 | &nbsp;&nbsp; — | &nbsp;&nbsp; 77 |
| Professional fees | 48 | &nbsp;&nbsp; 243 | &nbsp;&nbsp; 31 | &nbsp;&nbsp; 38 |
| Registration fees | 48 | &nbsp;&nbsp; 77 | &nbsp;&nbsp; 35 | &nbsp;&nbsp; 35 |
| Shareholder reporting fees | 19 | &nbsp;&nbsp; 93 | &nbsp;&nbsp; 9 | &nbsp;&nbsp; 11 |
| Trustee fees | 22 | &nbsp;&nbsp; 254 | &nbsp;&nbsp; — | &nbsp;&nbsp; 12 |
| Other expenses | 12 | &nbsp;&nbsp; 87 | &nbsp;&nbsp; 4 | &nbsp;&nbsp; 8 |
| Total expenses before expense limitation | 2234 | &nbsp;&nbsp; 20007 | &nbsp;&nbsp; 148 | &nbsp;&nbsp; 1407 |
| Expenses waived or reimbursed by the Adviser |  |  |  |  |
| Class N | (15)<br>| &nbsp;&nbsp; (178)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I |  | &nbsp;&nbsp; (1888)<br>| &nbsp;&nbsp; (7)<br>| &nbsp;&nbsp; (127)<br>|
| Class R6 |  | &nbsp;&nbsp; (231)<br>| &nbsp;&nbsp; (130)<br>| &nbsp;&nbsp; (108)<br>|
| Total expenses waived or reimbursed by the Adviser | (15)<br>| &nbsp;&nbsp; (2297)<br>| &nbsp;&nbsp; (137)<br>| &nbsp;&nbsp; (235)<br>|
| Net expenses | 2219 | &nbsp;&nbsp; 17710 | &nbsp;&nbsp; 11 | &nbsp;&nbsp; 1172 |
| Net investment income (loss) | (1118)<br>| &nbsp;&nbsp; (5155)<br>| &nbsp;&nbsp; 18 | &nbsp;&nbsp; 198 |
| ***Realized and unrealized gain (loss)*** |  |  |  |  |
| Net realized gain (loss) on transactions from: |  |  |  |  |
| Investments in securities | 56339 | &nbsp;&nbsp; 207500 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; 1181 |
| Total net realized gain | 56339 | &nbsp;&nbsp; 207500 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; 1181 |
| Change in net unrealized appreciation (depreciation) of: |  |  |  |  |
| Investments in securities | (32212)<br>| &nbsp;&nbsp; 96681 | &nbsp;&nbsp; 76 | &nbsp;&nbsp; 802 |
| Change in net unrealized appreciation (depreciation) | (32212)<br>| &nbsp;&nbsp; 96681 | &nbsp;&nbsp; 76 | &nbsp;&nbsp; 802 |
| **Net increase (decrease) in net assets resulting from operations** | $23009 | &nbsp;&nbsp; $299026 | &nbsp;&nbsp; $108 | &nbsp;&nbsp; $2181 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**65**

*William Blair Funds*

------

**Statements of Changes in Net Assets**

**For the Years Ended December 31, 2025 and 2024** *(dollar amounts in thousands)*

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Growth** <br>**Fund** | **Growth** <br>**Fund** | **Large Cap** <br>**Growth** <br>**Fund** | **Large Cap** <br>**Growth** <br>**Fund** | **Mid Cap** <br>**Value** <br>**Fund** | **Mid Cap** <br>**Value** <br>**Fund** | **Small-Mid** <br>**Cap Core** <br>**Fund** | **Small-Mid** <br>**Cap Core** <br>**Fund** |
|  | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** |
| ***Operations*** |  |  |  |  |  |  |  |  |
| Net investment income (loss) | $(1118)<br>| &nbsp;&nbsp; $(974)<br>| &nbsp;&nbsp; $(5155)<br>| &nbsp;&nbsp; $(3065)<br>| &nbsp;&nbsp; $18 | &nbsp;&nbsp; $22 | &nbsp;&nbsp; $198 | &nbsp;&nbsp; $302 |
| Net realized gain (loss) on <br> investments, and other assets and <br> liabilities<br>| 56339 | &nbsp;&nbsp; 64672 | &nbsp;&nbsp; 207500 | &nbsp;&nbsp; 319531 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; 48 | &nbsp;&nbsp; 1181 | &nbsp;&nbsp; 28376 |
| Change in net unrealized appreciation <br> (depreciation) on investments, and <br> other assets and liabilities<br>| (32212)<br>| &nbsp;&nbsp; (12938)<br>| &nbsp;&nbsp; 96681 | &nbsp;&nbsp; 193373 | &nbsp;&nbsp; 76 | &nbsp;&nbsp; 100 | &nbsp;&nbsp; 802 | &nbsp;&nbsp; (6005)<br>|
| Net increase (decrease) in net assets <br> resulting from operations<br>| 23009 | &nbsp;&nbsp; 50760 | &nbsp;&nbsp; 299026 | &nbsp;&nbsp; 509839 | &nbsp;&nbsp; 108 | &nbsp;&nbsp; 170 | &nbsp;&nbsp; 2181 | &nbsp;&nbsp; 22673 |
| ***Distributions to shareholders*** |  |  |  |  |  |  |  |  |
| Class N | (8871)<br>| &nbsp;&nbsp; (8100)<br>| &nbsp;&nbsp; (11487)<br>| &nbsp;&nbsp; (10648)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I | (35654)<br>| &nbsp;&nbsp; (34685)<br>| &nbsp;&nbsp; (151139)<br>| &nbsp;&nbsp; (114762)<br>| &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; (1279)<br>| &nbsp;&nbsp; (1373)<br>|
| Class R6 | (8348)<br>| &nbsp;&nbsp; (9050)<br>| &nbsp;&nbsp; (48128)<br>| &nbsp;&nbsp; (35091)<br>| &nbsp;&nbsp; (19)<br>| &nbsp;&nbsp; (21)<br>| &nbsp;&nbsp; (2352)<br>| &nbsp;&nbsp; (1043)<br>|
| Total distributions | (52873)<br>| &nbsp;&nbsp; (51835)<br>| &nbsp;&nbsp; (210754)<br>| &nbsp;&nbsp; (160501)<br>| &nbsp;&nbsp; (20)<br>| &nbsp;&nbsp; (22)<br>| &nbsp;&nbsp; (3631)<br>| &nbsp;&nbsp; (2416)<br>|
| ***Capital stock transactions*** |  |  |  |  |  |  |  |  |
| Proceeds from sales of shares | 8569 | &nbsp;&nbsp; 12776 | &nbsp;&nbsp; 405349 | &nbsp;&nbsp; 1325216 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 132 | &nbsp;&nbsp; 68856 | &nbsp;&nbsp; 40728 |
| Shares issued in reinvestment of <br> income dividends and capital gain <br> distributions<br>| 50826 | &nbsp;&nbsp; 49121 | &nbsp;&nbsp; 188267 | &nbsp;&nbsp; 144462 | &nbsp;&nbsp; 20 | &nbsp;&nbsp; 22 | &nbsp;&nbsp; 3478 | &nbsp;&nbsp; 2288 |
| Less cost of shares redeemed | (51082)<br>| &nbsp;&nbsp; (50298)<br>| &nbsp;&nbsp; (855382)<br>| &nbsp;&nbsp; (649895)<br>| &nbsp;&nbsp; (513)<br>| &nbsp;&nbsp; (3)<br>| &nbsp;&nbsp; (72406)<br>| &nbsp;&nbsp; (134802)<br>|
| Net increase (decrease) in net <br> assets resulting from capital <br> share transactions<br>| 8313 | &nbsp;&nbsp; 11599 | &nbsp;&nbsp; (261766)<br>| &nbsp;&nbsp; 819783 | &nbsp;&nbsp; (492)<br>| &nbsp;&nbsp; 151 | &nbsp;&nbsp; (72)<br>| &nbsp;&nbsp; (91786)<br>|
| Net increase (decrease) in net assets | (21551)<br>| &nbsp;&nbsp; 10524 | &nbsp;&nbsp; (173494)<br>| &nbsp;&nbsp; 1169121 | &nbsp;&nbsp; (404)<br>| &nbsp;&nbsp; 299 | &nbsp;&nbsp; (1522)<br>| &nbsp;&nbsp; (71529)<br>|
| ***Net Assets*** |  |  |  |  |  |  |  |  |
| Beginning of period | 249916 | &nbsp;&nbsp; 239392 | &nbsp;&nbsp; 2803223 | &nbsp;&nbsp; 1634102 | &nbsp;&nbsp; 1757 | &nbsp;&nbsp; 1458 | &nbsp;&nbsp; 124651 | &nbsp;&nbsp; 196180 |
| End of period | $228365 | &nbsp;&nbsp; $249916 | &nbsp;&nbsp; $2629729 | &nbsp;&nbsp; $2803223 | &nbsp;&nbsp; $1353 | &nbsp;&nbsp; $1757 | &nbsp;&nbsp; $123129 | &nbsp;&nbsp; $124651 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**66**

*Annual*

------

**Statements of Assets and Liabilities**

**As of December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Small-Mid Cap** <br>**Growth Fund**<br>| **Small-Mid Cap** <br>**Value Fund**<br>| **Small Cap** <br>**Growth Fund**<br>| **Small Cap** <br>**Value Fund**<br>|
| ***Assets*** |  |  |  |  |
| Investments in securities, at cost | $1050248 | &nbsp;&nbsp; $3193 | &nbsp;&nbsp; $873571 | &nbsp;&nbsp; $781924 |
| Investments in securities, at value | $1235029 | &nbsp;&nbsp; $3494 | &nbsp;&nbsp; $987407 | &nbsp;&nbsp; $919455 |
| Receivable for securities sold | 19412 | &nbsp;&nbsp; — | &nbsp;&nbsp; 112 | &nbsp;&nbsp; — |
| Receivable for fund shares sold | 186 | &nbsp;&nbsp; — | &nbsp;&nbsp; 2804 | &nbsp;&nbsp; 307 |
| Receivable from Adviser | 100 | &nbsp;&nbsp; 13 | &nbsp;&nbsp; 116 | &nbsp;&nbsp; 11 |
| Dividends and interest receivable | 316 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 410 | &nbsp;&nbsp; 1251 |
| Total assets | 1255043 | &nbsp;&nbsp; 3509 | &nbsp;&nbsp; 990849 | &nbsp;&nbsp; 921024 |
| ***Liabilities*** |  |  |  |  |
| Payable for securities purchased |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 2001 | &nbsp;&nbsp; 514 |
| Payable for fund shares redeemed | 716 | &nbsp;&nbsp; — | &nbsp;&nbsp; 683 | &nbsp;&nbsp; 262 |
| Management fee payable | 1041 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 806 | &nbsp;&nbsp; 597 |
| Distribution fee payable | 14 | &nbsp;&nbsp; — | &nbsp;&nbsp; 24 | &nbsp;&nbsp; — |
| Other payables and accrued expenses | 321 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 235 | &nbsp;&nbsp; 195 |
| Total liabilities | 2092 | &nbsp;&nbsp; 52 | &nbsp;&nbsp; 3749 | &nbsp;&nbsp; 1568 |
| Net assets | $1252951 | &nbsp;&nbsp; $3457 | &nbsp;&nbsp; $987100 | &nbsp;&nbsp; $919456 |
| ***Capital*** |  |  |  |  |
| Composition of net assets |  |  |  |  |
| Paid in capital | $1059765 | &nbsp;&nbsp; $3302 | &nbsp;&nbsp; $887360 | &nbsp;&nbsp; $858242 |
| Total distributable earnings (loss) | 193186 | &nbsp;&nbsp; 155 | &nbsp;&nbsp; 99740 | &nbsp;&nbsp; 61214 |
| Net assets | $1252951 | &nbsp;&nbsp; $3457 | &nbsp;&nbsp; $987100 | &nbsp;&nbsp; $919456 |
| Class N shares |  |  |  |  |
| Net assets | $62475 | &nbsp;&nbsp; — | &nbsp;&nbsp; $110716 | &nbsp;&nbsp; $1978 |
| Shares outstanding | 2536603 | &nbsp;&nbsp; — | &nbsp;&nbsp; 4068603 | &nbsp;&nbsp; 66271 |
| Net asset value per share | $24.63 | &nbsp;&nbsp; — | &nbsp;&nbsp; $27.21 | &nbsp;&nbsp; $29.85 |
| Class I shares |  |  |  |  |
| Net assets | $788511 | &nbsp;&nbsp; $124 | &nbsp;&nbsp; $546225 | &nbsp;&nbsp; $547178 |
| Shares outstanding | 28746835 | &nbsp;&nbsp; 11141 | &nbsp;&nbsp; 16133955 | &nbsp;&nbsp; 18363136 |
| Net asset value per share | $27.43 | &nbsp;&nbsp; $11.15 | &nbsp;&nbsp; $33.86 | &nbsp;&nbsp; $29.80 |
| Class R6 shares |  |  |  |  |
| Net assets | $401965 | &nbsp;&nbsp; $3333 | &nbsp;&nbsp; $330159 | &nbsp;&nbsp; $370300 |
| Shares outstanding | 14579375 | &nbsp;&nbsp; 299127 | &nbsp;&nbsp; 9699642 | &nbsp;&nbsp; 12432379 |
| Net asset value per share | $27.57 | &nbsp;&nbsp; $11.14 | &nbsp;&nbsp; $34.04 | &nbsp;&nbsp; $29.79 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**67**

*William Blair Funds*

------

**Statements of Operations**

**For the Year Ended December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Small-Mid Cap** <br>**Growth Fund**<br>| **Small-Mid Cap** <br>**Value Fund**<br>| **Small Cap** <br>**Growth Fund**<br>| **Small Cap** <br>**Value Fund**<br>|
| ***Investment income*** |  |  |  |  |
| Dividends | $7337 | &nbsp;&nbsp; $60 | &nbsp;&nbsp; $5414 | &nbsp;&nbsp; $19726 |
| Less foreign tax withheld | (157)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (98)<br>| &nbsp;&nbsp; (4)<br>|
| Interest | 460 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 430 | &nbsp;&nbsp; 405 |
| Total income | 7640 | &nbsp;&nbsp; 61 | &nbsp;&nbsp; 5746 | &nbsp;&nbsp; 20127 |
| ***Expenses*** |  |  |  |  |
| Management fees | 13759 | &nbsp;&nbsp; 26 | &nbsp;&nbsp; 8711 | &nbsp;&nbsp; 8292 |
| Distribution fees | 181 | &nbsp;&nbsp; — | &nbsp;&nbsp; 310 | &nbsp;&nbsp; 5 |
| Custodian fees | 151 | &nbsp;&nbsp; 59 | &nbsp;&nbsp; 74 | &nbsp;&nbsp; 83 |
| Transfer agent fees | 133 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 174 | &nbsp;&nbsp; 70 |
| Sub-transfer agent fees |  |  |  |  |
| Class N | 96 | &nbsp;&nbsp; — | &nbsp;&nbsp; 167 | &nbsp;&nbsp; 2 |
| Class I | 1233 | &nbsp;&nbsp; — | &nbsp;&nbsp; 622 | &nbsp;&nbsp; 769 |
| Professional fees | 154 | &nbsp;&nbsp; 31 | &nbsp;&nbsp; 111 | &nbsp;&nbsp; 128 |
| Registration fees | 59 | &nbsp;&nbsp; 33 | &nbsp;&nbsp; 64 | &nbsp;&nbsp; 60 |
| Shareholder reporting fees | 40 | &nbsp;&nbsp; 10 | &nbsp;&nbsp; 64 | &nbsp;&nbsp; 45 |
| Trustee fees | 157 | &nbsp;&nbsp; — | &nbsp;&nbsp; 86 | &nbsp;&nbsp; 117 |
| Other expenses | 56 | &nbsp;&nbsp; 4 | &nbsp;&nbsp; 31 | &nbsp;&nbsp; 41 |
| Total expenses before expense limitation | 16019 | &nbsp;&nbsp; 164 | &nbsp;&nbsp; 10414 | &nbsp;&nbsp; 9612 |
| Expenses waived or reimbursed by the Adviser |  |  |  |  |
| Class N | (97)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (186)<br>| &nbsp;&nbsp; — |
| Class I | (1246)<br>| &nbsp;&nbsp; (5)<br>| &nbsp;&nbsp; (703)<br>| &nbsp;&nbsp; (233)<br>|
| Class R6 | (219)<br>| &nbsp;&nbsp; (132)<br>| &nbsp;&nbsp; (176)<br>| &nbsp;&nbsp; — |
| Total expenses waived or reimbursed by the Adviser | (1562)<br>| &nbsp;&nbsp; (137)<br>| &nbsp;&nbsp; (1065)<br>| &nbsp;&nbsp; (233)<br>|
| Net expenses | 14457 | &nbsp;&nbsp; 27 | &nbsp;&nbsp; 9349 | &nbsp;&nbsp; 9379 |
| Net investment income (loss) | (6817)<br>| &nbsp;&nbsp; 34 | &nbsp;&nbsp; (3603)<br>| &nbsp;&nbsp; 10748 |
| ***Realized and unrealized gain (loss)*** |  |  |  |  |
| Net realized gain (loss) on transactions from: |  |  |  |  |
| Investments in securities | 52454 | &nbsp;&nbsp; (131)<br>| &nbsp;&nbsp; 54744 | &nbsp;&nbsp; (67160)<br>|
| Foreign currency transactions | 5 | &nbsp;&nbsp; — | &nbsp;&nbsp; 2 | &nbsp;&nbsp; — |
| Total net realized gain (loss) | 52459 | &nbsp;&nbsp; (131)<br>| &nbsp;&nbsp; 54746 | &nbsp;&nbsp; (67160)<br>|
| Change in net unrealized appreciation (depreciation) of: |  |  |  |  |
| Investments in securities | (58787)<br>| &nbsp;&nbsp; 204 | &nbsp;&nbsp; (23327)<br>| &nbsp;&nbsp; 65055 |
| Change in net unrealized appreciation (depreciation) | (58787)<br>| &nbsp;&nbsp; 204 | &nbsp;&nbsp; (23327)<br>| &nbsp;&nbsp; 65055 |
| **Net increase (decrease) in net assets resulting from operations** | $(13145)<br>| &nbsp;&nbsp; $107 | &nbsp;&nbsp; $27816 | &nbsp;&nbsp; $8643 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**68**

*Annual*

------

**Statements of Changes in Net Assets**

**For the Years Ended December 31, 2025 and 2024** *(dollar amounts in thousands)*

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Small-Mid Cap** <br>**Growth Fund** | **Small-Mid Cap** <br>**Growth Fund** | **Small-Mid Cap** <br>**Value Fund** | **Small-Mid Cap** <br>**Value Fund** | **Small Cap** <br>**Growth Fund** | **Small Cap** <br>**Growth Fund** | **Small Cap** <br>**Value Fund** | **Small Cap** <br>**Value Fund** |
|  | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** |
| ***Operations*** |  |  |  |  |  |  |  |  |
| Net investment income (loss) | $(6817)<br>| &nbsp;&nbsp; $(8266)<br>| &nbsp;&nbsp; $34 | &nbsp;&nbsp; $35 | &nbsp;&nbsp; $(3603)<br>| &nbsp;&nbsp; $(3917)<br>| &nbsp;&nbsp; $10748 | &nbsp;&nbsp; $13877 |
| Net realized gain (loss) on <br> investments, and other assets <br> and liabilities<br>| 52459 | &nbsp;&nbsp; 282080 | &nbsp;&nbsp; (131)<br>| &nbsp;&nbsp; 52 | &nbsp;&nbsp; 54746 | &nbsp;&nbsp; 125143 | &nbsp;&nbsp; (67160)<br>| &nbsp;&nbsp; 58844 |
| Change in net unrealized <br> appreciation (depreciation) on <br> investments, and other assets <br> and liabilities<br>| (58787)<br>| &nbsp;&nbsp; (68324)<br>| &nbsp;&nbsp; 204 | &nbsp;&nbsp; 7 | &nbsp;&nbsp; (23327)<br>| &nbsp;&nbsp; 26674 | &nbsp;&nbsp; 65055 | &nbsp;&nbsp; (32001)<br>|
| Net increase (decrease) in net <br> assets resulting from <br> operations<br>| (13145)<br>| &nbsp;&nbsp; 205490 | &nbsp;&nbsp; 107 | &nbsp;&nbsp; 94 | &nbsp;&nbsp; 27816 | &nbsp;&nbsp; 147900 | &nbsp;&nbsp; 8643 | &nbsp;&nbsp; 40720 |
| ***Distributions to shareholders*** |  |  |  |  |  |  |  |  |
| Class N | (1923)<br>| &nbsp;&nbsp; (11388)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (9662)<br>| &nbsp;&nbsp; (15272)<br>| &nbsp;&nbsp; (40)<br>| &nbsp;&nbsp; (78)<br>|
| Class I | (21738)<br>| &nbsp;&nbsp; (139167)<br>| &nbsp;&nbsp; (2)<br>| &nbsp;&nbsp; (2)<br>| &nbsp;&nbsp; (39085)<br>| &nbsp;&nbsp; (48903)<br>| &nbsp;&nbsp; (12270)<br>| &nbsp;&nbsp; (28020)<br>|
| Class R6 | (11454)<br>| &nbsp;&nbsp; (62363)<br>| &nbsp;&nbsp; (51)<br>| &nbsp;&nbsp; (59)<br>| &nbsp;&nbsp; (23399)<br>| &nbsp;&nbsp; (24529)<br>| &nbsp;&nbsp; (8642)<br>| &nbsp;&nbsp; (23627)<br>|
| Total distributions | (35115)<br>| &nbsp;&nbsp; (212918)<br>| &nbsp;&nbsp; (53)<br>| &nbsp;&nbsp; (61)<br>| &nbsp;&nbsp; (72146)<br>| &nbsp;&nbsp; (88704)<br>| &nbsp;&nbsp; (20952)<br>| &nbsp;&nbsp; (51725)<br>|
| ***Capital stock transactions*** |  |  |  |  |  |  |  |  |
| Proceeds from sales of shares | 158518 | &nbsp;&nbsp; 363460 | &nbsp;&nbsp; — | &nbsp;&nbsp; 3030 | &nbsp;&nbsp; 330061 | &nbsp;&nbsp; 228487 | &nbsp;&nbsp; 120096 | &nbsp;&nbsp; 297778 |
| Shares issued in reinvestment of <br> income dividends and capital <br> gain distributions<br>| 34300 | &nbsp;&nbsp; 206117 | &nbsp;&nbsp; 54 | &nbsp;&nbsp; 62 | &nbsp;&nbsp; 70789 | &nbsp;&nbsp; 86482 | &nbsp;&nbsp; 20619 | &nbsp;&nbsp; 43987 |
| Less cost of shares redeemed | (778839)<br>| &nbsp;&nbsp; (670112)<br>| &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; (1356)<br>| &nbsp;&nbsp; (286791)<br>| &nbsp;&nbsp; (204705)<br>| &nbsp;&nbsp; (560686)<br>| &nbsp;&nbsp; (287070)<br>|
| Net increase (decrease) in net <br> assets resulting from capital <br> share transactions<br>| (586021)<br>| &nbsp;&nbsp; (100535)<br>| &nbsp;&nbsp; 53 | &nbsp;&nbsp; 1736 | &nbsp;&nbsp; 114059 | &nbsp;&nbsp; 110264 | &nbsp;&nbsp; (419971)<br>| &nbsp;&nbsp; 54695 |
| Net increase (decrease) in net <br> assets<br>| (634281)<br>| &nbsp;&nbsp; (107963)<br>| &nbsp;&nbsp; 107 | &nbsp;&nbsp; 1769 | &nbsp;&nbsp; 69729 | &nbsp;&nbsp; 169460 | &nbsp;&nbsp; (432280)<br>| &nbsp;&nbsp; 43690 |
| ***Net Assets*** |  |  |  |  |  |  |  |  |
| Beginning of period | 1887232 | &nbsp;&nbsp; 1995195 | &nbsp;&nbsp; 3350 | &nbsp;&nbsp; 1581 | &nbsp;&nbsp; 917371 | &nbsp;&nbsp; 747911 | &nbsp;&nbsp; 1351736 | &nbsp;&nbsp; 1308046 |
| End of period | $1252951 | &nbsp;&nbsp; $1887232 | &nbsp;&nbsp; $3457 | &nbsp;&nbsp; $3350 | &nbsp;&nbsp; $987100 | &nbsp;&nbsp; $917371 | &nbsp;&nbsp; $919456 | &nbsp;&nbsp; $1351736 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**69**

*William Blair Funds*

------

**Statements of Assets and Liabilities**

**As of December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Global** <br>**Leaders** <br>**Fund**<br>| **International** <br>**Leaders** <br>**Fund**<br>| **International** <br>**Growth** <br>**Fund**<br>| **Institutional** <br>**International** <br>**Growth** <br>**Fund**<br>|
| ***Assets*** |  |  |  |  |
| Investments in securities, at cost | $14868 | &nbsp;&nbsp; $852702 | &nbsp;&nbsp; $844025 | &nbsp;&nbsp; $629433 |
| Investments in securities, at value | $17870 | &nbsp;&nbsp; $1110778 | &nbsp;&nbsp; $1125010 | &nbsp;&nbsp; $834120 |
| Cash |  | &nbsp;&nbsp; 99 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Foreign currency, at value (cost —;$105;$622;$77) |  | &nbsp;&nbsp; 104 | &nbsp;&nbsp; 622 | &nbsp;&nbsp; 77 |
| Receivable for securities sold | 206 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1170 | &nbsp;&nbsp; 968 |
| Receivable for fund shares sold | 8 | &nbsp;&nbsp; 1554 | &nbsp;&nbsp; 1369 | &nbsp;&nbsp; 21 |
| Receivable from Adviser | 119 | &nbsp;&nbsp; 118 | &nbsp;&nbsp; 174 | &nbsp;&nbsp; 65 |
| Dividends and interest receivable | 98 | &nbsp;&nbsp; 2233 | &nbsp;&nbsp; 4218 | &nbsp;&nbsp; 2546 |
| Total assets | 18301 | &nbsp;&nbsp; 1114886 | &nbsp;&nbsp; 1132563 | &nbsp;&nbsp; 837797 |
| ***Liabilities*** |  |  |  |  |
| Payable for securities purchased |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 7844 | &nbsp;&nbsp; 1342 |
| Payable for fund shares redeemed |  | &nbsp;&nbsp; 17593 | &nbsp;&nbsp; 680 | &nbsp;&nbsp; — |
| Payable to custodian | 53 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Management fee payable | 15 | &nbsp;&nbsp; 811 | &nbsp;&nbsp; 840 | &nbsp;&nbsp; 654 |
| Distribution fee payable |  | &nbsp;&nbsp; 5 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; — |
| Foreign capital gains tax liability |  | &nbsp;&nbsp; 803 | &nbsp;&nbsp; 1424 | &nbsp;&nbsp; 1044 |
| Other payables and accrued expenses | 172 | &nbsp;&nbsp; 353 | &nbsp;&nbsp; 499 | &nbsp;&nbsp; 217 |
| Total liabilities | 240 | &nbsp;&nbsp; 19565 | &nbsp;&nbsp; 11338 | &nbsp;&nbsp; 3257 |
| Net assets | $18061 | &nbsp;&nbsp; $1095321 | &nbsp;&nbsp; $1121225 | &nbsp;&nbsp; $834540 |
| ***Capital*** |  |  |  |  |
| Composition of net assets |  |  |  |  |
| Paid in capital | $15262 | &nbsp;&nbsp; $831949 | &nbsp;&nbsp; $813105 | &nbsp;&nbsp; $607478 |
| Total distributable earnings (loss) | 2799 | &nbsp;&nbsp; 263372 | &nbsp;&nbsp; 308120 | &nbsp;&nbsp; 227062 |
| Net assets | $18061 | &nbsp;&nbsp; $1095321 | &nbsp;&nbsp; $1121225 | &nbsp;&nbsp; $834540 |
| Class N shares |  |  |  |  |
| Net assets | $1892 | &nbsp;&nbsp; $24666 | &nbsp;&nbsp; $229980 | &nbsp;&nbsp; — |
| Shares outstanding | 295545 | &nbsp;&nbsp; 1125935 | &nbsp;&nbsp; 8848950 | &nbsp;&nbsp; — |
| Net asset value per share | $6.40 | &nbsp;&nbsp; $21.91 | &nbsp;&nbsp; $25.99 | &nbsp;&nbsp; — |
| Class I shares |  |  |  |  |
| Net assets | $13894 | &nbsp;&nbsp; $645147 | &nbsp;&nbsp; $802959 | &nbsp;&nbsp; — |
| Shares outstanding | 2099492 | &nbsp;&nbsp; 29229448 | &nbsp;&nbsp; 29604974 | &nbsp;&nbsp; — |
| Net asset value per share | $6.62 | &nbsp;&nbsp; $22.07 | &nbsp;&nbsp; $27.12 | &nbsp;&nbsp; — |
| Class R6 shares |  |  |  |  |
| Net assets | $2275 | &nbsp;&nbsp; $425508 | &nbsp;&nbsp; $88286 | &nbsp;&nbsp; — |
| Shares outstanding | 343864 | &nbsp;&nbsp; 19264406 | &nbsp;&nbsp; 3251735 | &nbsp;&nbsp; — |
| Net asset value per share | $6.62 | &nbsp;&nbsp; $22.09 | &nbsp;&nbsp; $27.15 | &nbsp;&nbsp; — |
| Institutional shares |  |  |  |  |
| Net assets |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; $834540 |
| Shares outstanding |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 58115326 |
| Net asset value per share |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; $14.36 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**70**

*Annual*

------

**Statements of Operations**

**For the Year Ended December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Global** <br>**Leaders** <br>**Fund**<br>| **International** <br>**Leaders** <br>**Fund**<br>| **International** <br>**Growth** <br>**Fund**<br>| **Institutional** <br>**International** <br>**Growth** <br>**Fund**<br>|
| ***Investment income*** |  |  |  |  |
| Dividends | $483 | &nbsp;&nbsp; $19644 | &nbsp;&nbsp; $24279 | &nbsp;&nbsp; $17886 |
| Less foreign tax withheld | (35)<br>| &nbsp;&nbsp; (2200)<br>| &nbsp;&nbsp; (2554)<br>| &nbsp;&nbsp; (1836)<br>|
| Interest | 13 | &nbsp;&nbsp; 294 | &nbsp;&nbsp; 255 | &nbsp;&nbsp; 239 |
| Other income |  | &nbsp;&nbsp; 568 | &nbsp;&nbsp; 170 | &nbsp;&nbsp; 115 |
| Total income | 461 | &nbsp;&nbsp; 18306 | &nbsp;&nbsp; 22150 | &nbsp;&nbsp; 16404 |
| ***Expenses*** |  |  |  |  |
| Management fees | 365 | &nbsp;&nbsp; 9768 | &nbsp;&nbsp; 11472 | &nbsp;&nbsp; 8234 |
| Distribution fees | 7 | &nbsp;&nbsp; 67 | &nbsp;&nbsp; 627 | &nbsp;&nbsp; — |
| Custodian fees | 108 | &nbsp;&nbsp; 198 | &nbsp;&nbsp; 327 | &nbsp;&nbsp; 247 |
| Transfer agent fees | 9 | &nbsp;&nbsp; 80 | &nbsp;&nbsp; 96 | &nbsp;&nbsp; 36 |
| Sub-transfer agent fees |  |  |  |  |
| Class N | 3 | &nbsp;&nbsp; 30 | &nbsp;&nbsp; 360 | &nbsp;&nbsp; — |
| Class I | 34 | &nbsp;&nbsp; 746 | &nbsp;&nbsp; 1016 | &nbsp;&nbsp; — |
| Professional fees | 147 | &nbsp;&nbsp; 156 | &nbsp;&nbsp; 196 | &nbsp;&nbsp; 154 |
| Registration fees | 45 | &nbsp;&nbsp; 63 | &nbsp;&nbsp; 59 | &nbsp;&nbsp; 28 |
| Shareholder reporting fees | 15 | &nbsp;&nbsp; 54 | &nbsp;&nbsp; 57 | &nbsp;&nbsp; 12 |
| Trustee fees | 5 | &nbsp;&nbsp; 107 | &nbsp;&nbsp; 124 | &nbsp;&nbsp; 84 |
| Other expenses | 5 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 29 |
| Total expenses before expense limitation | 743 | &nbsp;&nbsp; 11305 | &nbsp;&nbsp; 14378 | &nbsp;&nbsp; 8824 |
| Expenses waived or reimbursed by the Adviser |  |  |  |  |
| Class N | (22)<br>| &nbsp;&nbsp; (33)<br>| &nbsp;&nbsp; (410)<br>| &nbsp;&nbsp; — |
| Class I | (296)<br>| &nbsp;&nbsp; (811)<br>| &nbsp;&nbsp; (1199)<br>| &nbsp;&nbsp; — |
| Class R6 | (35)<br>| &nbsp;&nbsp; (309)<br>| &nbsp;&nbsp; (74)<br>| &nbsp;&nbsp; — |
| Institutional |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (590)<br>|
| Total expenses waived or reimbursed by the Adviser | (353)<br>| &nbsp;&nbsp; (1153)<br>| &nbsp;&nbsp; (1683)<br>| &nbsp;&nbsp; (590)<br>|
| Net expenses | 390 | &nbsp;&nbsp; 10152 | &nbsp;&nbsp; 12695 | &nbsp;&nbsp; 8234 |
| Net investment income (loss) | 71 | &nbsp;&nbsp; 8154 | &nbsp;&nbsp; 9455 | &nbsp;&nbsp; 8170 |
| ***Realized and unrealized gain (loss)*** |  |  |  |  |
| Net realized gain (loss) on transactions from: |  |  |  |  |
| Investments in securities (net of foreign capital gains tax paid $—; $793; <br> $1,574; $1,099)<br>| 15929 | &nbsp;&nbsp; 141776 | &nbsp;&nbsp; 219702 | &nbsp;&nbsp; 131504 |
| Foreign currency transactions | (6)<br>| &nbsp;&nbsp; (832)<br>| &nbsp;&nbsp; (670)<br>| &nbsp;&nbsp; (449)<br>|
| Total net realized gain | 15923 | &nbsp;&nbsp; 140944 | &nbsp;&nbsp; 219032 | &nbsp;&nbsp; 131055 |
| Change in net unrealized appreciation (depreciation) of: |  |  |  |  |
| Investments in securities (net of foreign capital gains tax accrual $—; <br> $407; $(1270); $(908))<br>| (9618)<br>| &nbsp;&nbsp; 93425 | &nbsp;&nbsp; (18493)<br>| &nbsp;&nbsp; 16291 |
| Foreign currency translations | 10 | &nbsp;&nbsp; 206 | &nbsp;&nbsp; 611 | &nbsp;&nbsp; 195 |
| Change in net unrealized appreciation (depreciation) | (9608)<br>| &nbsp;&nbsp; 93631 | &nbsp;&nbsp; (17882)<br>| &nbsp;&nbsp; 16486 |
| **Net increase (decrease) in net assets resulting from operations** | $6386 | &nbsp;&nbsp; $242729 | &nbsp;&nbsp; $210605 | &nbsp;&nbsp; $155711 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**71**

*William Blair Funds*

------

**Statements of Changes in Net Assets**

**For the Years Ended December 31, 2025 and 2024** *(dollar amounts in thousands)*

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Global** <br>**Leaders** <br>**Fund** | **Global** <br>**Leaders** <br>**Fund** | **International** <br>**Leaders** <br>**Fund** | **International** <br>**Leaders** <br>**Fund** | **International** <br>**Growth** <br>**Fund** | **International** <br>**Growth** <br>**Fund** | **Institutional** <br>**International** <br>**Growth** <br>**Fund** | **Institutional** <br>**International** <br>**Growth** <br>**Fund** |
|  | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** |
| ***Operations*** |  |  |  |  |  |  |  |  |
| Net investment income (loss) | $71 | &nbsp;&nbsp; $102 | &nbsp;&nbsp; $8154 | &nbsp;&nbsp; $6189 | &nbsp;&nbsp; $9455 | &nbsp;&nbsp; $7770 | &nbsp;&nbsp; $8170 | &nbsp;&nbsp; $5966 |
| Net realized gain (loss) on <br> investments, and other <br> assets and liabilities<br>| 15923 | &nbsp;&nbsp; 32026 | &nbsp;&nbsp; 140944 | &nbsp;&nbsp; 70697 | &nbsp;&nbsp; 219032 | &nbsp;&nbsp; 106008 | &nbsp;&nbsp; 131055 | &nbsp;&nbsp; 66033 |
| Change in net unrealized <br> appreciation (depreciation) <br> on investments, and other <br> assets and liabilities<br>| (9608)<br>| &nbsp;&nbsp; (24292)<br>| &nbsp;&nbsp; 93631 | &nbsp;&nbsp; (86495)<br>| &nbsp;&nbsp; (17882)<br>| &nbsp;&nbsp; (78893)<br>| &nbsp;&nbsp; 16486 | &nbsp;&nbsp; (48704)<br>|
| Net increase (decrease) in <br> net assets resulting from <br> operations<br>| 6386 | &nbsp;&nbsp; 7836 | &nbsp;&nbsp; 242729 | &nbsp;&nbsp; (9609)<br>| &nbsp;&nbsp; 210605 | &nbsp;&nbsp; 34885 | &nbsp;&nbsp; 155711 | &nbsp;&nbsp; 23295 |
| ***Distributions to shareholders*** |  |  |  |  |  |  |  |  |
| Class N | (1255)<br>| &nbsp;&nbsp; (1439)<br>| &nbsp;&nbsp; (1777)<br>| &nbsp;&nbsp; (75)<br>| &nbsp;&nbsp; (40226)<br>| &nbsp;&nbsp; (18465)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I | (7676)<br>| &nbsp;&nbsp; (16809)<br>| &nbsp;&nbsp; (49020)<br>| &nbsp;&nbsp; (3154)<br>| &nbsp;&nbsp; (134347)<br>| &nbsp;&nbsp; (70112)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class R6 | (1231)<br>| &nbsp;&nbsp; (4655)<br>| &nbsp;&nbsp; (34888)<br>| &nbsp;&nbsp; (3581)<br>| &nbsp;&nbsp; (15140)<br>| &nbsp;&nbsp; (8931)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Institutional |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (103491)<br>| &nbsp;&nbsp; (62543)<br>|
| Total distributions | (10162)<br>| &nbsp;&nbsp; (22903)<br>| &nbsp;&nbsp; (85685)<br>| &nbsp;&nbsp; (6810)<br>| &nbsp;&nbsp; (189713)<br>| &nbsp;&nbsp; (97508)<br>| &nbsp;&nbsp; (103491)<br>| &nbsp;&nbsp; (62543)<br>|
| ***Capital stock transactions*** |  |  |  |  |  |  |  |  |
| Proceeds from sales of <br> shares<br>| 4069 | &nbsp;&nbsp; 2729 | &nbsp;&nbsp; 190239 | &nbsp;&nbsp; 317659 | &nbsp;&nbsp; 129576 | &nbsp;&nbsp; 148876 | &nbsp;&nbsp; 57536 | &nbsp;&nbsp; 66691 |
| Shares issued in <br> reinvestment of income <br> dividends and capital gain <br> distributions<br>| 10043 | &nbsp;&nbsp; 22380 | &nbsp;&nbsp; 84436 | &nbsp;&nbsp; 6414 | &nbsp;&nbsp; 184071 | &nbsp;&nbsp; 92490 | &nbsp;&nbsp; 102442 | &nbsp;&nbsp; 61982 |
| Less cost of shares redeemed | (46452)<br>| &nbsp;&nbsp; (56320)<br>| &nbsp;&nbsp; (497064)<br>| &nbsp;&nbsp; (230924)<br>| &nbsp;&nbsp; (576446)<br>| &nbsp;&nbsp; (246715)<br>| &nbsp;&nbsp; (274702)<br>| &nbsp;&nbsp; (121855)<br>|
| Net increase (decrease) in <br> net assets resulting from <br> capital share <br> transactions<br>| (32340)<br>| &nbsp;&nbsp; (31211)<br>| &nbsp;&nbsp; (222389)<br>| &nbsp;&nbsp; 93149 | &nbsp;&nbsp; (262799)<br>| &nbsp;&nbsp; (5349)<br>| &nbsp;&nbsp; (114724)<br>| &nbsp;&nbsp; 6818 |
| Net increase (decrease) in <br> net assets<br>| (36116)<br>| &nbsp;&nbsp; (46278)<br>| &nbsp;&nbsp; (65345)<br>| &nbsp;&nbsp; 76730 | &nbsp;&nbsp; (241907)<br>| &nbsp;&nbsp; (67972)<br>| &nbsp;&nbsp; (62504)<br>| &nbsp;&nbsp; (32430)<br>|
| ***Net Assets*** |  |  |  |  |  |  |  |  |
| Beginning of period | 54177 | &nbsp;&nbsp; 100455 | &nbsp;&nbsp; 1160666 | &nbsp;&nbsp; 1083936 | &nbsp;&nbsp; 1363132 | &nbsp;&nbsp; 1431104 | &nbsp;&nbsp; 897044 | &nbsp;&nbsp; 929474 |
| End of period | $18061 | &nbsp;&nbsp; $54177 | &nbsp;&nbsp; $1095321 | &nbsp;&nbsp; $1160666 | &nbsp;&nbsp; $1121225 | &nbsp;&nbsp; $1363132 | &nbsp;&nbsp; $834540 | &nbsp;&nbsp; $897044 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**72**

*Annual*

------

**Statements of Assets and Liabilities**

**As of December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **International** <br>**Small Cap** <br>**Growth** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**Leaders** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**Growth** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**ex China** <br>**Growth Fund**<br>|
| ***Assets*** |  |  |  |  |
| Investments in securities, at cost | $103932 | &nbsp;&nbsp; $74001 | &nbsp;&nbsp; $714667 | &nbsp;&nbsp; $43361 |
| Investments in securities, at value | $130048 | &nbsp;&nbsp; $96253 | &nbsp;&nbsp; $1019670 | &nbsp;&nbsp; $57226 |
| Foreign currency, at value (cost $38;$25;$2,412;$86) | 38 | &nbsp;&nbsp; 25 | &nbsp;&nbsp; 2420 | &nbsp;&nbsp; 86 |
| Receivable for securities sold | 35 | &nbsp;&nbsp; 1301 | &nbsp;&nbsp; — | &nbsp;&nbsp; 38 |
| Receivable for fund shares sold | 6 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 1379 | &nbsp;&nbsp; 515 |
| Receivable from Adviser | 42 | &nbsp;&nbsp; 19 | &nbsp;&nbsp; 120 | &nbsp;&nbsp; 44 |
| Dividends and interest receivable | 536 | &nbsp;&nbsp; 147 | &nbsp;&nbsp; 1841 | &nbsp;&nbsp; 89 |
| Total assets | 130705 | &nbsp;&nbsp; 97747 | &nbsp;&nbsp; 1025430 | &nbsp;&nbsp; 57998 |
| ***Liabilities*** |  |  |  |  |
| Payable for securities purchased | 86 | &nbsp;&nbsp; 1148 | &nbsp;&nbsp; 456 | &nbsp;&nbsp; — |
| Payable for fund shares redeemed |  | &nbsp;&nbsp; 5 | &nbsp;&nbsp; 4236 | &nbsp;&nbsp; — |
| Management fee payable | 110 | &nbsp;&nbsp; 75 | &nbsp;&nbsp; 794 | &nbsp;&nbsp; 45 |
| Distribution fee payable |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 3 | &nbsp;&nbsp; — |
| Foreign capital gains tax liability | 133 | &nbsp;&nbsp; 628 | &nbsp;&nbsp; 4943 | &nbsp;&nbsp; 199 |
| Other payables and accrued expenses | 124 | &nbsp;&nbsp; 128 | &nbsp;&nbsp; 512 | &nbsp;&nbsp; 165 |
| Total liabilities | 453 | &nbsp;&nbsp; 1984 | &nbsp;&nbsp; 10944 | &nbsp;&nbsp; 409 |
| Net assets | $130252 | &nbsp;&nbsp; $95763 | &nbsp;&nbsp; $1014486 | &nbsp;&nbsp; $57589 |
| ***Capital*** |  |  |  |  |
| Composition of net assets |  |  |  |  |
| Paid in capital | $125984 | &nbsp;&nbsp; $133217 | &nbsp;&nbsp; $701012 | &nbsp;&nbsp; $43694 |
| Total distributable earnings (loss) | 4268 | &nbsp;&nbsp; (37454)<br>| &nbsp;&nbsp; 313474 | &nbsp;&nbsp; 13895 |
| Net assets | $130252 | &nbsp;&nbsp; $95763 | &nbsp;&nbsp; $1014486 | &nbsp;&nbsp; $57589 |
| Class N shares |  |  |  |  |
| Net assets | $1264 | &nbsp;&nbsp; $1082 | &nbsp;&nbsp; $14900 | &nbsp;&nbsp; — |
| Shares outstanding | 91213 | &nbsp;&nbsp; 93847 | &nbsp;&nbsp; 954197 | &nbsp;&nbsp; — |
| Net asset value per share | $13.85 | &nbsp;&nbsp; $11.53 | &nbsp;&nbsp; $15.62 | &nbsp;&nbsp; — |
| Class I shares |  |  |  |  |
| Net assets | $73624 | &nbsp;&nbsp; $9061 | &nbsp;&nbsp; $317344 | &nbsp;&nbsp; $14860 |
| Shares outstanding | 5234640 | &nbsp;&nbsp; 781948 | &nbsp;&nbsp; 19862517 | &nbsp;&nbsp; 928780 |
| Net asset value per share | $14.06 | &nbsp;&nbsp; $11.59 | &nbsp;&nbsp; $15.98 | &nbsp;&nbsp; $16.00 |
| Class R6 shares |  |  |  |  |
| Net assets | $55364 | &nbsp;&nbsp; $85620 | &nbsp;&nbsp; $682242 | &nbsp;&nbsp; $42729 |
| Shares outstanding | 3910916 | &nbsp;&nbsp; 7399960 | &nbsp;&nbsp; 42168361 | &nbsp;&nbsp; 2665600 |
| Net asset value per share | $14.16 | &nbsp;&nbsp; $11.57 | &nbsp;&nbsp; $16.18 | &nbsp;&nbsp; $16.03 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**73**

*William Blair Funds*

------

**Statements of Operations**

**For the Year Ended December 31, 2025** *(dollar amounts in thousands)*

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **International** <br>**Small Cap** <br>**Growth** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**Leaders** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**Growth** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**ex China** <br>**Growth Fund**<br>|
| ***Investment income*** |  |  |  |  |
| Dividends | $2759 | &nbsp;&nbsp; $3078 | &nbsp;&nbsp; $16283 | &nbsp;&nbsp; $782 |
| Less foreign tax withheld | (271)<br>| &nbsp;&nbsp; (359)<br>| &nbsp;&nbsp; (1868)<br>| &nbsp;&nbsp; (94)<br>|
| Interest | 38 | &nbsp;&nbsp; 21 | &nbsp;&nbsp; 99 | &nbsp;&nbsp; 7 |
| Other income | 117 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total income | 2643 | &nbsp;&nbsp; 2740 | &nbsp;&nbsp; 14514 | &nbsp;&nbsp; 695 |
| ***Expenses*** |  |  |  |  |
| Management fees | 1581 | &nbsp;&nbsp; 1336 | &nbsp;&nbsp; 8724 | &nbsp;&nbsp; 392 |
| Distribution fees | 3 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; — |
| Custodian fees | 153 | &nbsp;&nbsp; 161 | &nbsp;&nbsp; 504 | &nbsp;&nbsp; 173 |
| Transfer agent fees | 20 | &nbsp;&nbsp; 16 | &nbsp;&nbsp; 112 | &nbsp;&nbsp; 3 |
| Sub-transfer agent fees |  |  |  |  |
| Class N | 2 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 18 | &nbsp;&nbsp; — |
| Class I | 80 | &nbsp;&nbsp; 8 | &nbsp;&nbsp; 348 | &nbsp;&nbsp; 11 |
| Professional fees | 104 | &nbsp;&nbsp; 83 | &nbsp;&nbsp; 197 | &nbsp;&nbsp; 112 |
| Registration fees | 48 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 63 | &nbsp;&nbsp; 33 |
| Shareholder reporting fees | 15 | &nbsp;&nbsp; 12 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; 11 |
| Trustee fees | 15 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; 81 | &nbsp;&nbsp; 3 |
| Other expenses | 7 | &nbsp;&nbsp; 7 | &nbsp;&nbsp; 30 | &nbsp;&nbsp; 5 |
| Total expenses before expense limitation | 2028 | &nbsp;&nbsp; 1690 | &nbsp;&nbsp; 10164 | &nbsp;&nbsp; 743 |
| Expenses waived or reimbursed by the Adviser |  |  |  |  |
| Class N | (3)<br>| &nbsp;&nbsp; (3)<br>| &nbsp;&nbsp; (27)<br>| &nbsp;&nbsp; — |
| Class I | (181)<br>| &nbsp;&nbsp; (27)<br>| &nbsp;&nbsp; (513)<br>| &nbsp;&nbsp; (93)<br>|
| Class R6 | (141)<br>| &nbsp;&nbsp; (316)<br>| &nbsp;&nbsp; (723)<br>| &nbsp;&nbsp; (252)<br>|
| Total expenses waived or reimbursed by the Adviser | (325)<br>| &nbsp;&nbsp; (346)<br>| &nbsp;&nbsp; (1263)<br>| &nbsp;&nbsp; (345)<br>|
| Net expenses | 1703 | &nbsp;&nbsp; 1344 | &nbsp;&nbsp; 8901 | &nbsp;&nbsp; 398 |
| Net investment income (loss) | 940 | &nbsp;&nbsp; 1396 | &nbsp;&nbsp; 5613 | &nbsp;&nbsp; 297 |
| ***Realized and unrealized gain (loss)*** |  |  |  |  |
| Net realized gain (loss) on transactions from: |  |  |  |  |
| Investments in securities (net of foreign capital gains tax paid $294; $796; <br> $2,616; $68)<br>| 30716 | &nbsp;&nbsp; 37047 | &nbsp;&nbsp; 96952 | &nbsp;&nbsp; 3285 |
| Foreign currency transactions | (17)<br>| &nbsp;&nbsp; (194)<br>| &nbsp;&nbsp; (916)<br>| &nbsp;&nbsp; (57)<br>|
| Total net realized gain | 30699 | &nbsp;&nbsp; 36853 | &nbsp;&nbsp; 96036 | &nbsp;&nbsp; 3228 |
| Change in net unrealized appreciation (depreciation) of: |  |  |  |  |
| Investments in securities (net of foreign capital gains tax accrual $(576); <br> $(203); $(4855); $(230))<br>| (7463)<br>| &nbsp;&nbsp; (5691)<br>| &nbsp;&nbsp; 117558 | &nbsp;&nbsp; 7731 |
| Foreign currency translations | 41 | &nbsp;&nbsp; (2)<br>| &nbsp;&nbsp; (29)<br>| &nbsp;&nbsp; — |
| Change in net unrealized appreciation (depreciation) | (7422)<br>| &nbsp;&nbsp; (5693)<br>| &nbsp;&nbsp; 117529 | &nbsp;&nbsp; 7731 |
| **Net increase (decrease) in net assets resulting from operations** | $24217 | &nbsp;&nbsp; $32556 | &nbsp;&nbsp; $219178 | &nbsp;&nbsp; $11256 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**74**

*Annual*

------

**Statements of Changes in Net Assets**

**For the Years Ended December 31, 2025 and 2024** *(dollar amounts in thousands)*

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **International** <br>**Small Cap** <br>**Growth** <br>**Fund** | **International** <br>**Small Cap** <br>**Growth** <br>**Fund** | **Emerging** <br>**Markets** <br>**Leaders** <br>**Fund** | **Emerging** <br>**Markets** <br>**Leaders** <br>**Fund** | **Emerging** <br>**Markets** <br>**Growth** <br>**Fund** | **Emerging** <br>**Markets** <br>**Growth** <br>**Fund** | **Emerging** <br>**Markets** <br>**ex China** <br>**Growth Fund** | **Emerging** <br>**Markets** <br>**ex China** <br>**Growth Fund** |
|  | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** |
| ***Operations*** |  |  |  |  |  |  |  |  |
| Net investment income (loss) | $940 | &nbsp;&nbsp; $1893 | &nbsp;&nbsp; $1396 | &nbsp;&nbsp; $1705 | &nbsp;&nbsp; $5613 | &nbsp;&nbsp; $3348 | &nbsp;&nbsp; $297 | &nbsp;&nbsp; $124 |
| Net realized gain (loss) on <br> investments, and other assets and <br> liabilities<br>| 30699 | &nbsp;&nbsp; 10008 | &nbsp;&nbsp; 36853 | &nbsp;&nbsp; 27692 | &nbsp;&nbsp; 96036 | &nbsp;&nbsp; 46477 | &nbsp;&nbsp; 3228 | &nbsp;&nbsp; 869 |
| Change in net unrealized <br> appreciation (depreciation) on <br> investments, and other assets and <br> liabilities<br>| (7422)<br>| &nbsp;&nbsp; (9856)<br>| &nbsp;&nbsp; (5693)<br>| &nbsp;&nbsp; (15373)<br>| &nbsp;&nbsp; 117529 | &nbsp;&nbsp; 28651 | &nbsp;&nbsp; 7731 | &nbsp;&nbsp; 1764 |
| Net increase (decrease) in net <br> assets resulting from operations<br>| 24217 | &nbsp;&nbsp; 2045 | &nbsp;&nbsp; 32556 | &nbsp;&nbsp; 14024 | &nbsp;&nbsp; 219178 | &nbsp;&nbsp; 78476 | &nbsp;&nbsp; 11256 | &nbsp;&nbsp; 2757 |
| ***Distributions to shareholders*** |  |  |  |  |  |  |  |  |
| Class N | (5)<br>| &nbsp;&nbsp; (20)<br>| &nbsp;&nbsp; (7)<br>| &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; (19)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I | (448)<br>| &nbsp;&nbsp; (1322)<br>| &nbsp;&nbsp; (79)<br>| &nbsp;&nbsp; (27)<br>| &nbsp;&nbsp; (1265)<br>| &nbsp;&nbsp; (243)<br>| &nbsp;&nbsp; (797)<br>| &nbsp;&nbsp; — |
| Class R6 | (362)<br>| &nbsp;&nbsp; (1462)<br>| &nbsp;&nbsp; (794)<br>| &nbsp;&nbsp; (476)<br>| &nbsp;&nbsp; (3030)<br>| &nbsp;&nbsp; (825)<br>| &nbsp;&nbsp; (2223)<br>| &nbsp;&nbsp; — |
| Total distributions | (815)<br>| &nbsp;&nbsp; (2804)<br>| &nbsp;&nbsp; (880)<br>| &nbsp;&nbsp; (504)<br>| &nbsp;&nbsp; (4314)<br>| &nbsp;&nbsp; (1068)<br>| &nbsp;&nbsp; (3020)<br>| &nbsp;&nbsp; — |
| ***Capital stock transactions*** |  |  |  |  |  |  |  |  |
| Proceeds from sales of shares | 6559 | &nbsp;&nbsp; 16744 | &nbsp;&nbsp; 17506 | &nbsp;&nbsp; 17651 | &nbsp;&nbsp; 303095 | &nbsp;&nbsp; 254801 | &nbsp;&nbsp; 15475 | &nbsp;&nbsp; 14405 |
| Shares issued in reinvestment of <br> income dividends and capital <br> gain distributions<br>| 803 | &nbsp;&nbsp; 2557 | &nbsp;&nbsp; 879 | &nbsp;&nbsp; 504 | &nbsp;&nbsp; 4079 | &nbsp;&nbsp; 1009 | &nbsp;&nbsp; 2720 | &nbsp;&nbsp; — |
| Less cost of shares redeemed | (61212)<br>| &nbsp;&nbsp; (98588)<br>| &nbsp;&nbsp; (118999)<br>| &nbsp;&nbsp; (120559)<br>| &nbsp;&nbsp; (387586)<br>| &nbsp;&nbsp; (276025)<br>| &nbsp;&nbsp; (4314)<br>| &nbsp;&nbsp; (3700)<br>|
| Net increase (decrease) in net <br> assets resulting from capital <br> share transactions<br>| (53850)<br>| &nbsp;&nbsp; (79287)<br>| &nbsp;&nbsp; (100614)<br>| &nbsp;&nbsp; (102404)<br>| &nbsp;&nbsp; (80412)<br>| &nbsp;&nbsp; (20215)<br>| &nbsp;&nbsp; 13881 | &nbsp;&nbsp; 10705 |
| Net increase (decrease) in net <br> assets<br>| (30448)<br>| &nbsp;&nbsp; (80046)<br>| &nbsp;&nbsp; (68938)<br>| &nbsp;&nbsp; (88884)<br>| &nbsp;&nbsp; 134452 | &nbsp;&nbsp; 57193 | &nbsp;&nbsp; 22117 | &nbsp;&nbsp; 13462 |
| ***Net Assets*** |  |  |  |  |  |  |  |  |
| Beginning of period | 160700 | &nbsp;&nbsp; 240746 | &nbsp;&nbsp; 164701 | &nbsp;&nbsp; 253585 | &nbsp;&nbsp; 880034 | &nbsp;&nbsp; 822841 | &nbsp;&nbsp; 35472 | &nbsp;&nbsp; 22010 |
| End of period | $130252 | &nbsp;&nbsp; $160700 | &nbsp;&nbsp; $95763 | &nbsp;&nbsp; $164701 | &nbsp;&nbsp; $1014486 | &nbsp;&nbsp; $880034 | &nbsp;&nbsp; $57589 | &nbsp;&nbsp; $35472 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**75**

*William Blair Funds*

------

**Statements of Assets and Liabilities**

**As of December 31, 2025** *(dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | **Emerging** <br>**Markets** <br>**Small Cap** <br>**Growth Fund**<br>| **China** <br>**Growth** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**Debt** <br>**Fund**<br>|
| ***Assets*** |  |  |  |
| Investments in securities, at cost | $302677 | &nbsp;&nbsp; $1525 | &nbsp;&nbsp; $66231 |
| Investments in securities, at value | $361967 | &nbsp;&nbsp; $2048 | &nbsp;&nbsp; $70580 |
| Cash |  | &nbsp;&nbsp; 74 | &nbsp;&nbsp; 30 |
| Foreign currency, at value (cost $927;—;—) | 927 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Receivable for securities sold | 7484 | &nbsp;&nbsp; — | &nbsp;&nbsp; 142 |
| Receivable for fund shares sold | 159 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1262 |
| Receivable from Adviser | 62 | &nbsp;&nbsp; 13 | &nbsp;&nbsp; 28 |
| Dividends and interest receivable | 1145 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 1300 |
| Unrealized appreciation on forward foreign currency contracts |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 5 |
| Total assets | 371744 | &nbsp;&nbsp; 2138 | &nbsp;&nbsp; 73347 |
| ***Liabilities*** |  |  |  |
| Payable for variation margin on centrally cleared swaps |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 27 |
| Unrealized depreciation on forward foreign currency contracts |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 56 |
| Payable for securities purchased | 2923 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Payable for fund shares redeemed | 254 | &nbsp;&nbsp; — | &nbsp;&nbsp; 33 |
| Management fee payable | 346 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 39 |
| Distribution fee payable | 1 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Foreign capital gains tax liability | 140 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Distributions payable to shareholders |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 95 |
| Other payables and accrued expenses | 297 | &nbsp;&nbsp; 58 | &nbsp;&nbsp; 99 |
| Total liabilities | 3961 | &nbsp;&nbsp; 60 | &nbsp;&nbsp; 349 |
| Net assets | $367783 | &nbsp;&nbsp; $2078 | &nbsp;&nbsp; $72998 |
| ***Capital*** |  |  |  |
| Composition of net assets |  |  |  |
| Paid in capital | $302082 | &nbsp;&nbsp; $4593 | &nbsp;&nbsp; $77738 |
| Total distributable earnings (loss) | 65701 | &nbsp;&nbsp; (2515)<br>| &nbsp;&nbsp; (4740)<br>|
| Net assets | $367783 | &nbsp;&nbsp; $2078 | &nbsp;&nbsp; $72998 |
| Class N shares |  |  |  |
| Net assets | $3705 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Shares outstanding | 168518 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net asset value per share | $21.99 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I shares |  |  |  |
| Net assets | $135573 | &nbsp;&nbsp; $89 | &nbsp;&nbsp; $40984 |
| Shares outstanding | 6046423 | &nbsp;&nbsp; 13607 | &nbsp;&nbsp; 4677618 |
| Net asset value per share | $22.42 | &nbsp;&nbsp; $6.53 | &nbsp;&nbsp; $8.76 |
| Class R6 shares |  |  |  |
| Net assets | $228505 | &nbsp;&nbsp; $1989 | &nbsp;&nbsp; $32014 |
| Shares outstanding | 10155307 | &nbsp;&nbsp; 306096 | &nbsp;&nbsp; 3658241 |
| Net asset value per share | $22.50 | &nbsp;&nbsp; $6.50 | &nbsp;&nbsp; $8.75 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**76**

*Annual*

------

**Statements of Operations**

**For the Year Ended December 31, 2025** *(dollar amounts in thousands)*

---

| | | | |
|:---|:---|:---|:---|
|  | **Emerging** <br>**Markets** <br>**Small Cap** <br>**Growth Fund**<br>| **China** <br>**Growth** <br>**Fund**<br>| **Emerging** <br>**Markets** <br>**Debt** <br>**Fund**<br>|
| ***Investment income*** |  |  |  |
| Dividends | $10500 | &nbsp;&nbsp; $36 | &nbsp;&nbsp; $— |
| Less foreign tax withheld | (800)<br>| &nbsp;&nbsp; (3)<br>| &nbsp;&nbsp; — |
| Interest | 45 | &nbsp;&nbsp; — | &nbsp;&nbsp; 4173 |
| Less foreign tax withheld |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (14)<br>|
| Total income | 9745 | &nbsp;&nbsp; 33 | &nbsp;&nbsp; 4159 |
| ***Expenses*** |  |  |  |
| Management fees | 3976 | &nbsp;&nbsp; 19 | &nbsp;&nbsp; 373 |
| Distribution fees | 9 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Custodian fees | 435 | &nbsp;&nbsp; 67 | &nbsp;&nbsp; 125 |
| Transfer agent fees | 46 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 5 |
| Sub-transfer agent fees |  |  |  |
| Class N | 5 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I | 145 | &nbsp;&nbsp; — | &nbsp;&nbsp; 33 |
| Professional fees | 195 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; 46 |
| Registration fees | 49 | &nbsp;&nbsp; 34 | &nbsp;&nbsp; 41 |
| Shareholder reporting fees | 30 | &nbsp;&nbsp; 8 | &nbsp;&nbsp; 13 |
| Trustee fees | 35 | &nbsp;&nbsp; — | &nbsp;&nbsp; 5 |
| Other expenses | 15 | &nbsp;&nbsp; 4 | &nbsp;&nbsp; 10 |
| Total expenses before expense limitation | 4940 | &nbsp;&nbsp; 169 | &nbsp;&nbsp; 651 |
| Expenses waived or reimbursed by the Adviser |  |  |  |
| Class N | (11)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I | (380)<br>| &nbsp;&nbsp; (6)<br>| &nbsp;&nbsp; (136)<br>|
| Class R6 | (496)<br>| &nbsp;&nbsp; (144)<br>| &nbsp;&nbsp; (123)<br>|
| Total expenses waived or reimbursed by the Adviser | (887)<br>| &nbsp;&nbsp; (150)<br>| &nbsp;&nbsp; (259)<br>|
| Net expenses | 4053 | &nbsp;&nbsp; 19 | &nbsp;&nbsp; 392 |
| Net investment income (loss) | 5692 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; 3767 |
| ***Realized and unrealized gain (loss)*** |  |  |  |
| Net realized gain (loss) on transactions from: |  |  |  |
| Investments in securities (net of foreign capital gains tax paid $116; $—; $3) | 36785 | &nbsp;&nbsp; 95 | &nbsp;&nbsp; 651 |
| Written options |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 30 |
| Swaps |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (282)<br>|
| Forward foreign currency contracts |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (173)<br>|
| Foreign currency transactions | (1743)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (13)<br>|
| Total net realized gain | 35042 | &nbsp;&nbsp; 95 | &nbsp;&nbsp; 213 |
| Change in net unrealized appreciation (depreciation) of: |  |  |  |
| Investments in securities (net of foreign capital gains tax accrual $(6280); $—; $—) | 1282 | &nbsp;&nbsp; 317 | &nbsp;&nbsp; 4686 |
| Swaps |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 418 |
| Forward foreign currency transactions |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (111)<br>|
| Foreign currency translations | (35)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 16 |
| Change in net unrealized appreciation | 1247 | &nbsp;&nbsp; 317 | &nbsp;&nbsp; 5009 |
| **Net increase (decrease) in net assets resulting from operations** | $41981 | &nbsp;&nbsp; $426 | &nbsp;&nbsp; $8989 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**77**

*William Blair Funds*

------

**Statements of Changes in Net Assets**

**For the Years Ended December 31, 2025 and 2024** *(dollar amounts in thousands)*

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Emerging** <br>**Markets** <br>**Small Cap** <br>**Growth Fund** | **Emerging** <br>**Markets** <br>**Small Cap** <br>**Growth Fund** | **China** <br>**Growth** <br>**Fund** | **China** <br>**Growth** <br>**Fund** | **Emerging** <br>**Markets** <br>**Debt** <br>**Fund** | **Emerging** <br>**Markets** <br>**Debt** <br>**Fund** |
|  | **2025** | **2024** | **2025** | **2024** | **2025** | **2024** |
| ***Operations*** |  |  |  |  |  |  |
| Net investment income (loss) | $5692 | &nbsp;&nbsp; $2106 | &nbsp;&nbsp; $14 | &nbsp;&nbsp; $23 | &nbsp;&nbsp; $3767 | &nbsp;&nbsp; $4186 |
| Net realized gain (loss) on investments, and other assets and <br> liabilities<br>| 35042 | &nbsp;&nbsp; 55831 | &nbsp;&nbsp; 95 | &nbsp;&nbsp; (273)<br>| &nbsp;&nbsp; 213 | &nbsp;&nbsp; 910 |
| Change in net unrealized appreciation (depreciation) on <br> investments, and other assets and liabilities<br>| 1247 | &nbsp;&nbsp; (25571)<br>| &nbsp;&nbsp; 317 | &nbsp;&nbsp; 429 | &nbsp;&nbsp; 5009 | &nbsp;&nbsp; (265)<br>|
| Net increase (decrease) in net assets resulting from operations | 41981 | &nbsp;&nbsp; 32366 | &nbsp;&nbsp; 426 | &nbsp;&nbsp; 179 | &nbsp;&nbsp; 8989 | &nbsp;&nbsp; 4831 |
| ***Distributions to shareholders*** |  |  |  |  |  |  |
| Class N | (331)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Class I | (12059)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; (1843 )<sup>(a)</sup><br>| &nbsp;&nbsp; (341)<br>|
| Class R6 | (20843)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (18)<br>| &nbsp;&nbsp; (24)<br>| &nbsp;&nbsp; (1950 )<sup>(a)</sup><br>| &nbsp;&nbsp; (3500)<br>|
| Total distributions | (33233)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (19)<br>| &nbsp;&nbsp; (25)<br>| &nbsp;&nbsp; (3793)<br>| &nbsp;&nbsp; (3841)<br>|
| ***Capital stock transactions*** |  |  |  |  |  |  |
| Proceeds from sales of shares | 42110 | &nbsp;&nbsp; 73248 | &nbsp;&nbsp; 41 | &nbsp;&nbsp; 230 | &nbsp;&nbsp; 38614 | &nbsp;&nbsp; 19638 |
| Shares issued in reinvestment of income dividends and capital gain <br> distributions<br>| 32793 | &nbsp;&nbsp; — | &nbsp;&nbsp; 18 | &nbsp;&nbsp; 25 | &nbsp;&nbsp; 2960 | &nbsp;&nbsp; 3839 |
| Less cost of shares redeemed | (113961)<br>| &nbsp;&nbsp; (97233)<br>| &nbsp;&nbsp; (116)<br>| &nbsp;&nbsp; (528)<br>| &nbsp;&nbsp; (39863)<br>| &nbsp;&nbsp; (11812)<br>|
| Net increase (decrease) in net assets resulting from capital share <br> transactions<br>| (39058)<br>| &nbsp;&nbsp; (23985)<br>| &nbsp;&nbsp; (57)<br>| &nbsp;&nbsp; (273)<br>| &nbsp;&nbsp; 1711 | &nbsp;&nbsp; 11665 |
| Net increase (decrease) in net assets | (30310)<br>| &nbsp;&nbsp; 8381 | &nbsp;&nbsp; 350 | &nbsp;&nbsp; (119)<br>| &nbsp;&nbsp; 6907 | &nbsp;&nbsp; 12655 |
| ***Net Assets*** |  |  |  |  |  |  |
| Beginning of period | 398093 | &nbsp;&nbsp; 389712 | &nbsp;&nbsp; 1728 | &nbsp;&nbsp; 1847 | &nbsp;&nbsp; 66091 | &nbsp;&nbsp; 53436 |
| End of period | $367783 | &nbsp;&nbsp; $398093 | &nbsp;&nbsp; $2078 | &nbsp;&nbsp; $1728 | &nbsp;&nbsp; $72998 | &nbsp;&nbsp; $66091 |

---

------

&nbsp;&nbsp;&nbsp;&nbsp;(a) Included in the distribution is a tax return of capital in the amount of $68 and $73
 (in thousands) for Class I and Class R6, respectively.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**78**

*Annual*

------

**Notes to Financial Statements** 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**(1)** **Organization** 

*(a)* *Description of the Trust*

William Blair Funds (the "Trust") is a Delaware statutory trust registered under the Investment Company Act of 1940, as amended (the "1940 Act"), as an open-end management investment company. As of the date of this report, the Trust has the following nineteen funds (the "Funds") available for sale, each with its own investment objective and policies. For each Fund, the number of shares authorized is unlimited.

**<u>U.S. Equity</u>**

Growth Fund

Large Cap Growth Fund

Mid Cap Value Fund

Small-Mid Cap Core Fund

Small-Mid Cap Growth Fund

Small-Mid Cap Value Fund

Small Cap Growth Fund

Small Cap Value Fund

**<u>Global Equity</u>**

Global Leaders Fund

**<u>International Equity</u>**

International Leaders Fund

International Growth Fund

Institutional International Growth Fund

International Small Cap Growth Fund

Emerging Markets Leaders Fund

Emerging Markets Growth Fund

Emerging Markets ex China Growth Fund

Emerging Markets Small Cap Growth Fund

China Growth Fund

**<u>Emerging Markets Debt</u>**

Emerging Markets Debt Fund

William Blair Investment Management, LLC (the "Adviser") serves as the Trust's investment adviser. William Blair & Company, L.L.C. ("WBC" or the "Distributor"), an affiliate of the Adviser, serves as the Trust's principal underwriter and distributor. The Adviser and WBC are referred to herein collectively as "William Blair."

*(b)* *Share Classes*

Each Fund is comprised of Class N, Class I and Class R6 shares, except the Mid Cap Value, Small-Mid Cap Core, Small-Mid Cap Value, Emerging Markets ex China Growth, China Growth and Emerging Markets Debt Funds, which are comprised of Class I and Class R6 shares. Institutional International Growth Fund does not offer multiple classes of shares.

**Class N** shares are available to the general public, either directly through the Trust's distributor or through a select number of financial intermediaries. Class N shares are sold without any sales load and carry an annual 12b-1 distribution fee at a fixed rate (0.25% for all Funds as discussed in *Note 4(b) – Transactions with Affiliates – Underwriting and Distribution Services Agreements*) and a sub-transfer agent fee that is not a fixed rate and varies by Fund and class, as discussed below.

**Class I** shares are available to certain retirement and deferred compensation plans, clients of certain financial intermediaries, and asset-based fee advisory clients of William Blair. The minimum initial investment for a Class I account is $500,000, subject to certain exceptions. Class I shares do not carry any sales load or distribution fees and generally have lower ongoing expenses than Class N shares. Class I shares have a sub-transfer agent fee that is not a fixed rate and varies by Fund and class, as discussed below.

**Class R6** shares are available to certain retirement and deferred compensation plans, clients of certain financial intermediaries, asset-based fee advisory clients of William Blair, and additional types of investors, provided that neither the investor nor the financial intermediary requires the Funds to make any type of servicing or administrative payment. The minimum initial investment for a Class R6 account is $1 million, subject to certain exceptions.

**Institutional** shares are available only to investors of Institutional International Growth Fund and comprise all of the outstanding shares of this Fund. Institutional shares require a minimum initial investment of $5 million, subject to certain exceptions.

Class R6 shares and Institutional shares of the Institutional International Growth Fund do not carry any sales load, distribution fees or sub-transfer agent fees. Class R6 shares of a Fund generally have lower ongoing expenses than the Fund's Class N and Class I shares.

*Sub-transfer agent fees*: For Class N and Class I shares, the Funds may reimburse WBC for fees paid to intermediaries such as banks, broker-dealers, financial advisers or other financial institutions for sub-administration, sub-transfer agency and other services provided to investors whose shares of record are held in omnibus, other group accounts, retirement plans or accounts traded through registered securities clearing agents. These fees may vary based on, for example, the nature of services

*December 31, 2025*

**79**

*William Blair Funds*

------

**Notes to Financial Statements** 

provided, but generally range up to 0.15% of the assets of the class serviced or maintained by the intermediary or up to $15 per sub-account maintained by the intermediary, depending on the method by which the intermediary charges for the services.

*(c)* *Fund Objectives*

The investment objectives of the Funds are as follows:

---

| | |
|:---|:---|
| U.S. Equity Funds | Long-term capital appreciation. |
| Global Equity Fund | Long-term capital appreciation. |
| International Equity Funds | Long-term capital appreciation. |
| Emerging Markets Debt Fund | Provide attractive risk-adjusted returns relative to the Fund's benchmark. |

---

**(2)** **Significant Accounting Policies**

The following is a summary of the Trust's significant accounting policies in effect during the periods covered by the financial statements, which are in accordance with U.S. generally accepted accounting principles ("US GAAP"), which includes the accounting and reporting guidelines under Accounting Standards Topic 946, *Financial Services—Investment Companies*.

Each Fund represents a single operating segment and therefore, a single reportable segment. The Adviser serves as the chief operating decision maker.

*(a)* *Investment income and transactions*

Investment income, realized and unrealized gains and losses, and certain Fund level expenses and expense reductions, if any, are allocated based on the relative net assets of each class, except for certain class-specific expenses, which are charged directly to the appropriate class. Differences in class expenses may result in the payment of different per share dividends by class. All share classes of the Funds have equal rights with respect to voting, subject to class specific arrangements.

Dividend income and expenses are recorded on the ex-dividend date, except for those dividends from certain foreign securities that are recorded when the information is available.

Interest income is recorded on an accrual basis, adjusted for amortization of premium or accretion of discount. Variable rate bonds and floating rate notes earn interest at coupon rates that fluctuate at specific time intervals. The interest rates shown in the Portfolio of Investments for the Emerging Markets Debt Fund were the rates in effect on December 31, 2025. Put bonds may be redeemed at the discretion of the holder on specified dates prior to maturity.

Premiums and discounts are amortized and accreted, respectively, on a straight-line basis for short-term investments and on an effective interest method for long-term investments.

The Funds do not isolate the portion of operations resulting from fluctuations in foreign currency exchange rates on investments from the fluctuations arising from changes in the value of securities held. Such currency fluctuations are included with the net realized and unrealized gain or loss from investments.

Reported net realized foreign currency gains or losses arise from disposition of foreign currency, the difference in the foreign exchange rates between the trade and settlement dates on securities transactions, and the difference between the amounts of dividends, interest and foreign withholding taxes recorded on the ex-date or accrual date and the U.S. dollar equivalent of the amounts actually received or paid. Net unrealized foreign exchange gains and losses arise from changes (due to the changes in the exchange rate) in the value of foreign currency and other assets and liabilities denominated in foreign currencies held at period end.

For financial reporting purposes, security and shareholder transactions are recorded on trade date in accordance with US GAAP. Realized gains and losses from securities transactions are recognized on a specifically identified cost basis.

Awards from class action litigation may be recorded as a reduction of cost. If the Funds no longer own the applicable securities, the proceeds are recorded as realized gains.

For the year ended December 31, 2025, the International Leaders Fund, International Growth Fund, Institutional International Growth Fund, and International Small Cap Growth Fund received tax reclaim payments from certain member countries of the European Union, including interest, of $568, $170, $115, and $117, respectively (in thousands), relating to amounts withheld on dividends received by the Funds during the fiscal years ended December 31, 2018 through 2022. The amounts withheld on

*December 31, 2025*

**80**

*Annual*

------

**Notes to Financial Statements** 

dividends were not previously passed through to the Funds' shareholders in the years the dividends were received by the Funds. The payments received are included within Other Income in the Statement of Operations.

*(b)* *Share Valuation and Distributions to Shareholders*

Shares are sold and redeemed on a continuous basis at net asset value. The net asset value per share is determined separately for each class by dividing the Fund's net assets attributable to that class by the number of shares of the class outstanding as of the close of regular trading on the New York Stock Exchange (the "NYSE"), which is generally 4:00 p.m. Eastern time, on each day the NYSE is open.

Distributions from net investment income, if any, for all Equity Funds are declared and paid at least annually. Distributions from net investment income for Emerging Markets Debt Fund are declared daily and paid monthly. Capital gain distributions, if any, for all Funds, are declared and paid at least annually in December and/or January. Distributions payable to shareholders are recorded on the ex-dividend date.

*(c)* *Foreign Currency Translation*

The Funds may invest in securities denominated in foreign currencies. As such, assets and liabilities denominated in foreign currencies are translated into U.S. dollar amounts at the current exchange rate on the date of valuation. The values of foreign investments, open forward foreign currency contracts, and cash denominated in foreign currencies are translated into U.S. dollars using a spot market rate of exchange as of the time of the determination of each Fund's net asset value, typically 4:00 p.m. Eastern time on days when there is regular trading on the NYSE. Receivables and payables for securities transactions, dividends, interest income and tax reclaims are translated into U.S. dollars using a spot market rate of exchange as of 4:00 p.m. Eastern time. Settlement of purchases and sales and dividend and interest receipts are translated into U.S. dollars using a spot market rate of exchange as of 11:00 a.m. Eastern time.

*(d)* *Income Taxes*

Each Fund intends to comply with the provisions of Subchapter M of the Code, in order to qualify as regulated investment companies. Each Fund intends to make the requisite distributions of income and capital gains to its shareholders sufficient to relieve it from all, or substantially all, federal income and excise taxes. No provision for federal income and excise taxes has been made.

Certain Funds may be subject to foreign income taxes imposed on realized gains on securities of issuers from certain foreign countries. Such taxes, if applicable, are accrued and included within change in net unrealized appreciation (depreciation) and net realized gain (loss) on transactions from investments in securities in the Statement of Operations.

Management evaluates tax positions taken or expected to be taken in the course of preparing the Funds' tax returns to determine whether it is "more likely than not" that each tax position would be sustained upon examination by a taxing authority based on the technical merits of the positions. Tax positions not deemed to meet the "more likely than not" threshold would be recorded as a tax benefit or expense in the current year. Management has evaluated all of the uncertain tax positions of the Funds and has determined that no liability is required to be recorded in the financial statements.

The statute of limitations on the Funds' U.S. federal and state tax returns for the prior three years remains open and the returns are subject to examination.

*December 31, 2025*

**81**

*William Blair Funds*

------

**Notes to Financial Statements** 

Adjustments to the cost of investments for tax purposes may be due to the deferred loss associated with current and prior year wash sales, income recognition from investments in real estate investment trusts, and the Funds' election to mark-to-market their investments in Passive Foreign Investment Companies ("PFICs"). The cost of investments, including derivatives, for federal income tax purposes and related gross unrealized appreciation (depreciation) and net unrealized appreciation/(depreciation) at December 31, 2025, were as follows (in thousands):

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fund** | **Cost of** <br>**Investments**<br>| **Gross** <br>**Unrealized** <br>**Appreciation**<br>| **Gross** <br>**Unrealized** <br>**Depreciation**<br>| **Net** <br>**Unrealized** <br>**Appreciation/** <br>**(Depreciation)**<br>|
| Growth Fund | $163574 | &nbsp;&nbsp; $72048 | &nbsp;&nbsp; $7201 | &nbsp;&nbsp; $64847 |
| Large Cap Growth Fund | 1879115 | &nbsp;&nbsp; 821599 | &nbsp;&nbsp; 69920 | &nbsp;&nbsp; 751679 |
| Mid Cap Value Fund | 1065 | &nbsp;&nbsp; 285 | &nbsp;&nbsp; 40 | &nbsp;&nbsp; 245 |
| Small-Mid Cap Core Fund | 113420 | &nbsp;&nbsp; 18922 | &nbsp;&nbsp; 9374 | &nbsp;&nbsp; 9548 |
| Small-Mid Cap Growth Fund | 1069756 | &nbsp;&nbsp; 267940 | &nbsp;&nbsp; 102667 | &nbsp;&nbsp; 165273 |
| Small-Mid Cap Value Fund | 3191 | &nbsp;&nbsp; 482 | &nbsp;&nbsp; 179 | &nbsp;&nbsp; 303 |
| Small Cap Growth Fund | 888752 | &nbsp;&nbsp; 168606 | &nbsp;&nbsp; 69951 | &nbsp;&nbsp; 98655 |
| Small Cap Value Fund | 787548 | &nbsp;&nbsp; 169555 | &nbsp;&nbsp; 37648 | &nbsp;&nbsp; 131907 |
| Global Leaders Fund | 15125 | &nbsp;&nbsp; 3188 | &nbsp;&nbsp; 443 | &nbsp;&nbsp; 2745 |
| International Leaders Fund | 857569 | &nbsp;&nbsp; 263176 | &nbsp;&nbsp; 9967 | &nbsp;&nbsp; 253209 |
| International Growth Fund | 854480 | &nbsp;&nbsp; 293138 | &nbsp;&nbsp; 22608 | &nbsp;&nbsp; 270530 |
| Institutional International Growth Fund | 636964 | &nbsp;&nbsp; 213821 | &nbsp;&nbsp; 16665 | &nbsp;&nbsp; 197156 |
| International Small Cap Growth Fund | 105375 | &nbsp;&nbsp; 29188 | &nbsp;&nbsp; 4515 | &nbsp;&nbsp; 24673 |
| Emerging Markets Leaders Fund | 75595 | &nbsp;&nbsp; 23478 | &nbsp;&nbsp; 2820 | &nbsp;&nbsp; 20658 |
| Emerging Markets Growth Fund | 723094 | &nbsp;&nbsp; 316595 | &nbsp;&nbsp; 20019 | &nbsp;&nbsp; 296576 |
| Emerging Markets ex China Growth Fund | 43880 | &nbsp;&nbsp; 14243 | &nbsp;&nbsp; 897 | &nbsp;&nbsp; 13346 |
| Emerging Markets Small Cap Growth Fund | 305286 | &nbsp;&nbsp; 63051 | &nbsp;&nbsp; 6370 | &nbsp;&nbsp; 56681 |
| China Growth Fund | 1550 | &nbsp;&nbsp; 558 | &nbsp;&nbsp; 60 | &nbsp;&nbsp; 498 |
| Emerging Markets Debt Fund | 66258 | &nbsp;&nbsp; 4962 | &nbsp;&nbsp; 640 | &nbsp;&nbsp; 4322 |

---

In addition, the Funds may periodically record reclassifications among certain capital accounts to reflect differences between financial reporting and income tax basis distributions. The reclassifications were reported in order to reflect the tax treatment for certain permanent differences that exist between income tax regulations and US GAAP. The reclassifications generally relate to the tax treatment of net operating losses and utilization of earnings and profits distributed to shareholders on redemption of shares. These reclassifications have no impact on the net asset values or the net assets of the Funds. Accordingly, at December 31, 2025, the following reclassifications were recorded (in thousands):

---

| | | |
|:---|:---|:---|
| **Fund** | **Paid in** <br>**Capital**<br>| **Total** <br>**Distributable** <br>**Earnings** <br>**(Loss)**<br>|
| Growth Fund | $4892 | &nbsp;&nbsp; $(4892)<br>|
| Large Cap Growth Fund | 36282 | &nbsp;&nbsp; (36282)<br>|
| Mid Cap Value Fund |  | &nbsp;&nbsp; — |
| Small-Mid Cap Core Fund | 638 | &nbsp;&nbsp; (638)<br>|
| Small-Mid Cap Growth Fund | (2409)<br>| &nbsp;&nbsp; 2409 |
| Small-Mid Cap Value Fund | 1 | &nbsp;&nbsp; (1)<br>|
| Small Cap Growth Fund | 8033 | &nbsp;&nbsp; (8033)<br>|
| Small Cap Value Fund | 8 | &nbsp;&nbsp; (8)<br>|
| Global Leaders Fund | 8300 | &nbsp;&nbsp; (8300)<br>|
| International Leaders Fund | 7072 | &nbsp;&nbsp; (7072)<br>|
| International Growth Fund | 33623 | &nbsp;&nbsp; (33623)<br>|
| Institutional International Growth Fund | 8918 | &nbsp;&nbsp; (8918)<br>|
| International Small Cap Growth Fund | 1 | &nbsp;&nbsp; (1)<br>|
| Emerging Markets Leaders Fund | (1)<br>| &nbsp;&nbsp; 1 |
| Emerging Markets Growth Fund | 347 | &nbsp;&nbsp; (347)<br>|
| Emerging Markets ex China Growth Fund | 109 | &nbsp;&nbsp; (109)<br>|
| Emerging Markets Small Cap Growth Fund | 659 | &nbsp;&nbsp; (659)<br>|
| China Growth Fund | 1 | &nbsp;&nbsp; (1)<br>|
| Emerging Markets Debt Fund | (148)<br>| &nbsp;&nbsp; 148 |

---

*December 31, 2025*

**82**

*Annual*

------

**Notes to Financial Statements** 

The timing and characterization of certain income and capital gain distributions are determined annually in accordance with federal income tax regulations that may differ from US GAAP. As a result, net investment income or loss and net realized gain or loss for a reporting period may differ from the amount distributed during such period.

Distributions from net realized gains for book purposes may include short-term capital gains, which are included as ordinary income for tax purposes. The tax character of distributions paid during 2025 and 2024 was as follows (in thousands):

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Distributions Paid in 2025** | **Distributions Paid in 2025** | **Distributions Paid in 2025** | **Distributions Paid in 2025** | **Distributions Paid in 2025** | **Distributions Paid in 2025** | **Distributions Paid in 2025** | **Distributions Paid in 2025** |
|  | **Ordinary** <br>**Income** | **Ordinary** <br>**Income** | **Ordinary** <br>**Income** | **Ordinary** <br>**Income** | **Long-Term** <br>**Capital Gains** | **Long-Term** <br>**Capital Gains** | **Long-Term** <br>**Capital Gains** | **Long-Term** <br>**Capital Gains** |
| **Fund** | **Class N** | **Class I** | **Class R6** | **Institutional** <br>**Class**<br>| **Class N** | **Class I** | **Class R6** | **Institutional** <br>**Class**<br>|
| Growth Fund | $77 | &nbsp;&nbsp; $310 | &nbsp;&nbsp; $72 | &nbsp;&nbsp; $N/A | &nbsp;&nbsp; $8794 | &nbsp;&nbsp; $35345 | &nbsp;&nbsp; $8275 | &nbsp;&nbsp; $N/A |
| Large Cap Growth Fund |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 11487 | &nbsp;&nbsp; 151139 | &nbsp;&nbsp; 48128 | &nbsp;&nbsp; N/A |
| Mid Cap Value Fund | N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; 16 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; 4 | &nbsp;&nbsp; N/A |
| Small-Mid Cap Core Fund | N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 1279 | &nbsp;&nbsp; 2352 | &nbsp;&nbsp; N/A |
| Small-Mid Cap Growth Fund | 615 | &nbsp;&nbsp; 6956 | &nbsp;&nbsp; 3665 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 1308 | &nbsp;&nbsp; 14783 | &nbsp;&nbsp; 7788 | &nbsp;&nbsp; N/A |
| Small-Mid Cap Value Fund | N/A | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 31 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 20 | &nbsp;&nbsp; N/A |
| Small Cap Growth Fund | 2461 | &nbsp;&nbsp; 9954 | &nbsp;&nbsp; 5959 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 7201 | &nbsp;&nbsp; 29131 | &nbsp;&nbsp; 17440 | &nbsp;&nbsp; N/A |
| Small Cap Value Fund | 15 | &nbsp;&nbsp; 5544 | &nbsp;&nbsp; 4105 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 24 | &nbsp;&nbsp; 6727 | &nbsp;&nbsp; 4537 | &nbsp;&nbsp; N/A |
| Global Leaders Fund | 25 | &nbsp;&nbsp; 185 | &nbsp;&nbsp; 33 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 1230 | &nbsp;&nbsp; 7491 | &nbsp;&nbsp; 1198 | &nbsp;&nbsp; N/A |
| International Leaders Fund | 237 | &nbsp;&nbsp; 8145 | &nbsp;&nbsp; 5976 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 1540 | &nbsp;&nbsp; 40875 | &nbsp;&nbsp; 28912 | &nbsp;&nbsp; N/A |
| International Growth Fund | 2758 | &nbsp;&nbsp; 11072 | &nbsp;&nbsp; 1295 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 37468 | &nbsp;&nbsp; 123275 | &nbsp;&nbsp; 13845 | &nbsp;&nbsp; N/A |
| Institutional International Growth <br> Fund<br>| N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 11902 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 91589 |
| International Small Cap Growth <br> Fund<br>| 5 | &nbsp;&nbsp; 448 | &nbsp;&nbsp; 362 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets Leaders Fund | 7 | &nbsp;&nbsp; 79 | &nbsp;&nbsp; 794 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets Growth Fund | 19 | &nbsp;&nbsp; 1265 | &nbsp;&nbsp; 3030 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets ex China Growth <br> Fund<br>| N/A | &nbsp;&nbsp; 73 | &nbsp;&nbsp; 216 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 724 | &nbsp;&nbsp; 2007 | &nbsp;&nbsp; N/A |
| Emerging Markets Small Cap <br> Growth Fund<br>| 30 | &nbsp;&nbsp; 1395 | &nbsp;&nbsp; 2513 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 301 | &nbsp;&nbsp; 10664 | &nbsp;&nbsp; 18330 | &nbsp;&nbsp; N/A |
| China Growth Fund | N/A | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 18 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets Debt Fund<sup>(a)</sup> | N/A | &nbsp;&nbsp; 1843 | &nbsp;&nbsp; 1950 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |

---

------

&nbsp;&nbsp;&nbsp;&nbsp;(a) Included in the distribution is a tax return of capital in the amount of $68 and $73
 (in thousands) for Class I and Class R6, respectively.

*December 31, 2025*

**83**

*William Blair Funds*

------

**Notes to Financial Statements** 

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Distributions Paid in 2024** | **Distributions Paid in 2024** | **Distributions Paid in 2024** | **Distributions Paid in 2024** | **Distributions Paid in 2024** | **Distributions Paid in 2024** | **Distributions Paid in 2024** | **Distributions Paid in 2024** |
|  | **Ordinary** <br>**Income** | **Ordinary** <br>**Income** | **Ordinary** <br>**Income** | **Ordinary** <br>**Income** | **Long-Term** <br>**Capital Gains** | **Long-Term** <br>**Capital Gains** | **Long-Term** <br>**Capital Gains** | **Long-Term** <br>**Capital Gains** |
| **Fund** | **Class N** | **Class I** | **Class R6** | **Institutional** <br>**Class**<br>| **Class N** | **Class I** | **Class R6** | **Institutional** <br>**Class**<br>|
| Growth Fund | $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $N/A | &nbsp;&nbsp; $8100 | &nbsp;&nbsp; $34685 | &nbsp;&nbsp; $9050 | &nbsp;&nbsp; $N/A |
| Large Cap Growth Fund |  | &nbsp;&nbsp; 1226 | &nbsp;&nbsp; 633 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 10648 | &nbsp;&nbsp; 113536 | &nbsp;&nbsp; 34458 | &nbsp;&nbsp; N/A |
| Mid Cap Value Fund | N/A | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 21 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Small-Mid Cap Core Fund | N/A | &nbsp;&nbsp; 91 | &nbsp;&nbsp; 105 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 1282 | &nbsp;&nbsp; 938 | &nbsp;&nbsp; N/A |
| Small-Mid Cap Growth Fund | 1777 | &nbsp;&nbsp; 21719 | &nbsp;&nbsp; 9733 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 9611 | &nbsp;&nbsp; 117448 | &nbsp;&nbsp; 52630 | &nbsp;&nbsp; N/A |
| Small-Mid Cap Value Fund | N/A | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 59 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Small Cap Growth Fund | 3926 | &nbsp;&nbsp; 12571 | &nbsp;&nbsp; 6305 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 11346 | &nbsp;&nbsp; 36332 | &nbsp;&nbsp; 18224 | &nbsp;&nbsp; N/A |
| Small Cap Value Fund | 34 | &nbsp;&nbsp; 13640 | &nbsp;&nbsp; 11844 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 14380 | &nbsp;&nbsp; 11783 | &nbsp;&nbsp; N/A |
| Global Leaders Fund | 61 | &nbsp;&nbsp; 821 | &nbsp;&nbsp; 237 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 1378 | &nbsp;&nbsp; 15988 | &nbsp;&nbsp; 4418 | &nbsp;&nbsp; N/A |
| International Leaders Fund | 75 | &nbsp;&nbsp; 3154 | &nbsp;&nbsp; 3581 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| International Growth Fund | 3414 | &nbsp;&nbsp; 15146 | &nbsp;&nbsp; 1981 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 15051 | &nbsp;&nbsp; 54966 | &nbsp;&nbsp; 6950 | &nbsp;&nbsp; N/A |
| Institutional International Growth <br> Fund<br>| N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 12274 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 50269 |
| International Small Cap Growth <br> Fund<br>| 20 | &nbsp;&nbsp; 1322 | &nbsp;&nbsp; 1462 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets Leaders Fund | 1 | &nbsp;&nbsp; 27 | &nbsp;&nbsp; 476 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets Growth Fund |  | &nbsp;&nbsp; 243 | &nbsp;&nbsp; 825 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets ex China Growth <br> Fund<br>| N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets Small Cap <br> Growth Fund<br>|  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| China Growth Fund | N/A | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 24 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |
| Emerging Markets Debt Fund | N/A | &nbsp;&nbsp; 342 | &nbsp;&nbsp; 3499 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; N/A |

---

As of December 31, 2025, the components of distributable earnings on a tax basis were as follows (in thousands):

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **Fund** | **Undistributed** <br>**Ordinary** <br>**Income**<br>| **Accumulated** <br>**Capital and** <br>**Other Losses**<br>| **Undistributed** <br>**Long-Term** <br>**Capital Gains**<br>| **Net Unrealized** <br>**Appreciation/** <br>**(Depreciation)**<br>| **Total** |
| Growth Fund | $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $6431 | &nbsp;&nbsp; $64847 | &nbsp;&nbsp; $71278 |
| Large Cap Growth Fund |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 55248 | &nbsp;&nbsp; 751679 | &nbsp;&nbsp; 806927 |
| Mid Cap Value Fund |  | &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; 1 | &nbsp;&nbsp; 245 | &nbsp;&nbsp; 245 |
| Small-Mid Cap Core Fund | 95 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1696 | &nbsp;&nbsp; 9548 | &nbsp;&nbsp; 11339 |
| Small-Mid Cap Growth Fund |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 27913 | &nbsp;&nbsp; 165273 | &nbsp;&nbsp; 193186 |
| Small-Mid Cap Value Fund |  | &nbsp;&nbsp; (148)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 303 | &nbsp;&nbsp; 155 |
| Small Cap Growth Fund |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 1085 | &nbsp;&nbsp; 98655 | &nbsp;&nbsp; 99740 |
| Small Cap Value Fund | 1688 | &nbsp;&nbsp; (72381)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 131907 | &nbsp;&nbsp; 61214 |
| Global Leaders Fund |  | &nbsp;&nbsp; (77)<br>| &nbsp;&nbsp; 124 | &nbsp;&nbsp; 2752 | &nbsp;&nbsp; 2799 |
| International Leaders Fund |  | &nbsp;&nbsp; (5473)<br>| &nbsp;&nbsp; 16271 | &nbsp;&nbsp; 252574 | &nbsp;&nbsp; 263372 |
| International Growth Fund |  | &nbsp;&nbsp; (5843)<br>| &nbsp;&nbsp; 44893 | &nbsp;&nbsp; 269070 | &nbsp;&nbsp; 308120 |
| Institutional International Growth Fund |  | &nbsp;&nbsp; (4380)<br>| &nbsp;&nbsp; 35275 | &nbsp;&nbsp; 196167 | &nbsp;&nbsp; 227062 |
| International Small Cap Growth Fund | 238 | &nbsp;&nbsp; (20526)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 24556 | &nbsp;&nbsp; 4268 |
| Emerging Markets Leaders Fund |  | &nbsp;&nbsp; (57480)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 20026 | &nbsp;&nbsp; (37454)<br>|
| Emerging Markets Growth Fund | 601 | &nbsp;&nbsp; — | &nbsp;&nbsp; 21358 | &nbsp;&nbsp; 291515 | &nbsp;&nbsp; 313474 |
| Emerging Markets ex China Growth Fund | 198 | &nbsp;&nbsp; — | &nbsp;&nbsp; 552 | &nbsp;&nbsp; 13145 | &nbsp;&nbsp; 13895 |
| Emerging Markets Small Cap Growth Fund | 7431 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1771 | &nbsp;&nbsp; 56499 | &nbsp;&nbsp; 65701 |
| China Growth Fund |  | &nbsp;&nbsp; (3013)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 498 | &nbsp;&nbsp; (2515)<br>|
| Emerging Markets Debt Fund |  | &nbsp;&nbsp; (9066)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 4326 | &nbsp;&nbsp; (4740)<br>|

---

*December 31, 2025*

**84**

*Annual*

------

**Notes to Financial Statements** 

As of December 31, 2025, the Funds may have unused capital loss carryforwards available for federal income tax purposes to be applied against future capital gains, if any. Under current law, the Funds may carry forward net capital losses indefinitely to use to offset capital gains realized in future years. The following table details the Funds' available capital loss carryforwards as of December 31, 2025, and the capital loss carryforwards utilized by the Funds in 2025 (in thousands):

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Available Capital Loss Carryforwards** | **Available Capital Loss Carryforwards** | **Available Capital Loss Carryforwards** | **Capital Loss** <br>**Carryforwards** <br>**Utilized in 2025** |
| **Fund** | **Short Term** | **Long Term** | **Total** | **Capital Loss** <br>**Carryforwards** <br>**Utilized in 2025** |
| Mid Cap Value Fund | $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— | &nbsp;&nbsp; $10 |
| Small-Mid Cap Value Fund | 86 | &nbsp;&nbsp; 62 | &nbsp;&nbsp; 148 | &nbsp;&nbsp; — |
| Small Cap Value Fund | 14835 | &nbsp;&nbsp; 57546 | &nbsp;&nbsp; 72381 | &nbsp;&nbsp; — |
| International Leaders Fund |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 40183 |
| International Small Cap Growth Fund | 20526 | &nbsp;&nbsp; — | &nbsp;&nbsp; 20526 | &nbsp;&nbsp; 29031 |
| Emerging Markets Leaders Fund | 42258 | &nbsp;&nbsp; 15108 | &nbsp;&nbsp; 57366 | &nbsp;&nbsp; 34924 |
| Emerging Markets Growth Fund |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 76195 |
| Emerging Markets ex China Growth Fund |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 23 |
| China Growth Fund | 2086 | &nbsp;&nbsp; 924 | &nbsp;&nbsp; 3010 | &nbsp;&nbsp; 36 |
| Emerging Markets Debt Fund | 4633 | &nbsp;&nbsp; 4384 | &nbsp;&nbsp; 9017 | &nbsp;&nbsp; 423 |

---

In order to meet certain excise tax distribution requirements, the Funds are required to measure and distribute annually, net capital gains realized during a twelve month period ending October 31 and net investment income earned during a twelve month period ending December 31. In connection with this, the Funds are permitted for tax purposes to defer into their next fiscal year qualified late year losses. Qualified late year capital losses are any short term or long term capital losses incurred between November 1 and the end of their fiscal year, December 31. Qualified late year ordinary losses are comprised of losses related to swaps, foreign currency and PFICs incurred between November 1 and the end of their fiscal year, December 31.

As of December 31, 2025, the following Funds deferred, on a tax basis, qualified late year losses of (in thousands):

---

| | | |
|:---|:---|:---|
|  | **Qualified Late Year Losses** | **Qualified Late Year Losses** |
| **Fund** | **Ordinary** <br>**Income**<br>| **Net** <br>**Capital**<br>|
| Mid Cap Value Fund | $— | &nbsp;&nbsp; $1 |
| Global Leaders Fund | 77 | &nbsp;&nbsp; — |
| International Leaders Fund | 5473 | &nbsp;&nbsp; — |
| International Growth Fund | 5843 | &nbsp;&nbsp; — |
| Institutional International Growth Fund | 4380 | &nbsp;&nbsp; — |
| Emerging Markets Leaders Fund | 114 | &nbsp;&nbsp; — |
| China Growth Fund | 3 | &nbsp;&nbsp; — |
| Emerging Markets Debt Fund | 49 | &nbsp;&nbsp; — |

---

*(e)* *Repurchase Agreements*

In a repurchase agreement, a Fund buys a security at one price and at the time of sale, the seller agrees to repurchase the security at a mutually agreed upon time and price (usually within seven days). The repurchase agreement thereby determines the yield during the purchaser's holding period, while the seller's obligation to repurchase is secured by the value of the underlying collateral. The Adviser monitors, on an ongoing basis, the value of the underlying collateral to ensure that the value always equals or exceeds the repurchase price plus accrued interest. Repurchase agreements may involve certain risks in the event of a default or insolvency of the other party to the agreement, including possible delays or restrictions upon a Fund's ability to dispose of the underlying collateral. The risk to a Fund is limited to the ability of the seller to pay the agreed upon sum on the delivery date. In the event of default, a repurchase agreement provides that a Fund is entitled to sell the underlying collateral. The loss, if any, to a Fund will be the difference between the proceeds from the sale and the repurchase price. However, if bankruptcy proceedings are commenced with respect to the seller of the security, disposition of the collateral by the Fund may be delayed or limited. The Funds have master repurchase agreements which allow the Funds to offset amounts owed to a counterparty with amounts owed from the same counterparty, including any collateral, in the event the counterparty defaults. Each Fund's outstanding repurchase agreements, if any, and related collateral, are shown on the Fund's Portfolio of Investments. Although no definitive creditworthiness criteria are used, the Adviser reviews the creditworthiness of the banks and non-bank dealers with which a Fund enters into repurchase agreements to evaluate those risks. A Fund may, for tax purposes, deem repurchase agreements collateralized by U.S. Government securities to be investments in U.S. Government securities.

*December 31, 2025*

**85**

*William Blair Funds*

------

**Notes to Financial Statements** 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

*(f)* *Trustees & Officers* 

The Trustees and Officers affiliated with the Adviser receive no compensation from the Trust. Trustees who are not affiliated with the Adviser receive compensation from the Trust in the form of an annual retainer plus fees for attendance at Board and Committee meetings. The Lead Independent Trustee and the Chairs of the Audit Committee, Compliance Committee and Nominating and Governance Committee each receive an additional retainer for serving in such positions. Additionally, each independent trustee is entitled to reimbursement of expenses related to his or her duties as a Trustee of the Trust. For the year ended December 31, 2025, Trustee Fees were $1,121 (in thousands) in aggregate for the Trust.

*(g)* *Use of Estimates*

The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements. Actual results may differ from those estimates.

*(h)* *Indemnification*

In the normal course of business, the Funds have entered into contracts in which the Funds agree to indemnify the other party or parties against various potential costs or liabilities. The Funds' maximum exposure under these arrangements is unknown. No claim has been made for indemnification pursuant to any such agreement of the Funds.

**(3)** **Valuation**

*(a)* *Investment Valuation*

The value of U.S. equity securities, including exchange-traded funds, is determined by valuing securities traded on national securities markets or in the over-the-counter ("OTC") markets at the last sale price or, if applicable, the official closing price or, in the absence of a recent sale on the date of determination, at the mean between the last reported bid and ask prices.

The value of foreign equity securities is generally determined based upon the last sale price on the foreign exchange or market on which it is primarily traded and in the currency of that market as of the close of the appropriate exchange or, if there have been no sales during that day, at the mean between the last reported bid and ask prices. The Adviser has determined that the passage of time between when the foreign exchanges or markets close and when the Funds compute their net asset values could cause the value of foreign equity securities to no longer be representative or accurate and, as a result, may necessitate that such securities be fair valued. Accordingly, for foreign equity securities, the Funds may use an independent pricing service to fair value price the security as of the close of regular trading on the NYSE. As a result, a Fund's value for a foreign security may be different from the last sale price (or the mean between the last reported bid and ask prices). As of December 31, 2025, fair valuation estimates for foreign equity securities were not obtained.

Fixed income securities are generally valued using evaluated prices provided by an independent pricing service. The evaluated prices are formed using various market inputs that the pricing service believes accurately represent the market value of a security at a particular point in time. The pricing service determines evaluated prices for fixed income securities using inputs including, but not limited to, recent transaction prices for such securities, dealer quotes, transaction prices for other securities with similar characteristics, collateral characteristics, credit quality, payment history, liquidity and market conditions.

Repurchase agreements are valued at cost, which approximates fair value.

Forward foreign currency contracts are valued on the basis of the value of the underlying currencies at the prevailing currency exchange rate as supplied by an independent pricing service.

Swaps that are centrally cleared through an exchange are valued at the most recent settlement price provided by the exchange on which they are cleared. Total return swaps on equities, equity baskets, indices and other financial instruments are valued by an independent pricing service, or if unavailable, based on the security's or instrument's underlying reference asset.

Option contracts on securities, currencies and other financial instruments traded on one or more exchanges are valued at their most recent sale price on the exchange on which they are traded most extensively. Option contracts on foreign indices are valued at the settlement price. If there were no sales that day or if no settlement price is available, such option contracts are valued at the mean between the last reported bid and ask prices. Option contracts traded in the OTC market shall be valued by an independent pricing service.

Securities, and other assets, for which a market quotation is not available or is deemed unreliable (e.g., securities affected by unusual or extraordinary events, such as natural disasters or securities affected by market or economic events, such as

*December 31, 2025*

**86**

*Annual*

------

**Notes to Financial Statements** 

bankruptcy filings), or the value of which is affected by a significant valuation event, are valued at a fair value. Pursuant to Rule 2a-5 under the 1940 Act, the Board of Trustees has designated the Adviser as the valuation designee to perform fair value determinations for the Funds. The value of these fair valued securities may be different from the last sale price (or the mean between the last reported bid and ask prices), and there is no guarantee that a fair valued security will be sold at the price at which a Fund is carrying the security.

*(b)* *Fair Value Measurements*

Fair value is defined as the price that a Fund would receive upon selling a security in an orderly transaction to an independent buyer in the principal or most advantageous market for the investment. Various inputs are used in determining the value of a Fund's investments. A three-tier hierarchy of inputs is used to classify fair value measurements for disclosure purposes. The three-tier hierarchy of inputs is summarized in the three broad levels listed below:

&nbsp;&nbsp;&nbsp;&nbsp;• Level 1—Quoted prices (unadjusted) in active markets for an identical security.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;• Level 2—Prices determined using other significant observable inputs. Observable inputs are inputs that other market participants would use in pricing a security. These may include quoted prices for similar securities, interest rates, prepayment speeds, credit risk, and others. In addition, other observable inputs such as foreign exchange rates, benchmark securities indices and foreign futures contracts may be utilized in the valuation of certain foreign securities when significant events occur between the last sale on the foreign securities exchange and the time at which the net asset value of the Fund is calculated.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;• Level 3—Prices determined using significant unobservable inputs. In situations where quoted prices or observable inputs are unavailable (for example, when there is little or no market activity for an investment), unobservable inputs may be used. Unobservable inputs reflect the Fund's own assumptions about the factors market participants would use in pricing an investment, and are based on the best information available.

The value of investments in securities and other financial instruments, segregated by their hierarchical input levels used in determining fair value and by security class or other financial instruments, are shown at the end of each Fund's Portfolio of Investments.

The inputs or methodology used for valuing an investment are not necessarily an indication of the risk associated with investing in those securities.

A description of the valuation methodologies applied to the Funds' major categories of assets and liabilities measured at fair value on a recurring basis is as follows:

*Exchange-Traded Securities*

Securities traded on a national securities exchange (or reported on the NASDAQ national market), including exchange-traded funds, are stated at the last reported sales price on the day of valuation. Other securities traded in the OTC market and listed securities for which no sale was reported on that date are stated at the mean between the last reported bid and ask prices. To the extent these securities are actively traded and valuation adjustments are not applied, they are categorized as Level 1 of the fair value hierarchy. Securities traded on inactive markets or valued by reference to similar instruments are generally categorized as Level 2 of the fair value hierarchy.

*Fixed Income Securities*

Fixed income securities are generally valued using evaluated prices provided by an independent pricing service. The evaluated prices are formed using various market inputs that the pricing service believes accurately represent the fair value of a security at a particular point in time. The pricing service determines evaluated prices for fixed income securities using inputs including, but not limited to, recent transaction prices for such securities, dealer quotes, transaction prices for other securities with similar characteristics, collateral characteristics, credit quality, payment history, liquidity and market conditions. Securities that use similar valuation techniques and observable inputs as described above are categorized as Level 2 of the fair value hierarchy.

*Repurchase Agreements*

Repurchase agreements are valued at cost, which approximates fair value. Repurchase agreements are categorized as Level 2 of the fair value hierarchy.

*December 31, 2025*

**87**

*William Blair Funds*

------

**Notes to Financial Statements** 

*Derivative Instruments*

Listed derivatives, such as certain options and futures contracts, that are actively traded are valued based on quoted prices from the exchange on which they are traded most extensively and are categorized as Level 1 of the fair value hierarchy. OTC derivative contracts include forward foreign currency contracts, swap and certain option contracts related to interest rates, foreign currencies, the credit standing of reference entities, equity prices, or commodity prices. Depending on the product and the terms of the transaction, the fair value of OTC derivative products can be modeled by independent pricing services taking into account the counterparties' creditworthiness and using a series of techniques, including simulation models. Many pricing models do not entail material subjectivity because the methodologies employed do not necessitate significant judgments and the pricing inputs are observed from actively quoted markets, as is the case of forward foreign currency contracts and interest rate swaps. A substantial majority of OTC derivative products held by a Fund are valued using such models and are categorized as Level 2 of the fair value hierarchy.

*Level 3 Securities*

The fair value estimates for the Level 3 securities in the Small-Mid Cap Growth Fund and Small Cap Growth Fund were determined in good faith by the Adviser pursuant to the Trust's Valuation Procedures. There were various factors considered in reaching the fair value determination, including, but not limited to, the following: the type of security, the extent of public trading of the security, information obtained for the security, and analysis of the company's performance and market trends that influence its performance. The Level 3 securities represented 0.00% and 0.00% as a percentage of net assets in the Small-Mid Cap Growth Fund and Small Cap Growth Fund, respectively.

*December 31, 2025*

**88**

*Annual*

------

**Notes to Financial Statements** 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**(4)** **Transactions with Affiliates**

*(a)* *Management and Expense Limitation Agreements*

Each Fund has a management agreement with the Adviser for investment management, clerical, bookkeeping and administrative services. Each Fund pays the Adviser an annual management fee, which is accrued daily and paid monthly, based on a specified percentage of the Fund's average daily net assets. Each Fund's annual management fee rate is as follows:

---

| | |
|:---|:---|
| **U.S. Equity Funds** |  |
| Growth Fund | 0.75% |
| Large Cap Growth Fund | 0.60% |
| Mid Cap Value Fund | 0.70% |
| Small-Mid Cap Core Fund | 0.90% |
| Small-Mid Cap Growth Fund | 0.94% |
| Small-Mid Cap Value Fund | 0.80% |
| Small Cap Growth Fund | 0.94% |
| Small Cap Value Fund | 0.75% |

---

---

| | |
|:---|:---|
| **Emerging Markets Debt Fund** |  |
| Emerging Markets Debt Fund | 0.65% |

---

---

| | |
|:---|:---|
| **Global Equity Fund** |  |
| Global Leaders Fund | 0.85% |

---

---

| | |
|:---|:---|
| **International Equity Funds** |  |
| International Leaders Fund | 0.85% |
| International Growth Fund<sup>1</sup>: |  |
| First $10 billion | 0.85% |
| Next $5 billion | 0.825% |
| In excess of $15 billion | 0.80% |
| Institutional International Growth Fund<sup>2</sup>: |  |
| First $10 billion | 0.85% |
| Next $5 billion | 0.825% |
| In excess of $15 billion | 0.80% |
| International Small Cap Growth Fund | 1.00% |
| Emerging Markets Leaders Fund | 0.94% |
| Emerging Markets Growth Fund | 0.94% |
| Emerging Markets ex China Growth Fund | 0.94% |
| Emerging Markets Small Cap Growth Fund | 1.10% |
| China Growth Fund | 0.94% |

---

------

<sup>1</sup> Effective May 1, 2025. Prior to May 1, 2025, the International Growth Fund paid the Adviser a contractual management fee equal to 0.94% of the first $3 billion of the Fund's average daily net assets; 0.90% of the next $2 billion of the Fund's average daily net assets; 0.85% of the next $5 billion of the Fund's average daily net assets; 0.825% of the next $5 billion of the Fund's average daily net assets; plus 0.80% of the Fund's average daily net assets over $15 billion. 

<sup>2</sup> Effective May 1, 2025. Prior to May 1, 2025, the Institutional International Growth Fund paid the Adviser a contractual management fee equal to 0.94% of the first $1.875 billion of the Fund's average daily net assets; 0.90% of the next $625 million of the Fund's average daily net assets; 0.875% of the next $2.5 billion of average daily net assets; 0.85% of the next $5 billion of average daily net assets; 0.825% of the next $5 billion of average daily net assets; plus 0.80% of average daily net assets over $15 billion. 

*December 31, 2025*

**89**

*William Blair Funds*

------

**Notes to Financial Statements** 

The Funds have also entered into an Amended and Restated Expense Limitation Agreement with the Adviser. Under the terms of the agreement, the Adviser will waive its management fee and/or reimburse a Fund for certain operating expenses, subject to certain excluded expenses, in excess of the agreed upon rate through April 30, 2026. Excluded expenses include interest expenses, taxes, brokerage commissions, acquired fund fees and expenses, dividend and interest expenses on short sales, other investment related costs and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of a Fund's business. The amount the Adviser owes a Fund as of the reporting date is recorded as Receivable from Adviser in the Statements of Assets and Liabilities. The Adviser reimburses the Funds on a monthly basis. The Adviser will waive fees and/or reimburse expenses to the extent that the total operating expenses for the stated class of the Funds, subject to certain excluded expenses, exceed the following rates (as a percentage of average daily net assets):

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class I** | **Class I** | **Institutional/Class R6** | **Institutional/Class R6** |
| **Fund** | **Effective** <br>**May 1, 2025** <br>**through** <br>**April 30,** <br>**2026**<br>| **Effective** <br>**May 1, 2024** <br>**through** <br>**April 30,** <br>**2025**<br>| **Effective** <br>**May 1, 2025** <br>**through** <br>**April 30,** <br>**2026**<br>| **Effective** <br>**May 1, 2024** <br>**through** <br>**April 30,** <br>**2025**<br>| **Effective** <br>**May 1, 2025** <br>**through** <br>**April 30,** <br>**2026**<br>| **Effective** <br>**May 1, 2024** <br>**through** <br>**April 30,** <br>**2025**<br>|
| Growth Fund | 1.20<br> %<br>| 1.20<br> %<br>| 0.95<br> %<br>| 0.95<br> %<br>| 0.90<br> %<br>| 0.90<br> %<br>|
| Large Cap Growth Fund | 0.90<br> %<br>| 0.90<br> %<br>| 0.65<br> %<br>| 0.65<br> %<br>| 0.60<br> %<br>| 0.60<br> %<br>|
| Mid Cap Value Fund | N/A | &nbsp;&nbsp; N/A | 0.75<br> %<br>| 0.75<br> %<br>| 0.70<br> %<br>| 0.70<br> %<br>|
| Small-Mid Cap Core Fund | N/A | &nbsp;&nbsp; N/A | 0.95<br> %<br>| 0.95<br> %<br>| 0.90<br> %<br>| 0.90<br> %<br>|
| Small-Mid Cap Growth Fund | 1.24<br> %<br>| 1.24<br> %<br>| 0.99<br> %<br>| 0.99<br> %<br>| 0.94<br> %<br>| 0.94<br> %<br>|
| Small-Mid Cap Value Fund | N/A | &nbsp;&nbsp; N/A | 0.85<br> %<br>| 0.85<br> %<br>| 0.80<br> %<br>| 0.80<br> %<br>|
| Small Cap Growth Fund | 1.24<br> %<br>| 1.24<br> %<br>| 0.99<br> %<br>| 0.99<br> %<br>| 0.94<br> %<br>| 0.94<br> %<br>|
| Small Cap Value Fund | 1.15<br> %<br>| 1.15<br> %<br>| 0.89<br> %<br>| 0.89<br> %<br>| 0.85<br> %<br>| 0.85<br> %<br>|
| Global Leaders Fund | 1.15<br> %<br>| 1.15<br> %<br>| 0.90<br> %<br>| 0.90<br> %<br>| 0.85<br> %<br>| 0.85<br> %<br>|
| International Leaders Fund | 1.15<br> %<br>| 1.15<br> %<br>| 0.90<br> %<br>| 0.90<br> %<br>| 0.85<br> %<br>| 0.85<br> %<br>|
| International Growth Fund | 1.15<br> %<br>| 1.24<br> %<br>| 0.90<br> %<br>| 0.99<br> %<br>| 0.85<br> %<br>| 0.94<br> %<br>|
| Institutional International Growth Fund | N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | &nbsp;&nbsp; N/A | 0.85<br> %<br>| 0.94<br> %<br>|
| International Small Cap Growth Fund | 1.35<br> %<br>| 1.35<br> %<br>| 1.10<br> %<br>| 1.10<br> %<br>| 1.05<br> %<br>| 1.05<br> %<br>|
| Emerging Markets Leaders Fund | 1.24<br> %<br>| 1.24<br> %<br>| 0.99<br> %<br>| 0.99<br> %<br>| 0.94<br> %<br>| 0.94<br> %<br>|
| Emerging Markets Growth Fund | 1.24<br> %<br>| 1.24<br> %<br>| 0.99<br> %<br>| 0.99<br> %<br>| 0.94<br> %<br>| 0.94<br> %<br>|
| Emerging Markets ex China Growth Fund | N/A | &nbsp;&nbsp; N/A | 0.99<br> %<br>| 0.99<br> %<br>| 0.94<br> %<br>| 0.94<br> %<br>|
| Emerging Markets Small Cap Growth Fund | 1.40<br> %<br>| 1.40<br> %<br>| 1.15<br> %<br>| 1.15<br> %<br>| 1.10<br> %<br>| 1.10<br> %<br>|
| China Growth Fund | N/A | &nbsp;&nbsp; N/A | 0.99<br> %<br>| 0.99<br> %<br>| 0.94<br> %<br>| 0.94<br> %<br>|
| Emerging Markets Debt Fund | N/A | &nbsp;&nbsp; N/A | 0.70<br> %<br>| 0.70<br> %<br>| 0.65<br> %<br>| 0.65<br> %<br>|

---

The fee waivers and/or expense reimbursements received by each class are reported in the Statements of Operations.

The Adviser is entitled to recoupment of previously waived fees and reimbursed expenses for a period of three years subsequent to a Fund's commencement of operations to the extent that such recoupment does not cause the Fund's annual operating expenses (after the recoupment is taken into account) to exceed both (1) the expense limit in place when such amounts were waived or reimbursed and (2) the Fund's current expense limitation. The total amounts available for recoupment as of December 31, 2025 were as follows (in thousands):

---

| | | |
|:---|:---|:---|
| **Fund** | **Available for** <br>**Recoupment**<br>| **Expiration of** <br>**Recoupment**<br>|
| Small-Mid Cap Value Fund | $337 | August 17, 2026 |

---

*December 31, 2025*

**90**

*Annual*

------

**Notes to Financial Statements** 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

*(b)* *Underwriting and Distribution Services Agreements*

Pursuant to separate Underwriting and Distribution Agreements, WBC is the principal underwriter and distributor for the continuous offering of shares of the Trust and acts as agent of the Trust in the sale of its shares. The Underwriting Agreement provides that the Distributor will use its best efforts to distribute the Trust's shares. The Distributor is not compensated under the Underwriting Agreement.

Each Fund, except the Mid Cap Value, Small-Mid Cap Core, Small-Mid Cap Value, Emerging Markets ex China Growth, China Growth, Emerging Markets Debt and Institutional International Growth Funds, has a Distribution Agreement with WBC for distribution services to the Funds' Class N shares. Each Fund pays WBC an annual fee, payable monthly, based on a specified percentage of its average daily net assets of Class N shares. The annual rate expressed as a percentage of average daily net assets for Class N is 0.25% for all Funds. Pursuant to the Distribution Agreement, WBC enters into related selling group agreements with various firms at various rates for sales of the Funds' Class N shares.

**(5)** **Investment Transactions**

Investment transactions, excluding U.S. government securities and short-term securities, for the year ended December 31, 2025, were as follows (in thousands):

---

| | | |
|:---|:---|:---|
| **Fund** | **Purchases** | **Sales** |
| Growth Fund | $145271 | &nbsp;&nbsp; $192490 |
| Large Cap Growth Fund | 1105425 | &nbsp;&nbsp; 1595228 |
| Mid Cap Value Fund | 441 | &nbsp;&nbsp; 916 |
| Small-Mid Cap Core Fund | 103946 | &nbsp;&nbsp; 106386 |
| Small-Mid Cap Growth Fund | 829627 | &nbsp;&nbsp; 1465814 |
| Small-Mid Cap Value Fund | 1290 | &nbsp;&nbsp; 1272 |
| Small Cap Growth Fund | 884442 | &nbsp;&nbsp; 847013 |
| Small Cap Value Fund | 401608 | &nbsp;&nbsp; 841267 |
| Global Leaders Fund | 33717 | &nbsp;&nbsp; 76065 |
| International Leaders Fund | 1024621 | &nbsp;&nbsp; 1298788 |
| International Growth Fund | 984530 | &nbsp;&nbsp; 1407319 |
| Institutional International Growth Fund | 728347 | &nbsp;&nbsp; 928320 |
| International Small Cap Growth Fund | 106123 | &nbsp;&nbsp; 158370 |
| Emerging Markets Leaders Fund | 112817 | &nbsp;&nbsp; 214309 |
| Emerging Markets Growth Fund | 777445 | &nbsp;&nbsp; 867434 |
| Emerging Markets ex China Growth Fund | 46007 | &nbsp;&nbsp; 35144 |
| Emerging Markets Small Cap Growth Fund | 938057 | &nbsp;&nbsp; 1009377 |
| China Growth Fund | 1406 | &nbsp;&nbsp; 1491 |
| Emerging Markets Debt Fund | 63299 | &nbsp;&nbsp; 63248 |

---

**(6)** **Financial Derivative Instruments**

Each Fund may use derivative instruments to maintain liquidity, to provide hedging, or in anticipation of changes in the composition of its portfolio holdings or as otherwise provided in each Fund's prospectus. The derivative instruments held as of December 31, 2025 as disclosed in each Fund's Portfolio of Investments, are representative of each Fund's derivative instrument trading activity during the year ended December 31, 2025.

Derivative transactions carry counterparty risk as they are based on contracts between a Fund and the applicable counterparty. For exchange-traded or cleared derivative contracts, such counterparty risk is limited due to the role of the exchange or clearinghouse. OTC derivative contracts, however, are exposed to counterparty risk in the amount of unrealized gains, net of collateral held, for the duration of the contract.

The Emerging Markets Debt Fund is subject to certain netting arrangements through International Swaps and Derivatives Association, Inc. Master Agreements and Credit Support Annexes ("ISDAs"). The ISDAs maintain provisions for general obligations, representations, agreements, collateral and events of default or termination. The ISDAs cover certain OTC derivative securities entered into by the Emerging Markets Debt Fund with various counterparties and allow the Emerging Markets Debt Fund to close out and net its total exposure to a counterparty in the event of a default.

*December 31, 2025*

**91**

*William Blair Funds*

------

**Notes to Financial Statements** 

*Forward Foreign Currency Contracts*

The Global Equity, International Equity and Emerging Markets Debt Funds may enter into forward foreign currency contracts. When entering into a forward foreign currency contract, a Fund agrees to receive or deliver a fixed quantity of foreign currency for an agreed-upon price on an agreed future date. A Fund's net equity therein, representing unrealized gain or loss on the contracts as measured by the difference between the forward foreign exchange rates at the dates of entry into the contracts and the forward rates at the reporting date. These instruments may involve market risk, credit risk, or both kinds of risks in excess of the amount recognized in the Portfolio of Investments. Risks arise from the possible inability of counterparties to meet the terms of their contracts and from the price movements in currencies.

*Options*

The purchase or sale of an option by a Fund involves the payment or receipt of a premium by the Fund and the corresponding right or obligation, as the case may be, either to purchase or sell the underlying security, commodity, or other instrument for a specific price at a certain time or during a certain period. Purchasing options involves the risk that the underlying instrument will not change price in the manner expected, so the Fund loses its premium. Writing options involves potentially greater risk because the Fund is exposed to the extent of the actual price movement in the underlying security rather than only the amount of the premium paid (which could result in a potentially unlimited loss). OTC options also involve counterparty credit risk.

*Swap Contracts*

Swap agreements may include total return, interest rate, securities index, commodity, security, currency exchange rate, credit default index, volatility and variance swaps. Cleared swaps are transacted through futures commission merchants that are members of central clearing houses with the clearing house serving as a central counterparty similar to transactions in futures contracts. In a standard "swap" transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments. The gross returns to be exchanged or "swapped" between the parties are calculated with respect to a "notional amount" (i.e., the change in the value of a particular dollar amount invested, for example, at a particular interest rate, in a particular foreign currency, or in a "basket" of securities representing a particular index). Swap agreements are subject to the risk that the counterparty to the swap will default on its obligation to pay a Fund and the risk that a Fund will not be able to meet its obligations to pay the counterparty to the swap. Swap agreements may also involve fees, commissions or other costs that may reduce a Fund's gains from a swap agreement or may cause a Fund to lose money. To the extent permitted by its investment policies and restrictions, a Fund may invest in the following types of swaps:

Credit Default Swaps—A Fund may invest in credit default swaps as a means of "buying" credit protection (i.e., attempting to mitigate the risk of default or credit quality deterioration in some portion of a Fund's holdings) or "selling" credit protection (i.e., attempting to gain exposure to an underlying issuer's credit quality characteristics without directly investing in that issuer). A credit default swap is a contract between a buyer and a seller of protection against a pre-defined credit event (e.g., a ratings downgrade or default) on an underlying reference obligation, which may be a single debt instrument or baskets or indices of securities. Under current regulatory requirements, a Fund may be a buyer or seller of a credit default swap. As a seller of protection on credit default swap agreements, a Fund will generally receive from the buyer of protection a fixed rate of income throughout the term of the swap provided that there is no credit event. A Fund adds leverage to its portfolio because the Fund is subject to investment exposure on the notional amount of the swap. The maximum potential amount of future payments that a Fund as a seller of protection could be required to make under a credit default swap agreement equals the notional amount of the agreement. Notional amounts of each individual credit default swap agreement outstanding as of the period end for which a Fund is the seller of protection are disclosed in the Fund's Portfolio of Investments. These potential amounts would be partially offset by any recovery values of the respective referenced obligations, upfront payments received upon entering into the agreement, or net amounts received from the settlement of buy protection credit default swap agreements entered into by the same Fund for the same referenced entity or entities. For credit default swap contracts on credit indices, the quoted market prices and resulting values serve as an indicator of the payment performance risk. Increasing market values, in absolute terms when compared to the notional amount of the swap, typically represent deterioration of the referenced entities' credit soundness and a greater likelihood or risk of default or other credit event occurring as defined under the terms of the swap.

Interest Rate Swap—A Fund may invest in interest rate swaps to gain or mitigate exposure to changes in interest rates. Interest rate swap agreements involve a commitment between parties to pay either a fixed interest rate or a floating interest rate based on a notional amount of principal. The parties make payments at predetermined intervals throughout the life of the swap. As a payer, a Fund would make the fixed payment and receive the floating payment. As a receiver, a Fund would make the floating payment and receive the fixed payment.

*December 31, 2025*

**92**

*Annual*

------

**Notes to Financial Statements** 

Total Return Swap—A Fund may invest in total return swaps to gain or mitigate exposure to an underlying security, or securities. Total return swap agreements may involve commitments to pay interest in exchange for the return on the underlying security, or securities. At maturity, a net cash flow is exchanged between the parties based on the total return of the underlying security, or securities, less a financing rate. As a receiver in the transaction, a Fund would receive a payment for a positive return and would make a payment for a negative return. As a payer in the transaction, a Fund would make a payment for a positive return and would receive a payment for a negative return.

The following table presents the value of financial derivative instruments, by Fund and primary risk exposure, as of December 31, 2025, and their respective location in the Statements of Assets and Liabilities (in thousands):

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Assets** | **Assets** | **Liabilities** | **Liabilities** |
| **Fund and** <br>**Primary Risk Exposure**<br>| **Statements of Assets** <br>**and Liabilities**<br>| **Value** | **Statements of Assets** <br>**and Liabilities**<br>| **Value** |
| **Emerging Markets Debt Fund** |  |  |  |  |
| Credit | &nbsp;&nbsp; Receivable for variation margin on <br> centrally cleared swaps<sup>1</sup> <br>| &nbsp;&nbsp; $192 | &nbsp;&nbsp; Payable for variation margin on <br> centrally cleared swaps<sup>1</sup> <br>| &nbsp;&nbsp; $272 |
| Currency | &nbsp;&nbsp; Unrealized appreciation on forward <br> foreign currency contracts<br>| &nbsp;&nbsp; 5 | &nbsp;&nbsp; Unrealized depreciation on forward <br> foreign currency contracts<br>| &nbsp;&nbsp; 56 |
| Currency | Investments in securities, at value | &nbsp;&nbsp; 74 | Options written, at value | &nbsp;&nbsp; — |
| Interest Rate | &nbsp;&nbsp; Receivable for variation margin on <br> centrally cleared swaps<sup>1</sup> <br>| &nbsp;&nbsp; 369 | &nbsp;&nbsp; Payable for variation margin on <br> centrally cleared swaps<sup>1</sup> <br>| &nbsp;&nbsp; 117 |

---

------

---

| | |
|:---|:---|
| 1 | The table above includes cumulative appreciation/(depreciation) on centrally cleared swaps as reported in the Fund's Portfolio of Investments. <br> Receivable/payable for variation margin on centrally cleared swaps as reported in the Fund's Statement of Assets and Liabilities represents the current <br> day's variation margin.<br>|

---

The following table indicates the effect of derivatives, by Fund and primary risk exposure, in the Statements of Operations for the year ended December 31, 2025 (in thousands):

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Net Realized Gain (Loss)** | **Net Realized Gain (Loss)** | **Change in Net Unrealized** <br>**Appreciation (Depreciation)** | **Change in Net Unrealized** <br>**Appreciation (Depreciation)** |
| **Fund and** <br>**Primary Risk Exposure**<br>| **Statements of Operations** | **Value** | **Statements of Operations** | **Value** |
| **Emerging Markets Debt Fund** |  |  |  |  |
| Credit | Swaps | &nbsp;&nbsp; $34 | Swaps | &nbsp;&nbsp; $(106)<br>|
| Currency | Forward foreign currency contracts | &nbsp;&nbsp; (173)<br>| Forward foreign currency contracts | &nbsp;&nbsp; (111)<br>|
| Currency | Investments in securities | &nbsp;&nbsp; (42)<br>| Investments in securities | &nbsp;&nbsp; (23)<br>|
| Interest Rate | Investments in securities | &nbsp;&nbsp; (154)<br>| Investments in securities | &nbsp;&nbsp; — |
| Interest Rate | Written Options | &nbsp;&nbsp; 30 | Written Options | &nbsp;&nbsp; — |
| Interest Rate | Swaps | &nbsp;&nbsp; (316)<br>| Swaps | &nbsp;&nbsp; 524 |

---

The following table is a summary by counterparty of the derivative instruments and collateral pledged/(received) included in the Fund's Statement of Assets and Liabilities at December 31, 2025 (in thousands):

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Financial Derivative Assets** | **Financial Derivative Assets** | **Financial Derivative Assets** | **Financial Derivative Liabilities** | **Financial Derivative Liabilities** |  |  |  |
| **Counterparty** | **Forward** <br>**Foreign** <br>**Currency** <br>**Contracts**<br>| **Purchased** <br>**Options**<br>| **Total** | **Forward** <br>**Foreign** <br>**Currency** <br>**Contracts**<br>| **Total** | **Net** <br>**Market** <br>**Value**<br>| **Collateral** <br>**Pledged** <br>**(Received)**<br>| **Net** <br>**Exposure**<br>|
| **Emerging Markets Debt Fund** | **Emerging Markets Debt Fund** |  |  |  |  |  |  |  |
| Citibank N.A. | $5 | &nbsp;&nbsp; $74 | &nbsp;&nbsp; $79 | &nbsp;&nbsp; $(56)<br>| &nbsp;&nbsp; $(56)<br>| &nbsp;&nbsp; $23 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $23 |
|  | $5 | &nbsp;&nbsp; $74 | &nbsp;&nbsp; $79 | &nbsp;&nbsp; $(56)<br>| &nbsp;&nbsp; $(56)<br>|  |  |  |

---

The net exposure represents the amount due from/(due to) the counterparty in the event of default. Any net exposure is generally due to changes in market value of the underlying derivative instruments on the last day of the period as timing of collateral movement occurs the following day.

*December 31, 2025*

**93**

*William Blair Funds*

------

**Notes to Financial Statements** 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**(7)** **Fund Share Transactions**

The following tables summarize the activity in capital shares of each Fund for the year ended December 31, 2025 (in thousands):

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $708 | &nbsp;&nbsp; $8754 | &nbsp;&nbsp; $6279 | &nbsp;&nbsp; $3183 | &nbsp;&nbsp; 84 | &nbsp;&nbsp; 1324 | &nbsp;&nbsp; 729 | &nbsp;&nbsp; 679 |
| Large Cap Growth Fund | 8543 | &nbsp;&nbsp; 11205 | &nbsp;&nbsp; 67919 | &nbsp;&nbsp; (48171)<br>| &nbsp;&nbsp; 315 | &nbsp;&nbsp; 413 | &nbsp;&nbsp; 2413 | &nbsp;&nbsp; (1685)<br>|
| Small-Mid Cap Growth Fund | 3301 | &nbsp;&nbsp; 1893 | &nbsp;&nbsp; 28873 | &nbsp;&nbsp; (23679)<br>| &nbsp;&nbsp; 140 | &nbsp;&nbsp; 77 | &nbsp;&nbsp; 1199 | &nbsp;&nbsp; (982)<br>|
| Small Cap Growth Fund | 13071 | &nbsp;&nbsp; 9412 | &nbsp;&nbsp; 42642 | &nbsp;&nbsp; (20159)<br>| &nbsp;&nbsp; 480 | &nbsp;&nbsp; 348 | &nbsp;&nbsp; 1507 | &nbsp;&nbsp; (679)<br>|
| Small Cap Value Fund | 91 | &nbsp;&nbsp; 38 | &nbsp;&nbsp; 405 | &nbsp;&nbsp; (276)<br>| &nbsp;&nbsp; 3 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 14 | &nbsp;&nbsp; (10)<br>|
| Global Leaders Fund | 606 | &nbsp;&nbsp; 1150 | &nbsp;&nbsp; 2455 | &nbsp;&nbsp; (699)<br>| &nbsp;&nbsp; 52 | &nbsp;&nbsp; 183 | &nbsp;&nbsp; 272 | &nbsp;&nbsp; (37)<br>|
| International Leaders Fund | 4777 | &nbsp;&nbsp; 1776 | &nbsp;&nbsp; 12584 | &nbsp;&nbsp; (6031)<br>| &nbsp;&nbsp; 227 | &nbsp;&nbsp; 83 | &nbsp;&nbsp; 579 | &nbsp;&nbsp; (269)<br>|
| International Growth Fund | 6350 | &nbsp;&nbsp; 39730 | &nbsp;&nbsp; 71833 | &nbsp;&nbsp; (25753)<br>| &nbsp;&nbsp; 224 | &nbsp;&nbsp; 1561 | &nbsp;&nbsp; 2618 | &nbsp;&nbsp; (833)<br>|
| International Small Cap Growth Fund | 64 | &nbsp;&nbsp; 4 | &nbsp;&nbsp; 299 | &nbsp;&nbsp; (231)<br>| &nbsp;&nbsp; 5 | &nbsp;&nbsp; — | &nbsp;&nbsp; 23 | &nbsp;&nbsp; (18)<br>|
| Emerging Markets Leaders Fund | 9506 | &nbsp;&nbsp; 7 | &nbsp;&nbsp; 9568 | &nbsp;&nbsp; (55)<br>| &nbsp;&nbsp; 882 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 884 | &nbsp;&nbsp; (1)<br>|
| Emerging Markets Growth Fund | 5986 | &nbsp;&nbsp; 15 | &nbsp;&nbsp; 9665 | &nbsp;&nbsp; (3664)<br>| &nbsp;&nbsp; 451 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 716 | &nbsp;&nbsp; (264)<br>|
| Emerging Markets Small Cap Growth <br> Fund<br>| 1378 | &nbsp;&nbsp; 332 | &nbsp;&nbsp; 2122 | &nbsp;&nbsp; (412)<br>| &nbsp;&nbsp; 65 | &nbsp;&nbsp; 16 | &nbsp;&nbsp; 101 | &nbsp;&nbsp; (20)<br>|

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $3819 | &nbsp;&nbsp; $33724 | &nbsp;&nbsp; $29778 | &nbsp;&nbsp; $7765 | &nbsp;&nbsp; 295 | &nbsp;&nbsp; 3135 | &nbsp;&nbsp; 2389 | &nbsp;&nbsp; $1041 |
| Large Cap Growth Fund | 308287 | &nbsp;&nbsp; 144712 | &nbsp;&nbsp; 628170 | &nbsp;&nbsp; (175171)<br>| &nbsp;&nbsp; 10373 | &nbsp;&nbsp; 4886 | &nbsp;&nbsp; 20887 | &nbsp;&nbsp; (5628)<br>|
| Mid Cap Value Fund | 1 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 31 | &nbsp;&nbsp; (29)<br>| &nbsp;&nbsp; 1 | &nbsp;&nbsp; — | &nbsp;&nbsp; 3 | &nbsp;&nbsp; (2)<br>|
| Small-Mid Cap Core Fund | 15325 | &nbsp;&nbsp; 1137 | &nbsp;&nbsp; 48800 | &nbsp;&nbsp; (32338)<br>| &nbsp;&nbsp; 976 | &nbsp;&nbsp; 68 | &nbsp;&nbsp; 2922 | &nbsp;&nbsp; (1878)<br>|
| Small-Mid Cap Growth Fund | 83589 | &nbsp;&nbsp; 21078 | &nbsp;&nbsp; 516476 | &nbsp;&nbsp; (411809)<br>| &nbsp;&nbsp; 3208 | &nbsp;&nbsp; 772 | &nbsp;&nbsp; 19471 | &nbsp;&nbsp; (15491)<br>|
| Small-Mid Cap Value Fund |  | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Small Cap Growth Fund | 197999 | &nbsp;&nbsp; 38443 | &nbsp;&nbsp; 181510 | &nbsp;&nbsp; 54932 | &nbsp;&nbsp; 5825 | &nbsp;&nbsp; 1144 | &nbsp;&nbsp; 5393 | &nbsp;&nbsp; 1576 |
| Small Cap Value Fund | 88757 | &nbsp;&nbsp; 12106 | &nbsp;&nbsp; 285054 | &nbsp;&nbsp; (184191)<br>| &nbsp;&nbsp; 3123 | &nbsp;&nbsp; 401 | &nbsp;&nbsp; 10232 | &nbsp;&nbsp; (6708)<br>|
| Global Leaders Fund | 1718 | &nbsp;&nbsp; 7662 | &nbsp;&nbsp; 38201 | &nbsp;&nbsp; (28821)<br>| &nbsp;&nbsp; 160 | &nbsp;&nbsp; 1181 | &nbsp;&nbsp; 3412 | &nbsp;&nbsp; (2071)<br>|
| International Leaders Fund | 170554 | &nbsp;&nbsp; 48562 | &nbsp;&nbsp; 204883 | &nbsp;&nbsp; 14233 | &nbsp;&nbsp; 8015 | &nbsp;&nbsp; 2264 | &nbsp;&nbsp; 9602 | &nbsp;&nbsp; 677 |
| International Growth Fund | 118422 | &nbsp;&nbsp; 130989 | &nbsp;&nbsp; 450885 | &nbsp;&nbsp; (201474)<br>| &nbsp;&nbsp; 4137 | &nbsp;&nbsp; 4932 | &nbsp;&nbsp; 15519 | &nbsp;&nbsp; (6450)<br>|
| International Small Cap Growth <br> Fund<br>| 3608 | &nbsp;&nbsp; 444 | &nbsp;&nbsp; 15452 | &nbsp;&nbsp; (11400)<br>| &nbsp;&nbsp; 270 | &nbsp;&nbsp; 32 | &nbsp;&nbsp; 1168 | &nbsp;&nbsp; (866)<br>|
| Emerging Markets Leaders Fund | 3414 | &nbsp;&nbsp; 78 | &nbsp;&nbsp; 7334 | &nbsp;&nbsp; (3842)<br>| &nbsp;&nbsp; 325 | &nbsp;&nbsp; 7 | &nbsp;&nbsp; 700 | &nbsp;&nbsp; (368)<br>|
| Emerging Markets Growth Fund | 106513 | &nbsp;&nbsp; 1249 | &nbsp;&nbsp; 102970 | &nbsp;&nbsp; 4792 | &nbsp;&nbsp; 7624 | &nbsp;&nbsp; 81 | &nbsp;&nbsp; 7536 | &nbsp;&nbsp; 169 |
| Emerging Markets ex China <br> Growth Fund<br>| 4807 | &nbsp;&nbsp; 782 | &nbsp;&nbsp; 2234 | &nbsp;&nbsp; 3355 | &nbsp;&nbsp; 328 | &nbsp;&nbsp; 52 | &nbsp;&nbsp; 167 | &nbsp;&nbsp; 213 |
| Emerging Markets Small Cap <br> Growth Fund<br>| 22341 | &nbsp;&nbsp; 11627 | &nbsp;&nbsp; 54362 | &nbsp;&nbsp; (20394)<br>| &nbsp;&nbsp; 1074 | &nbsp;&nbsp; 540 | &nbsp;&nbsp; 2642 | &nbsp;&nbsp; (1028)<br>|
| China Growth Fund | 6 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 5 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 1 |
| Emerging Markets Debt Fund | 30740 | &nbsp;&nbsp; 1016 | &nbsp;&nbsp; 7229 | &nbsp;&nbsp; 24527 | &nbsp;&nbsp; 3713 | &nbsp;&nbsp; 121 | &nbsp;&nbsp; 866 | &nbsp;&nbsp; 2968 |

---

*December 31, 2025*

**94**

*Annual*

------

**Notes to Financial Statements** 

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $4042 | &nbsp;&nbsp; $8348 | &nbsp;&nbsp; $15025 | &nbsp;&nbsp; $(2635)<br>| &nbsp;&nbsp; 308 | &nbsp;&nbsp; 769 | &nbsp;&nbsp; 1202 | &nbsp;&nbsp; $(125)<br>|
| Large Cap Growth Fund | 88519 | &nbsp;&nbsp; 32350 | &nbsp;&nbsp; 159293 | &nbsp;&nbsp; (38424)<br>| &nbsp;&nbsp; 3009 | &nbsp;&nbsp; 1092 | &nbsp;&nbsp; 5162 | &nbsp;&nbsp; (1061)<br>|
| Mid Cap Value Fund | 0 | &nbsp;&nbsp; 19 | &nbsp;&nbsp; 482 | &nbsp;&nbsp; (463)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; (40)<br>|
| Small-Mid Cap Core Fund | 53531 | &nbsp;&nbsp; 2341 | &nbsp;&nbsp; 23606 | &nbsp;&nbsp; 32266 | &nbsp;&nbsp; 3237 | &nbsp;&nbsp; 140 | &nbsp;&nbsp; 1471 | &nbsp;&nbsp; 1906 |
| Small-Mid Cap Growth Fund | 71628 | &nbsp;&nbsp; 11329 | &nbsp;&nbsp; 233490 | &nbsp;&nbsp; (150533)<br>| &nbsp;&nbsp; 2796 | &nbsp;&nbsp; 413 | &nbsp;&nbsp; 8466 | &nbsp;&nbsp; (5257)<br>|
| Small-Mid Cap Value Fund | 0 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; — | &nbsp;&nbsp; 51 | &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; 5 | &nbsp;&nbsp; — | &nbsp;&nbsp; 4 |
| Small Cap Growth Fund | 118991 | &nbsp;&nbsp; 22934 | &nbsp;&nbsp; 62639 | &nbsp;&nbsp; 79286 | &nbsp;&nbsp; 3404 | &nbsp;&nbsp; 679 | &nbsp;&nbsp; 1851 | &nbsp;&nbsp; 2232 |
| Small Cap Value Fund | 31248 | &nbsp;&nbsp; 8475 | &nbsp;&nbsp; 275227 | &nbsp;&nbsp; (235504)<br>| &nbsp;&nbsp; 1101 | &nbsp;&nbsp; 281 | &nbsp;&nbsp; 9457 | &nbsp;&nbsp; (8075)<br>|
| Global Leaders Fund | 1745 | &nbsp;&nbsp; 1231 | &nbsp;&nbsp; 5796 | &nbsp;&nbsp; (2820)<br>| &nbsp;&nbsp; 152 | &nbsp;&nbsp; 190 | &nbsp;&nbsp; 533 | &nbsp;&nbsp; (191)<br>|
| International Leaders Fund | 14908 | &nbsp;&nbsp; 34098 | &nbsp;&nbsp; 279597 | &nbsp;&nbsp; (230591)<br>| &nbsp;&nbsp; 694 | &nbsp;&nbsp; 1589 | &nbsp;&nbsp; 12917 | &nbsp;&nbsp; (10634)<br>|
| International Growth Fund | 4804 | &nbsp;&nbsp; 13352 | &nbsp;&nbsp; 53728 | &nbsp;&nbsp; (35572)<br>| &nbsp;&nbsp; 170 | &nbsp;&nbsp; 502 | &nbsp;&nbsp; 1927 | &nbsp;&nbsp; (1255)<br>|
| International Small Cap Growth <br> Fund<br>| 2887 | &nbsp;&nbsp; 355 | &nbsp;&nbsp; 45461 | &nbsp;&nbsp; (42219)<br>| &nbsp;&nbsp; 208 | &nbsp;&nbsp; 26 | &nbsp;&nbsp; 3166 | &nbsp;&nbsp; (2932)<br>|
| Emerging Markets Leaders Fund | 4586 | &nbsp;&nbsp; 794 | &nbsp;&nbsp; 102097 | &nbsp;&nbsp; (96717)<br>| &nbsp;&nbsp; 467 | &nbsp;&nbsp; 71 | &nbsp;&nbsp; 9715 | &nbsp;&nbsp; (9177)<br>|
| Emerging Markets Growth Fund | 190596 | &nbsp;&nbsp; 2815 | &nbsp;&nbsp; 274951 | &nbsp;&nbsp; (81540)<br>| &nbsp;&nbsp; 13541 | &nbsp;&nbsp; 181 | &nbsp;&nbsp; 18712 | &nbsp;&nbsp; (4990)<br>|
| Emerging Markets ex China <br> Growth Fund<br>| 10668 | &nbsp;&nbsp; 1938 | &nbsp;&nbsp; 2080 | &nbsp;&nbsp; 10526 | &nbsp;&nbsp; 736 | &nbsp;&nbsp; 128 | &nbsp;&nbsp; 165 | &nbsp;&nbsp; 699 |
| Emerging Markets Small Cap <br> Growth Fund<br>| 18391 | &nbsp;&nbsp; 20834 | &nbsp;&nbsp; 57477 | &nbsp;&nbsp; (18252)<br>| &nbsp;&nbsp; 857 | &nbsp;&nbsp; 964 | &nbsp;&nbsp; 2772 | &nbsp;&nbsp; (951)<br>|
| China Growth Fund | 35 | &nbsp;&nbsp; 17 | &nbsp;&nbsp; 114 | &nbsp;&nbsp; (62)<br>| &nbsp;&nbsp; 5 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 17 | &nbsp;&nbsp; (9)<br>|
| Emerging Markets Debt Fund | 7874 | &nbsp;&nbsp; 1944 | &nbsp;&nbsp; 32634 | &nbsp;&nbsp; (22816)<br>| &nbsp;&nbsp; 953 | &nbsp;&nbsp; 232 | &nbsp;&nbsp; 4023 | &nbsp;&nbsp; (2838)<br>|

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Institutional International Growth <br> Fund<br>| $57536 | &nbsp;&nbsp; $102442 | &nbsp;&nbsp; $274702 | &nbsp;&nbsp; $(114724)<br>| &nbsp;&nbsp; $3965 | &nbsp;&nbsp; $7281 | &nbsp;&nbsp; $18503 | &nbsp;&nbsp; $(7257)<br>|

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $8569 | &nbsp;&nbsp; $50826 | &nbsp;&nbsp; $51082 | &nbsp;&nbsp; $8313 | &nbsp;&nbsp; 687 | &nbsp;&nbsp; 5228 | &nbsp;&nbsp; 4320 | &nbsp;&nbsp; $1595 |
| Large Cap Growth Fund | 405349 | &nbsp;&nbsp; 188267 | &nbsp;&nbsp; 855382 | &nbsp;&nbsp; (261766)<br>| &nbsp;&nbsp; 13697 | &nbsp;&nbsp; 6391 | &nbsp;&nbsp; 28462 | &nbsp;&nbsp; (8374)<br>|
| Mid Cap Value Fund | 1 | &nbsp;&nbsp; 20 | &nbsp;&nbsp; 513 | &nbsp;&nbsp; (492)<br>| &nbsp;&nbsp; 1 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 45 | &nbsp;&nbsp; (42)<br>|
| Small-Mid Cap Core Fund | 68856 | &nbsp;&nbsp; 3478 | &nbsp;&nbsp; 72406 | &nbsp;&nbsp; (72)<br>| &nbsp;&nbsp; 4213 | &nbsp;&nbsp; 208 | &nbsp;&nbsp; 4393 | &nbsp;&nbsp; 28 |
| Small-Mid Cap Growth Fund | 158518 | &nbsp;&nbsp; 34300 | &nbsp;&nbsp; 778839 | &nbsp;&nbsp; (586021)<br>| &nbsp;&nbsp; 6144 | &nbsp;&nbsp; 1262 | &nbsp;&nbsp; 29136 | &nbsp;&nbsp; (21730)<br>|
| Small-Mid Cap Value Fund |  | &nbsp;&nbsp; 54 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 53 | &nbsp;&nbsp; (1)<br>| &nbsp;&nbsp; 5 | &nbsp;&nbsp; — | &nbsp;&nbsp; 4 |
| Small Cap Growth Fund | 330061 | &nbsp;&nbsp; 70789 | &nbsp;&nbsp; 286791 | &nbsp;&nbsp; 114059 | &nbsp;&nbsp; 9709 | &nbsp;&nbsp; 2171 | &nbsp;&nbsp; 8751 | &nbsp;&nbsp; 3129 |
| Small Cap Value Fund | 120096 | &nbsp;&nbsp; 20619 | &nbsp;&nbsp; 560686 | &nbsp;&nbsp; (419971)<br>| &nbsp;&nbsp; 4227 | &nbsp;&nbsp; 683 | &nbsp;&nbsp; 19703 | &nbsp;&nbsp; (14793)<br>|
| Global Leaders Fund | 4069 | &nbsp;&nbsp; 10043 | &nbsp;&nbsp; 46452 | &nbsp;&nbsp; (32340)<br>| &nbsp;&nbsp; 364 | &nbsp;&nbsp; 1554 | &nbsp;&nbsp; 4217 | &nbsp;&nbsp; (2299)<br>|
| International Leaders Fund | 190239 | &nbsp;&nbsp; 84436 | &nbsp;&nbsp; 497064 | &nbsp;&nbsp; (222389)<br>| &nbsp;&nbsp; 8936 | &nbsp;&nbsp; 3936 | &nbsp;&nbsp; 23098 | &nbsp;&nbsp; (10226)<br>|
| International Growth Fund | 129576 | &nbsp;&nbsp; 184071 | &nbsp;&nbsp; 576446 | &nbsp;&nbsp; (262799)<br>| &nbsp;&nbsp; 4531 | &nbsp;&nbsp; 6995 | &nbsp;&nbsp; 20064 | &nbsp;&nbsp; (8538)<br>|
| Institutional International Growth <br> Fund<br>| 57536 | &nbsp;&nbsp; 102442 | &nbsp;&nbsp; 274702 | &nbsp;&nbsp; (114724)<br>| &nbsp;&nbsp; 3965 | &nbsp;&nbsp; 7281 | &nbsp;&nbsp; 18503 | &nbsp;&nbsp; (7257)<br>|
| International Small Cap Growth <br> Fund<br>| 6559 | &nbsp;&nbsp; 803 | &nbsp;&nbsp; 61212 | &nbsp;&nbsp; (53850)<br>| &nbsp;&nbsp; 483 | &nbsp;&nbsp; 58 | &nbsp;&nbsp; 4357 | &nbsp;&nbsp; (3816)<br>|
| Emerging Markets Leaders Fund | 17506 | &nbsp;&nbsp; 879 | &nbsp;&nbsp; 118999 | &nbsp;&nbsp; (100614)<br>| &nbsp;&nbsp; 1674 | &nbsp;&nbsp; 79 | &nbsp;&nbsp; 11299 | &nbsp;&nbsp; (9546)<br>|
| Emerging Markets Growth Fund | 303095 | &nbsp;&nbsp; 4079 | &nbsp;&nbsp; 387586 | &nbsp;&nbsp; (80412)<br>| &nbsp;&nbsp; 21616 | &nbsp;&nbsp; 263 | &nbsp;&nbsp; 26964 | &nbsp;&nbsp; (5085)<br>|
| Emerging Markets ex China <br> Growth Fund<br>| 15475 | &nbsp;&nbsp; 2720 | &nbsp;&nbsp; 4314 | &nbsp;&nbsp; 13881 | &nbsp;&nbsp; 1064 | &nbsp;&nbsp; 180 | &nbsp;&nbsp; 332 | &nbsp;&nbsp; 912 |
| Emerging Markets Small Cap <br> Growth Fund<br>| 42110 | &nbsp;&nbsp; 32793 | &nbsp;&nbsp; 113961 | &nbsp;&nbsp; (39058)<br>| &nbsp;&nbsp; 1996 | &nbsp;&nbsp; 1520 | &nbsp;&nbsp; 5515 | &nbsp;&nbsp; (1999)<br>|
| China Growth Fund | 41 | &nbsp;&nbsp; 18 | &nbsp;&nbsp; 116 | &nbsp;&nbsp; (57)<br>| &nbsp;&nbsp; 6 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 17 | &nbsp;&nbsp; (8)<br>|
| Emerging Markets Debt Fund | 38614 | &nbsp;&nbsp; 2960 | &nbsp;&nbsp; 39863 | &nbsp;&nbsp; 1711 | &nbsp;&nbsp; 4666 | &nbsp;&nbsp; 353 | &nbsp;&nbsp; 4889 | &nbsp;&nbsp; 130 |

---

*December 31, 2025*

**95**

*William Blair Funds*

------

**Notes to Financial Statements** 

The following tables summarize the activity in capital shares of each Fund for the year ended December 31, 2024 (in thousands):

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $1692 | &nbsp;&nbsp; $7988 | &nbsp;&nbsp; $7179 | &nbsp;&nbsp; $2501 | &nbsp;&nbsp; 158 | &nbsp;&nbsp; 906 | &nbsp;&nbsp; 675 | &nbsp;&nbsp; $389 |
| Large Cap Growth Fund | 22102 | &nbsp;&nbsp; 10393 | &nbsp;&nbsp; 42859 | &nbsp;&nbsp; (10364)<br>| &nbsp;&nbsp; 838 | &nbsp;&nbsp; 380 | &nbsp;&nbsp; 1632 | &nbsp;&nbsp; (414)<br>|
| Small-Mid Cap Growth Fund | 6291 | &nbsp;&nbsp; 11193 | &nbsp;&nbsp; 35096 | &nbsp;&nbsp; (17612)<br>| &nbsp;&nbsp; 231 | &nbsp;&nbsp; 446 | &nbsp;&nbsp; 1316 | &nbsp;&nbsp; (639)<br>|
| Small Cap Growth Fund | 13407 | &nbsp;&nbsp; 14930 | &nbsp;&nbsp; 20606 | &nbsp;&nbsp; 7731 | &nbsp;&nbsp; 461 | &nbsp;&nbsp; 522 | &nbsp;&nbsp; 707 | &nbsp;&nbsp; 276 |
| Small Cap Value Fund | 224 | &nbsp;&nbsp; 76 | &nbsp;&nbsp; 639 | &nbsp;&nbsp; (339)<br>| &nbsp;&nbsp; 7 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 21 | &nbsp;&nbsp; (11)<br>|
| Global Leaders Fund | 997 | &nbsp;&nbsp; 1045 | &nbsp;&nbsp; 6069 | &nbsp;&nbsp; (4027)<br>| &nbsp;&nbsp; 61 | &nbsp;&nbsp; 98 | &nbsp;&nbsp; 368 | &nbsp;&nbsp; (209)<br>|
| International Leaders Fund | 3525 | &nbsp;&nbsp; 75 | &nbsp;&nbsp; 10894 | &nbsp;&nbsp; (7294)<br>| &nbsp;&nbsp; 175 | &nbsp;&nbsp; 4 | &nbsp;&nbsp; 540 | &nbsp;&nbsp; (361)<br>|
| International Growth Fund | 5456 | &nbsp;&nbsp; 18262 | &nbsp;&nbsp; 49293 | &nbsp;&nbsp; (25575)<br>| &nbsp;&nbsp; 188 | &nbsp;&nbsp; 692 | &nbsp;&nbsp; 1738 | &nbsp;&nbsp; (858)<br>|
| International Small Cap Growth Fund | 11 | &nbsp;&nbsp; 19 | &nbsp;&nbsp; 240 | &nbsp;&nbsp; (210)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 20 | &nbsp;&nbsp; (18)<br>|
| Emerging Markets Leaders Fund | 8438 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 8620 | &nbsp;&nbsp; (181)<br>| &nbsp;&nbsp; 935 | &nbsp;&nbsp; — | &nbsp;&nbsp; 955 | &nbsp;&nbsp; (20)<br>|
| Emerging Markets Growth Fund | 13082 | &nbsp;&nbsp; — | &nbsp;&nbsp; 12981 | &nbsp;&nbsp; 101 | &nbsp;&nbsp; 1075 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1068 | &nbsp;&nbsp; 7 |
| Emerging Markets Small Cap Growth <br> Fund<br>| 2752 | &nbsp;&nbsp; — | &nbsp;&nbsp; 2926 | &nbsp;&nbsp; (174)<br>| &nbsp;&nbsp; 134 | &nbsp;&nbsp; — | &nbsp;&nbsp; 141 | &nbsp;&nbsp; (7)<br>|

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $6473 | &nbsp;&nbsp; $32153 | &nbsp;&nbsp; $29029 | &nbsp;&nbsp; $9597 | &nbsp;&nbsp; 451 | &nbsp;&nbsp; 2548 | &nbsp;&nbsp; 2030 | &nbsp;&nbsp; $969 |
| Large Cap Growth Fund | 1016607 | &nbsp;&nbsp; 110088 | &nbsp;&nbsp; 460951 | &nbsp;&nbsp; 665744 | &nbsp;&nbsp; 36237 | &nbsp;&nbsp; 3724 | &nbsp;&nbsp; 15997 | &nbsp;&nbsp; 23964 |
| Mid Cap Value Fund | 1 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Small-Mid Cap Core Fund | 29987 | &nbsp;&nbsp; 1252 | &nbsp;&nbsp; 94439 | &nbsp;&nbsp; (63200)<br>| &nbsp;&nbsp; 1900 | &nbsp;&nbsp; 75 | &nbsp;&nbsp; 5677 | &nbsp;&nbsp; (3702)<br>|
| Small-Mid Cap Growth Fund | 163796 | &nbsp;&nbsp; 133580 | &nbsp;&nbsp; 499996 | &nbsp;&nbsp; (202620)<br>| &nbsp;&nbsp; 5494 | &nbsp;&nbsp; 4802 | &nbsp;&nbsp; 16869 | &nbsp;&nbsp; (6573)<br>|
| Small-Mid Cap Value Fund | 1281 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 1239 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 117 | &nbsp;&nbsp; — | &nbsp;&nbsp; 114 | &nbsp;&nbsp; 3 |
| Small Cap Growth Fund | 118867 | &nbsp;&nbsp; 48140 | &nbsp;&nbsp; 133559 | &nbsp;&nbsp; 33448 | &nbsp;&nbsp; 3368 | &nbsp;&nbsp; 1380 | &nbsp;&nbsp; 3840 | &nbsp;&nbsp; 908 |
| Small Cap Value Fund | 120285 | &nbsp;&nbsp; 26992 | &nbsp;&nbsp; 219859 | &nbsp;&nbsp; (72582)<br>| &nbsp;&nbsp; 4026 | &nbsp;&nbsp; 918 | &nbsp;&nbsp; 7241 | &nbsp;&nbsp; (2297)<br>|
| Global Leaders Fund | 1465 | &nbsp;&nbsp; 16680 | &nbsp;&nbsp; 39204 | &nbsp;&nbsp; (21059)<br>| &nbsp;&nbsp; 101 | &nbsp;&nbsp; 1542 | &nbsp;&nbsp; 2474 | &nbsp;&nbsp; (831)<br>|
| International Leaders Fund | 275559 | &nbsp;&nbsp; 3114 | &nbsp;&nbsp; 127247 | &nbsp;&nbsp; 151426 | &nbsp;&nbsp; 13568 | &nbsp;&nbsp; 161 | &nbsp;&nbsp; 6263 | &nbsp;&nbsp; 7466 |
| International Growth Fund | 137229 | &nbsp;&nbsp; 66274 | &nbsp;&nbsp; 165255 | &nbsp;&nbsp; 38248 | &nbsp;&nbsp; 4642 | &nbsp;&nbsp; 2422 | &nbsp;&nbsp; 5631 | &nbsp;&nbsp; 1433 |
| International Small Cap Growth <br> Fund<br>| 8766 | &nbsp;&nbsp; 1285 | &nbsp;&nbsp; 38332 | &nbsp;&nbsp; (28281)<br>| &nbsp;&nbsp; 719 | &nbsp;&nbsp; 105 | &nbsp;&nbsp; 3075 | &nbsp;&nbsp; (2251)<br>|
| Emerging Markets Leaders <br> Fund<br>| 1830 | &nbsp;&nbsp; 27 | &nbsp;&nbsp; 5735 | &nbsp;&nbsp; (3878)<br>| &nbsp;&nbsp; 206 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 632 | &nbsp;&nbsp; (423)<br>|
| Emerging Markets Growth <br> Fund<br>| 120053 | &nbsp;&nbsp; 237 | &nbsp;&nbsp; 58591 | &nbsp;&nbsp; 61699 | &nbsp;&nbsp; 9502 | &nbsp;&nbsp; 18 | &nbsp;&nbsp; 4771 | &nbsp;&nbsp; 4749 |
| Emerging Markets ex China <br> Growth Fund<br>| 6436 | &nbsp;&nbsp; — | &nbsp;&nbsp; 243 | &nbsp;&nbsp; 6193 | &nbsp;&nbsp; 491 | &nbsp;&nbsp; — | &nbsp;&nbsp; 19 | &nbsp;&nbsp; 472 |
| Emerging Markets Small Cap <br> Growth Fund<br>| 48503 | &nbsp;&nbsp; — | &nbsp;&nbsp; 41980 | &nbsp;&nbsp; 6523 | &nbsp;&nbsp; 2336 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1989 | &nbsp;&nbsp; 347 |
| China Growth Fund | 191 | &nbsp;&nbsp; 1 | &nbsp;&nbsp; 289 | &nbsp;&nbsp; (97)<br>| &nbsp;&nbsp; 36 | &nbsp;&nbsp; — | &nbsp;&nbsp; 56 | &nbsp;&nbsp; (20)<br>|
| Emerging Markets Debt Fund | 19094 | &nbsp;&nbsp; 342 | &nbsp;&nbsp; 8748 | &nbsp;&nbsp; 10688 | &nbsp;&nbsp; 2362 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; 1100 | &nbsp;&nbsp; 1304 |

---

*December 31, 2025*

**96**

*Annual*

------

**Notes to Financial Statements** 

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $4611 | &nbsp;&nbsp; $8980 | &nbsp;&nbsp; $14090 | &nbsp;&nbsp; $(499)<br>| &nbsp;&nbsp; 324 | &nbsp;&nbsp; 707 | &nbsp;&nbsp; 959 | &nbsp;&nbsp; $72 |
| Large Cap Growth Fund | 286507 | &nbsp;&nbsp; 23981 | &nbsp;&nbsp; 146085 | &nbsp;&nbsp; 164403 | &nbsp;&nbsp; 9906 | &nbsp;&nbsp; 812 | &nbsp;&nbsp; 5006 | &nbsp;&nbsp; 5712 |
| Mid Cap Value Fund | 131 | &nbsp;&nbsp; 21 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; 150 | &nbsp;&nbsp; 12 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; — | &nbsp;&nbsp; 14 |
| Small-Mid Cap Core Fund | 10741 | &nbsp;&nbsp; 1036 | &nbsp;&nbsp; 40363 | &nbsp;&nbsp; (28586)<br>| &nbsp;&nbsp; 671 | &nbsp;&nbsp; 62 | &nbsp;&nbsp; 2489 | &nbsp;&nbsp; (1756)<br>|
| Small-Mid Cap Growth Fund | 193373 | &nbsp;&nbsp; 61344 | &nbsp;&nbsp; 135020 | &nbsp;&nbsp; 119697 | &nbsp;&nbsp; 6373 | &nbsp;&nbsp; 2196 | &nbsp;&nbsp; 4574 | &nbsp;&nbsp; 3995 |
| Small-Mid Cap Value Fund | 1749 | &nbsp;&nbsp; 60 | &nbsp;&nbsp; 117 | &nbsp;&nbsp; 1692 | &nbsp;&nbsp; 159 | &nbsp;&nbsp; 6 | &nbsp;&nbsp; 11 | &nbsp;&nbsp; 154 |
| Small Cap Growth Fund | 96213 | &nbsp;&nbsp; 23412 | &nbsp;&nbsp; 50540 | &nbsp;&nbsp; 69085 | &nbsp;&nbsp; 2711 | &nbsp;&nbsp; 668 | &nbsp;&nbsp; 1408 | &nbsp;&nbsp; 1971 |
| Small Cap Value Fund | 177269 | &nbsp;&nbsp; 16919 | &nbsp;&nbsp; 66572 | &nbsp;&nbsp; 127616 | &nbsp;&nbsp; 5594 | &nbsp;&nbsp; 576 | &nbsp;&nbsp; 2201 | &nbsp;&nbsp; 3969 |
| Global Leaders Fund | 267 | &nbsp;&nbsp; 4655 | &nbsp;&nbsp; 11047 | &nbsp;&nbsp; (6125)<br>| &nbsp;&nbsp; 16 | &nbsp;&nbsp; 430 | &nbsp;&nbsp; 905 | &nbsp;&nbsp; (459)<br>|
| International Leaders Fund | 38575 | &nbsp;&nbsp; 3225 | &nbsp;&nbsp; 92783 | &nbsp;&nbsp; (50983)<br>| &nbsp;&nbsp; 1898 | &nbsp;&nbsp; 166 | &nbsp;&nbsp; 4609 | &nbsp;&nbsp; (2545)<br>|
| International Growth Fund | 6191 | &nbsp;&nbsp; 7954 | &nbsp;&nbsp; 32167 | &nbsp;&nbsp; (18022)<br>| &nbsp;&nbsp; 212 | &nbsp;&nbsp; 291 | &nbsp;&nbsp; 1086 | &nbsp;&nbsp; (583)<br>|
| International Small Cap Growth <br> Fund<br>| 7967 | &nbsp;&nbsp; 1253 | &nbsp;&nbsp; 60016 | &nbsp;&nbsp; (50796)<br>| &nbsp;&nbsp; 645 | &nbsp;&nbsp; 102 | &nbsp;&nbsp; 4781 | &nbsp;&nbsp; (4034)<br>|
| Emerging Markets Leaders Fund | 7383 | &nbsp;&nbsp; 476 | &nbsp;&nbsp; 106204 | &nbsp;&nbsp; (98345)<br>| &nbsp;&nbsp; 824 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; 11596 | &nbsp;&nbsp; (10721)<br>|
| Emerging Markets Growth Fund | 121666 | &nbsp;&nbsp; 772 | &nbsp;&nbsp; 204453 | &nbsp;&nbsp; (82015)<br>| &nbsp;&nbsp; 9390 | &nbsp;&nbsp; 59 | &nbsp;&nbsp; 16419 | &nbsp;&nbsp; (6970)<br>|
| Emerging Markets ex China <br> Growth Fund<br>| 7969 | &nbsp;&nbsp; — | &nbsp;&nbsp; 3457 | &nbsp;&nbsp; 4512 | &nbsp;&nbsp; 601 | &nbsp;&nbsp; — | &nbsp;&nbsp; 279 | &nbsp;&nbsp; 322 |
| Emerging Markets Small Cap <br> Growth Fund<br>| 21993 | &nbsp;&nbsp; — | &nbsp;&nbsp; 52327 | &nbsp;&nbsp; (30334)<br>| &nbsp;&nbsp; 1045 | &nbsp;&nbsp; — | &nbsp;&nbsp; 2505 | &nbsp;&nbsp; (1460)<br>|
| China Growth Fund | 39 | &nbsp;&nbsp; 24 | &nbsp;&nbsp; 239 | &nbsp;&nbsp; (176)<br>| &nbsp;&nbsp; 8 | &nbsp;&nbsp; 5 | &nbsp;&nbsp; 46 | &nbsp;&nbsp; (33)<br>|
| Emerging Markets Debt Fund | 544 | &nbsp;&nbsp; 3497 | &nbsp;&nbsp; 3064 | &nbsp;&nbsp; 977 | &nbsp;&nbsp; 69 | &nbsp;&nbsp; 436 | &nbsp;&nbsp; 381 | &nbsp;&nbsp; 124 |

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Institutional International Growth Fund | $66691 | &nbsp;&nbsp; $61982 | &nbsp;&nbsp; $121855 | &nbsp;&nbsp; $6818 | &nbsp;&nbsp; $4505 | &nbsp;&nbsp; $4511 | &nbsp;&nbsp; $8176 | &nbsp;&nbsp; $840 |

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** | **Net Change in Net Assets Relating to Fund Share Activity** |
|  | **Dollars** | **Dollars** | **Dollars** | **Dollars** | **Shares** | **Shares** | **Shares** | **Shares** |
| **Fund** | **Sales** | **Reinvest** | **Redemptions** | **Total** | **Sales** | **Reinvest** | **Redemptions** | **Total** |
| Growth Fund | $12776 | &nbsp;&nbsp; $49121 | &nbsp;&nbsp; $50298 | &nbsp;&nbsp; $11599 | &nbsp;&nbsp; 933 | &nbsp;&nbsp; 4161 | &nbsp;&nbsp; 3664 | &nbsp;&nbsp; $1430 |
| Large Cap Growth Fund | 1325216 | &nbsp;&nbsp; 144462 | &nbsp;&nbsp; 649895 | &nbsp;&nbsp; 819783 | &nbsp;&nbsp; 46981 | &nbsp;&nbsp; 4916 | &nbsp;&nbsp; 22635 | &nbsp;&nbsp; 29262 |
| Mid Cap Value Fund | 132 | &nbsp;&nbsp; 22 | &nbsp;&nbsp; 3 | &nbsp;&nbsp; 151 | &nbsp;&nbsp; 12 | &nbsp;&nbsp; 2 | &nbsp;&nbsp; — | &nbsp;&nbsp; 14 |
| Small-Mid Cap Core Fund | 40728 | &nbsp;&nbsp; 2288 | &nbsp;&nbsp; 134802 | &nbsp;&nbsp; (91786)<br>| &nbsp;&nbsp; 2571 | &nbsp;&nbsp; 137 | &nbsp;&nbsp; 8166 | &nbsp;&nbsp; (5458)<br>|
| Small-Mid Cap Growth Fund | 363460 | &nbsp;&nbsp; 206117 | &nbsp;&nbsp; 670112 | &nbsp;&nbsp; (100535)<br>| &nbsp;&nbsp; 12098 | &nbsp;&nbsp; 7444 | &nbsp;&nbsp; 22759 | &nbsp;&nbsp; (3217)<br>|
| Small-Mid Cap Value Fund | 3030 | &nbsp;&nbsp; 62 | &nbsp;&nbsp; 1356 | &nbsp;&nbsp; 1736 | &nbsp;&nbsp; 276 | &nbsp;&nbsp; 6 | &nbsp;&nbsp; 125 | &nbsp;&nbsp; 157 |
| Small Cap Growth Fund | 228487 | &nbsp;&nbsp; 86482 | &nbsp;&nbsp; 204705 | &nbsp;&nbsp; 110264 | &nbsp;&nbsp; 6540 | &nbsp;&nbsp; 2570 | &nbsp;&nbsp; 5955 | &nbsp;&nbsp; 3155 |
| Small Cap Value Fund | 297778 | &nbsp;&nbsp; 43987 | &nbsp;&nbsp; 287070 | &nbsp;&nbsp; 54695 | &nbsp;&nbsp; 9627 | &nbsp;&nbsp; 1497 | &nbsp;&nbsp; 9463 | &nbsp;&nbsp; 1661 |
| Global Leaders Fund | 2729 | &nbsp;&nbsp; 22380 | &nbsp;&nbsp; 56320 | &nbsp;&nbsp; (31211)<br>| &nbsp;&nbsp; 178 | &nbsp;&nbsp; 2070 | &nbsp;&nbsp; 3747 | &nbsp;&nbsp; (1499)<br>|
| International Leaders Fund | 317659 | &nbsp;&nbsp; 6414 | &nbsp;&nbsp; 230924 | &nbsp;&nbsp; 93149 | &nbsp;&nbsp; 15641 | &nbsp;&nbsp; 331 | &nbsp;&nbsp; 11412 | &nbsp;&nbsp; 4560 |
| International Growth Fund | 148876 | &nbsp;&nbsp; 92490 | &nbsp;&nbsp; 246715 | &nbsp;&nbsp; (5349)<br>| &nbsp;&nbsp; 5042 | &nbsp;&nbsp; 3405 | &nbsp;&nbsp; 8455 | &nbsp;&nbsp; (8)<br>|
| Institutional International <br> Growth Fund<br>| 66691 | &nbsp;&nbsp; 61982 | &nbsp;&nbsp; 121855 | &nbsp;&nbsp; 6818 | &nbsp;&nbsp; 4505 | &nbsp;&nbsp; 4511 | &nbsp;&nbsp; 8176 | &nbsp;&nbsp; 840 |
| International Small Cap <br> Growth Fund<br>| 16744 | &nbsp;&nbsp; 2557 | &nbsp;&nbsp; 98588 | &nbsp;&nbsp; (79287)<br>| &nbsp;&nbsp; 1364 | &nbsp;&nbsp; 209 | &nbsp;&nbsp; 7876 | &nbsp;&nbsp; (6303)<br>|
| Emerging Markets Leaders <br> Fund<br>| 17651 | &nbsp;&nbsp; 504 | &nbsp;&nbsp; 120559 | &nbsp;&nbsp; (102404)<br>| &nbsp;&nbsp; 1965 | &nbsp;&nbsp; 54 | &nbsp;&nbsp; 13183 | &nbsp;&nbsp; (11164)<br>|
| Emerging Markets Growth <br> Fund<br>| 254801 | &nbsp;&nbsp; 1009 | &nbsp;&nbsp; 276025 | &nbsp;&nbsp; (20215)<br>| &nbsp;&nbsp; 19967 | &nbsp;&nbsp; 77 | &nbsp;&nbsp; 22258 | &nbsp;&nbsp; (2214)<br>|
| Emerging Markets ex China <br> Growth Fund<br>| 14405 | &nbsp;&nbsp; — | &nbsp;&nbsp; 3700 | &nbsp;&nbsp; 10705 | &nbsp;&nbsp; 1092 | &nbsp;&nbsp; — | &nbsp;&nbsp; 298 | &nbsp;&nbsp; 794 |
| Emerging Markets Small Cap <br> Growth Fund<br>| 73248 | &nbsp;&nbsp; — | &nbsp;&nbsp; 97233 | &nbsp;&nbsp; (23985)<br>| &nbsp;&nbsp; 3515 | &nbsp;&nbsp; — | &nbsp;&nbsp; 4635 | &nbsp;&nbsp; (1120)<br>|
| China Growth Fund | 230 | &nbsp;&nbsp; 25 | &nbsp;&nbsp; 528 | &nbsp;&nbsp; (273)<br>| &nbsp;&nbsp; 44 | &nbsp;&nbsp; 5 | &nbsp;&nbsp; 102 | &nbsp;&nbsp; (53)<br>|
| Emerging Markets Debt Fund | 19638 | &nbsp;&nbsp; 3839 | &nbsp;&nbsp; 11812 | &nbsp;&nbsp; 11665 | &nbsp;&nbsp; 2431 | &nbsp;&nbsp; 478 | &nbsp;&nbsp; 1481 | &nbsp;&nbsp; 1428 |

---

*December 31, 2025*

**97**

*William Blair Funds*

------

**Notes to Financial Statements** 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**(8)** **Recent Accounting Pronouncement**

In this reporting period, the Funds adopted the Financial Accounting Standards Board's Accounting Standards Update No. 2023-09, "*Income Taxes (Topic 740): Improvements to Income Tax Disclosures*" ("ASU 2023-09"). ASU 2023-09 establishes new income tax disclosure requirements and modifies or eliminates certain existing disclosure provisions. The amendments in ASU 2023-09 are intended to address investor requests for more transparency about income tax information and to improve the effectiveness of income tax disclosures. ASU 2023-09 is effective for public entities for annual periods beginning after December 15, 2024, with early adoption permitted. The adoption of ASU 2023-09 only impacts financial statement disclosures and does not impact each Fund's financial position or the results of its operations. For the year ended December 31, 2025, the Adviser has analyzed each Fund's income taxes paid and has determined no additional disclosures are required.

**(9)** **Subsequent Events**

The Funds have evaluated subsequent events through the date of issuance of the Funds' financial statements and have determined there is no impact to the Funds' financial statements.

*December 31, 2025*

**98**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $8.79 | &nbsp;&nbsp; $9.70 | &nbsp;&nbsp; $7.95 | &nbsp;&nbsp; $11.81 | &nbsp;&nbsp; $11.15 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.06)<br>| &nbsp;&nbsp; (0.07)<br>| &nbsp;&nbsp; (0.04)<br>| &nbsp;&nbsp; (0.05)<br>| &nbsp;&nbsp; (0.08)<br>|
| Net realized and unrealized gain (loss) on investments | 0.92 | 2.20 | 3.03 | &nbsp;&nbsp; (3.44)<br>| 2.49 |
| Total from investment operations | 0.86 | 2.13 | 2.99 | &nbsp;&nbsp; (3.49)<br>| 2.41 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 2.95 | 3.04 | 1.24 | 0.37 | 1.75 |
| Total distributions | 2.95 | 3.04 | 1.24 | 0.37 | 1.75 |
| Net asset value, end of period | $6.70 | &nbsp;&nbsp; $8.79 | &nbsp;&nbsp; $9.70 | &nbsp;&nbsp; $7.95 | &nbsp;&nbsp; $11.81 |
| Total return (%) | 10.19 | 21.81 | 37.76 | &nbsp;&nbsp; (29.65)<br>| 22.09 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.25 | 1.23 | 1.26 | 1.24 | 1.21 |
| Expenses, net of waivers and reimbursements | 1.20 | 1.20 | 1.20 | 1.20 | 1.20 |
| Net investment income (loss), before waivers and reimbursements | (0.78)<br>| &nbsp;&nbsp; (0.69)<br>| &nbsp;&nbsp; (0.49)<br>| &nbsp;&nbsp; (0.60)<br>| &nbsp;&nbsp; (0.67)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.73)<br>| &nbsp;&nbsp; (0.66)<br>| &nbsp;&nbsp; (0.43)<br>| &nbsp;&nbsp; (0.56)<br>| &nbsp;&nbsp; (0.66)<br>|
| Class N net assets at the end of the year (in thousands) | $28449 | &nbsp;&nbsp; $31317 | &nbsp;&nbsp; $30789 | &nbsp;&nbsp; $23829 | &nbsp;&nbsp; $36807 |
| Portfolio turnover rate (%) | 62 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 37 | &nbsp;&nbsp; 41 | &nbsp;&nbsp; 30 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.58 | &nbsp;&nbsp; $12.77 | &nbsp;&nbsp; $10.15 | &nbsp;&nbsp; $14.91 | &nbsp;&nbsp; $13.64 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.06)<br>| &nbsp;&nbsp; (0.05)<br>| &nbsp;&nbsp; (0.02)<br>| &nbsp;&nbsp; (0.04)<br>| &nbsp;&nbsp; (0.05)<br>|
| Net realized and unrealized gain (loss) on investments | 1.35 | 2.90 | 3.88 | &nbsp;&nbsp; (4.35)<br>| 3.07 |
| Total from investment operations | 1.29 | 2.85 | 3.86 | &nbsp;&nbsp; (4.39)<br>| 3.02 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 2.95 | 3.04 | 1.24 | 0.37 | 1.75 |
| Total distributions | 2.95 | 3.04 | 1.24 | 0.37 | 1.75 |
| Net asset value, end of period | $10.92 | &nbsp;&nbsp; $12.58 | &nbsp;&nbsp; $12.77 | &nbsp;&nbsp; $10.15 | &nbsp;&nbsp; $14.91 |
| Total return (%) | 10.57 | 22.21 | 38.15 | &nbsp;&nbsp; (29.52)<br>| 22.54 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses | 0.91 | 0.89 | 0.91 | 0.92 | 0.89 |
| Net investment income (loss) | (0.45)<br>| &nbsp;&nbsp; (0.35)<br>| &nbsp;&nbsp; (0.14)<br>| &nbsp;&nbsp; (0.29)<br>| &nbsp;&nbsp; (0.35)<br>|
| Class I net assets at the end of the year (in thousands) | $162350 | &nbsp;&nbsp; $173863 | &nbsp;&nbsp; $164166 | &nbsp;&nbsp; $136051 | &nbsp;&nbsp; $293900 |
| Portfolio turnover rate (%) | 62 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 37 | &nbsp;&nbsp; 41 | &nbsp;&nbsp; 30 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**99**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.66 | &nbsp;&nbsp; $12.84 | &nbsp;&nbsp; $10.19 | &nbsp;&nbsp; $14.95 | &nbsp;&nbsp; $13.67 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.05)<br>| &nbsp;&nbsp; (0.05)<br>| &nbsp;&nbsp; (0.01)<br>| &nbsp;&nbsp; (0.02)<br>| &nbsp;&nbsp; (0.04)<br>|
| Net realized and unrealized gain (loss) on investments | 1.36 | 2.91 | 3.90 | &nbsp;&nbsp; (4.37)<br>| 3.07 |
| Total from investment operations | 1.31 | 2.86 | 3.89 | &nbsp;&nbsp; (4.39)<br>| 3.03 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 2.95 | 3.04 | 1.24 | 0.37 | 1.75 |
| Total distributions | 2.95 | 3.04 | 1.24 | 0.37 | 1.75 |
| Net asset value, end of period | $11.02 | &nbsp;&nbsp; $12.66 | &nbsp;&nbsp; $12.84 | &nbsp;&nbsp; $10.19 | &nbsp;&nbsp; $14.95 |
| Total return (%) | 10.66 | 22.26 | 38.19 | &nbsp;&nbsp; (29.44)<br>| 22.55 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses | 0.87 | 0.85 | 0.87 | 0.87 | 0.84 |
| Net investment income (loss) | (0.41)<br>| &nbsp;&nbsp; (0.32)<br>| &nbsp;&nbsp; (0.10)<br>| &nbsp;&nbsp; (0.18)<br>| &nbsp;&nbsp; (0.29)<br>|
| Class R6 net assets at the end of the year (in thousands) | $37566 | &nbsp;&nbsp; $44736 | &nbsp;&nbsp; $44437 | &nbsp;&nbsp; $29128 | &nbsp;&nbsp; $14993 |
| Portfolio turnover rate (%) | 62 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 37 | &nbsp;&nbsp; 41 | &nbsp;&nbsp; 30 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**100**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Large Cap Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $27.15 | &nbsp;&nbsp; $22.95 | &nbsp;&nbsp; $16.38 | &nbsp;&nbsp; $24.49 | &nbsp;&nbsp; $20.03 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.12)<br>| &nbsp;&nbsp; (0.10)<br>| &nbsp;&nbsp; (0.02)<br>| &nbsp;&nbsp; (0.03)<br>| &nbsp;&nbsp; (0.07)<br>|
| Net realized and unrealized gain (loss) on investments | 3.16 | 6.03 | 6.59 | &nbsp;&nbsp; (7.96)<br>| 5.65 |
| Total from investment operations | 3.04 | 5.93 | 6.57 | &nbsp;&nbsp; (7.99)<br>| 5.58 |
| Less distributions from: |  |  |  |  |  |
| Net investment income |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain | 2.58 | 1.73 | &nbsp;&nbsp; — | 0.12 | 1.12 |
| Total distributions | 2.58 | 1.73 | &nbsp;&nbsp; — | 0.12 | 1.12 |
| Net asset value, end of period | $27.61 | &nbsp;&nbsp; $27.15 | &nbsp;&nbsp; $22.95 | &nbsp;&nbsp; $16.38 | &nbsp;&nbsp; $24.49 |
| Total return (%) | 11.36 | 25.79 | 40.11 | &nbsp;&nbsp; (32.61)<br>| 28.03 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.02 | 1.03 | 1.04 | 1.03 | 1.05 |
| Expenses, net of waivers and reimbursements | 0.90 | 0.90 | 0.90 | 0.90 | 0.90 |
| Net investment income (loss), before waivers and reimbursements | (0.56)<br>| &nbsp;&nbsp; (0.50)<br>| &nbsp;&nbsp; (0.24)<br>| &nbsp;&nbsp; (0.28)<br>| &nbsp;&nbsp; (0.46)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.44)<br>| &nbsp;&nbsp; (0.37)<br>| &nbsp;&nbsp; (0.10)<br>| &nbsp;&nbsp; (0.15)<br>| &nbsp;&nbsp; (0.31)<br>|
| Class N net assets at the end of the year (in thousands) | $132535 | &nbsp;&nbsp; $176066 | &nbsp;&nbsp; $158351 | &nbsp;&nbsp; $132225 | &nbsp;&nbsp; $203014 |
| Portfolio turnover rate (%) | 41 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 43 | &nbsp;&nbsp; 29 | &nbsp;&nbsp; 26 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $29.33 | &nbsp;&nbsp; $24.64 | &nbsp;&nbsp; $17.54 | &nbsp;&nbsp; $26.18 | &nbsp;&nbsp; $21.29 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.06)<br>| &nbsp;&nbsp; (0.03)<br>| 0.03 | 0.03 | &nbsp;&nbsp; (0.02)<br>|
| Net realized and unrealized gain (loss) on investments | 3.44 | 6.47 | 7.07 | &nbsp;&nbsp; (8.53)<br>| 6.03 |
| Total from investment operations | 3.38 | 6.44 | 7.10 | &nbsp;&nbsp; (8.50)<br>| 6.01 |
| Less distributions from: |  |  |  |  |  |
| Net investment income |  | 0.02 | &nbsp;&nbsp; — | 0.02 | &nbsp;&nbsp; — |
| Net realized gain | 2.58 | 1.73 | &nbsp;&nbsp; — | 0.12 | 1.12 |
| Total distributions | 2.58 | 1.75 | &nbsp;&nbsp; — | 0.14 | 1.12 |
| Net asset value, end of period | $30.13 | &nbsp;&nbsp; $29.33 | &nbsp;&nbsp; $24.64 | &nbsp;&nbsp; $17.54 | &nbsp;&nbsp; $26.18 |
| Total return (%) | 11.68 | 26.08 | 40.48 | &nbsp;&nbsp; (32.46)<br>| 28.39 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 0.75 | 0.75 | 0.78 | 0.79 | 0.75 |
| Expenses, net of waivers and reimbursements | 0.65 | 0.65 | 0.65 | 0.65 | 0.65 |
| Net investment income (loss), before waivers and reimbursements | (0.29)<br>| &nbsp;&nbsp; (0.22)<br>| 0.02 | &nbsp;&nbsp; (0.01)<br>| &nbsp;&nbsp; (0.17)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.19)<br>| &nbsp;&nbsp; (0.12)<br>| 0.15 | 0.13 | &nbsp;&nbsp; (0.07)<br>|
| Class I net assets at the end of the year (in thousands) | $1905753 | &nbsp;&nbsp; $2020494 | &nbsp;&nbsp; $1106857 | &nbsp;&nbsp; $702441 | &nbsp;&nbsp; $669060 |
| Portfolio turnover rate (%) | 41 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 43 | &nbsp;&nbsp; 29 | &nbsp;&nbsp; 26 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**101**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Large Cap Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $29.33 | &nbsp;&nbsp; $24.64 | &nbsp;&nbsp; $17.53 | &nbsp;&nbsp; $26.16 | &nbsp;&nbsp; $21.27 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.04)<br>| &nbsp;&nbsp; (0.02)<br>| 0.04 | 0.04 | &nbsp;&nbsp; (0.00 )<sup>^</sup><br>|
| Net realized and unrealized gain (loss) on investments | 3.43 | 6.47 | 7.07 | &nbsp;&nbsp; (8.52)<br>| 6.01 |
| Total from investment operations | 3.39 | 6.45 | 7.11 | &nbsp;&nbsp; (8.48)<br>| 6.01 |
| Less distributions from: |  |  |  |  |  |
| Net investment income |  | 0.03 | &nbsp;&nbsp; — | 0.03 | 0.00 <br><sup>^</sup><br>|
| Net realized gain | 2.58 | 1.73 | &nbsp;&nbsp; — | 0.12 | 1.12 |
| Total distributions | 2.58 | 1.76 | &nbsp;&nbsp; — | 0.15 | 1.12 |
| Net asset value, end of period | $30.14 | &nbsp;&nbsp; $29.33 | &nbsp;&nbsp; $24.64 | &nbsp;&nbsp; $17.53 | &nbsp;&nbsp; $26.16 |
| Total return (%) | 11.71 | 26.14 | 40.56 | &nbsp;&nbsp; (32.41)<br>| 28.42 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 0.64 | 0.65 | 0.65 | 0.66 | 0.67 |
| Expenses, net of waivers and reimbursements | 0.60 | 0.60 | 0.60 | 0.60 | 0.60 |
| Net investment income (loss), before waivers and reimbursements | (0.18)<br>| &nbsp;&nbsp; (0.12)<br>| 0.14 | 0.13 | &nbsp;&nbsp; (0.08)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.14)<br>| &nbsp;&nbsp; (0.07)<br>| 0.19 | 0.19 | &nbsp;&nbsp; (0.01)<br>|
| Class R6 net assets at the end of the year (in thousands) | $591441 | &nbsp;&nbsp; $606663 | &nbsp;&nbsp; $368894 | &nbsp;&nbsp; $238354 | &nbsp;&nbsp; $233946 |
| Portfolio turnover rate (%) | 41 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 43 | &nbsp;&nbsp; 29 | &nbsp;&nbsp; 26 |

---

------

---

| | |
|:---|:---|
| ^ | Amount is less than $0.005 per share. |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**102**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Mid Cap Value Fund**

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $11.21 | &nbsp;&nbsp; $10.25 | &nbsp;&nbsp; $9.19 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |
| Net investment income (loss) | 0.11 | 0.14 | 0.14 | 0.12 |
| Net realized and unrealized gain (loss) on investments | 0.71 | 0.96 | 1.07 | &nbsp;&nbsp; (0.83)<br>|
| Total from investment operations | 0.82 | 1.10 | 1.21 | &nbsp;&nbsp; (0.71)<br>|
| Less distributions from: |  |  |  |  |
| Net investment income | 0.14 | 0.14 | 0.15 | 0.10 |
| Net realized gain | 0.03 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total distributions | 0.17 | 0.14 | 0.15 | 0.10 |
| Net asset value, end of period | $11.86 | &nbsp;&nbsp; $11.21 | &nbsp;&nbsp; $10.25 | &nbsp;&nbsp; $9.19 |
| Total return (%)\* | 7.33 | 10.71 | 13.21 | &nbsp;&nbsp; (7.13)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |
| Expenses, before waivers and reimbursements | 9.25 | 8.77 | 9.08 | 8.52 |
| Expenses, net of waivers and reimbursements | 0.75 | 0.75 | 0.75 | 0.75 |
| Net investment income (loss), before waivers and reimbursements | (7.50)<br>| &nbsp;&nbsp; (6.75)<br>| &nbsp;&nbsp; (6.85)<br>| &nbsp;&nbsp; (6.14)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.00 | 1.27 | 1.48 | 1.63 |
| Class I net assets at the end of the year (in thousands) | $70 | &nbsp;&nbsp; $95 | &nbsp;&nbsp; $85 | &nbsp;&nbsp; $76 |
| Portfolio turnover rate (%)\* | 28 | &nbsp;&nbsp; 39 | &nbsp;&nbsp; 32 | &nbsp;&nbsp; 21 |

---

------

(a) For the period from March 16, 2022 (Commencement of Operations) to December 31, 2022. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $11.21 | &nbsp;&nbsp; $10.25 | &nbsp;&nbsp; $9.19 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |
| Net investment income (loss) | 0.12 | 0.14 | 0.14 | 0.11 |
| Net realized and unrealized gain (loss) on investments | 0.71 | 0.96 | 1.08 | &nbsp;&nbsp; (0.82)<br>|
| Total from investment operations | 0.83 | 1.10 | 1.22 | &nbsp;&nbsp; (0.71)<br>|
| Less distributions from: |  |  |  |  |
| Net investment income | 0.15 | 0.14 | 0.16 | 0.10 |
| Net realized gain | 0.03 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total distributions | 0.18 | 0.14 | 0.16 | 0.10 |
| Net asset value, end of period | $11.86 | &nbsp;&nbsp; $11.21 | &nbsp;&nbsp; $10.25 | &nbsp;&nbsp; $9.19 |
| Total return (%)\* | 7.39 | 10.77 | 13.14 | &nbsp;&nbsp; (7.01)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |
| Expenses, before waivers and reimbursements | 9.22 | 8.72 | 9.02 | 8.52 |
| Expenses, net of waivers and reimbursements | 0.70 | 0.70 | 0.70 | 0.70 |
| Net investment income (loss), before waivers and reimbursements | (7.43)<br>| &nbsp;&nbsp; (6.69)<br>| &nbsp;&nbsp; (6.82)<br>| &nbsp;&nbsp; (6.35)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.09 | 1.33 | 1.50 | 1.47 |
| Class R6 net assets at the end of the year (in thousands) | $1283 | &nbsp;&nbsp; $1662 | &nbsp;&nbsp; $1373 | &nbsp;&nbsp; $1431 |
| Portfolio turnover rate (%)\* | 28 | &nbsp;&nbsp; 39 | &nbsp;&nbsp; 32 | &nbsp;&nbsp; 21 |

---

------

(a) For the period from March 16, 2022 (Commencement of Operations) to December 31, 2022. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**103**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Mid Cap Value Fund (continued)**

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**104**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small-Mid Cap Core Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $16.91 | &nbsp;&nbsp; $15.29 | &nbsp;&nbsp; $13.52 | &nbsp;&nbsp; $16.31 | &nbsp;&nbsp; $12.88 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.02 | 0.02 | 0.04 | &nbsp;&nbsp; (0.01)<br>| &nbsp;&nbsp; (0.03)<br>|
| Net realized and unrealized gain (loss) on investments | 0.20 | 1.83 | 1.75 | &nbsp;&nbsp; (2.78)<br>| 3.46 |
| Total from investment operations | 0.22 | 1.85 | 1.79 | &nbsp;&nbsp; (2.79)<br>| 3.43 |
| Less distributions from: |  |  |  |  |  |
| Net investment income |  | 0.02 | 0.02 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain | 0.50 | 0.21 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total distributions | 0.50 | 0.23 | 0.02 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net asset value, end of period | $16.63 | &nbsp;&nbsp; $16.91 | &nbsp;&nbsp; $15.29 | &nbsp;&nbsp; $13.52 | &nbsp;&nbsp; $16.31 |
| Total return (%) | 1.27 | 12.04 | 13.26 | &nbsp;&nbsp; (17.11)<br>| 26.63 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.19 | 1.15 | 1.16 | 1.21 | 1.25 |
| Expenses, net of waivers and reimbursements | 0.95 | 0.95 | 0.95 | 0.95 | 0.95 |
| Net investment income (loss), before waivers and reimbursements | (0.11)<br>| &nbsp;&nbsp; (0.06)<br>| 0.09 | &nbsp;&nbsp; (0.32)<br>| &nbsp;&nbsp; (0.47)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.13 | 0.14 | 0.30 | &nbsp;&nbsp; (0.06)<br>| &nbsp;&nbsp; (0.17)<br>|
| Class I net assets at the end of the year (in thousands) | $18138 | &nbsp;&nbsp; $50188 | &nbsp;&nbsp; $101972 | &nbsp;&nbsp; $87540 | &nbsp;&nbsp; $61433 |
| Portfolio turnover rate (%) | 81 | &nbsp;&nbsp; 59 | &nbsp;&nbsp; 41 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 45 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $16.92 | &nbsp;&nbsp; $15.30 | &nbsp;&nbsp; $13.53 | &nbsp;&nbsp; $16.32 | &nbsp;&nbsp; $12.88 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.03 | 0.03 | 0.05 | 0.00 <br><sup>^</sup><br>| &nbsp;&nbsp; (0.02)<br>|
| Net realized and unrealized gain (loss) on investments | 0.20 | 1.83 | 1.75 | &nbsp;&nbsp; (2.79)<br>| 3.46 |
| Total from investment operations | 0.23 | 1.86 | 1.80 | &nbsp;&nbsp; (2.79)<br>| 3.44 |
| Less distributions from: |  |  |  |  |  |
| Net investment income |  | 0.03 | 0.03 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain | 0.50 | 0.21 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total distributions | 0.50 | 0.24 | 0.03 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net asset value, end of period | $16.65 | &nbsp;&nbsp; $16.92 | &nbsp;&nbsp; $15.30 | &nbsp;&nbsp; $13.53 | &nbsp;&nbsp; $16.32 |
| Total return (%) | 1.33 | 12.16 | 13.30 | &nbsp;&nbsp; (17.10)<br>| 26.71 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.04 | 1.01 | 1.01 | 1.05 | 1.16 |
| Expenses, net of waivers and reimbursements | 0.90 | 0.90 | 0.90 | 0.90 | 0.90 |
| Net investment income (loss), before waivers and reimbursements | 0.03 | 0.07 | 0.24 | &nbsp;&nbsp; (0.14)<br>| &nbsp;&nbsp; (0.37)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.17 | 0.18 | 0.35 | 0.01 | &nbsp;&nbsp; (0.11)<br>|
| Class R6 net assets at the end of the year (in thousands) | $104991 | &nbsp;&nbsp; $74463 | &nbsp;&nbsp; $94208 | &nbsp;&nbsp; $56681 | &nbsp;&nbsp; $31347 |
| Portfolio turnover rate (%) | 81 | &nbsp;&nbsp; 59 | &nbsp;&nbsp; 41 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 45 |

---

------

---

| | |
|:---|:---|
| ^ | Amount is less than $0.005 per share. |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**105**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small-Mid Cap Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $25.31 | &nbsp;&nbsp; $25.92 | &nbsp;&nbsp; $23.96 | &nbsp;&nbsp; $32.27 | &nbsp;&nbsp; $32.96 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.17)<br>| &nbsp;&nbsp; (0.19)<br>| &nbsp;&nbsp; (0.16)<br>| &nbsp;&nbsp; (0.23)<br>| &nbsp;&nbsp; (0.36)<br>|
| Net realized and unrealized gain (loss) on investments | 0.26 | 3.07 | 4.35 | &nbsp;&nbsp; (7.22)<br>| 2.90 |
| Total from investment operations | 0.09 | 2.88 | 4.19 | &nbsp;&nbsp; (7.45)<br>| 2.54 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 0.77 | 3.49 | 2.23 | 0.86 | 3.23 |
| Total distributions | 0.77 | 3.49 | 2.23 | 0.86 | 3.23 |
| Net asset value, end of period | $24.63 | &nbsp;&nbsp; $25.31 | &nbsp;&nbsp; $25.92 | &nbsp;&nbsp; $23.96 | &nbsp;&nbsp; $32.27 |
| Total return (%) | 0.37 | 11.21 | 17.64 | &nbsp;&nbsp; (23.11)<br>| 8.27 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.37 | 1.36 | 1.39 | 1.43 | 1.43 |
| Expenses, net of waivers and reimbursements | 1.24 | 1.24 | 1.28 | 1.35 | 1.35 |
| Net investment income (loss), before waivers and reimbursements | (0.85)<br>| &nbsp;&nbsp; (0.80)<br>| &nbsp;&nbsp; (0.72)<br>| &nbsp;&nbsp; (0.96)<br>| &nbsp;&nbsp; (1.10)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.72)<br>| &nbsp;&nbsp; (0.68)<br>| &nbsp;&nbsp; (0.61)<br>| &nbsp;&nbsp; (0.88)<br>| &nbsp;&nbsp; (1.02)<br>|
| Class N net assets at the end of the year (in thousands) | $62475 | &nbsp;&nbsp; $89046 | &nbsp;&nbsp; $107791 | &nbsp;&nbsp; $110241 | &nbsp;&nbsp; $232166 |
| Portfolio turnover rate (%) | 57 | &nbsp;&nbsp; 63 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 38 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $28.03 | &nbsp;&nbsp; $28.29 | &nbsp;&nbsp; $25.91 | &nbsp;&nbsp; $34.72 | &nbsp;&nbsp; $35.13 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.13)<br>| &nbsp;&nbsp; (0.13)<br>| &nbsp;&nbsp; (0.10)<br>| &nbsp;&nbsp; (0.18)<br>| &nbsp;&nbsp; (0.29)<br>|
| Net realized and unrealized gain (loss) on investments | 0.30 | 3.36 | 4.71 | &nbsp;&nbsp; (7.77)<br>| 3.11 |
| Total from investment operations | 0.17 | 3.23 | 4.61 | &nbsp;&nbsp; (7.95)<br>| 2.82 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 0.77 | 3.49 | 2.23 | 0.86 | 3.23 |
| Total distributions | 0.77 | 3.49 | 2.23 | 0.86 | 3.23 |
| Net asset value, end of period | $27.43 | &nbsp;&nbsp; $28.03 | &nbsp;&nbsp; $28.29 | &nbsp;&nbsp; $25.91 | &nbsp;&nbsp; $34.72 |
| Total return (%) | 0.62 | 11.51 | 17.93 | &nbsp;&nbsp; (22.92)<br>| 8.56 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.12 | 1.11 | 1.14 | 1.17 | 1.16 |
| Expenses, net of waivers and reimbursements | 0.99 | 0.99 | 1.03 | 1.10 | 1.10 |
| Net investment income (loss), before waivers and reimbursements | (0.60)<br>| &nbsp;&nbsp; (0.55)<br>| &nbsp;&nbsp; (0.47)<br>| &nbsp;&nbsp; (0.70)<br>| &nbsp;&nbsp; (0.83)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.47)<br>| &nbsp;&nbsp; (0.43)<br>| &nbsp;&nbsp; (0.36)<br>| &nbsp;&nbsp; (0.63)<br>| &nbsp;&nbsp; (0.77)<br>|
| Class I net assets at the end of the year (in thousands) | $788511 | &nbsp;&nbsp; $1239788 | &nbsp;&nbsp; $1437622 | &nbsp;&nbsp; $1509931 | &nbsp;&nbsp; $2487862 |
| Portfolio turnover rate (%) | 57 | &nbsp;&nbsp; 63 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 38 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**106**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small-Mid Cap Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $28.15 | &nbsp;&nbsp; $28.39 | &nbsp;&nbsp; $25.99 | &nbsp;&nbsp; $34.79 | &nbsp;&nbsp; $35.18 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.11)<br>| &nbsp;&nbsp; (0.11)<br>| &nbsp;&nbsp; (0.09)<br>| &nbsp;&nbsp; (0.15)<br>| &nbsp;&nbsp; (0.26)<br>|
| Net realized and unrealized gain (loss) on investments | 0.30 | 3.36 | 4.72 | &nbsp;&nbsp; (7.79)<br>| 3.10 |
| Total from investment operations | 0.19 | 3.25 | 4.63 | &nbsp;&nbsp; (7.94)<br>| 2.84 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 0.77 | 3.49 | 2.23 | 0.86 | 3.23 |
| Total distributions | 0.77 | 3.49 | 2.23 | 0.86 | 3.23 |
| Net asset value, end of period | $27.57 | &nbsp;&nbsp; $28.15 | &nbsp;&nbsp; $28.39 | &nbsp;&nbsp; $25.99 | &nbsp;&nbsp; $34.79 |
| Total return (%) | 0.69 | 11.54 | 17.95 | &nbsp;&nbsp; (22.84)<br>| 8.60 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 0.99 | 0.98 | 1.01 | 1.05 | 1.03 |
| Expenses, net of waivers and reimbursements | 0.94 | 0.94 | 0.97 | 1.05 | 1.03 |
| Net investment income (loss), before waivers and reimbursements | (0.47)<br>| &nbsp;&nbsp; (0.41)<br>| &nbsp;&nbsp; (0.36)<br>| &nbsp;&nbsp; (0.55)<br>| &nbsp;&nbsp; (0.69)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.42)<br>| &nbsp;&nbsp; (0.37)<br>| &nbsp;&nbsp; (0.32)<br>| &nbsp;&nbsp; (0.55)<br>| &nbsp;&nbsp; (0.69)<br>|
| Class R6 net assets at the end of the year (in thousands) | $401965 | &nbsp;&nbsp; $558398 | &nbsp;&nbsp; $449782 | &nbsp;&nbsp; $392153 | &nbsp;&nbsp; $328034 |
| Portfolio turnover rate (%) | 57 | &nbsp;&nbsp; 63 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 38 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**107**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small-Mid Cap Value Fund**

---

| | | | |
|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $10.97 | &nbsp;&nbsp; $10.60 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |
| Net investment income (loss) | 0.11 | 0.16 | 0.05 |
| Net realized and unrealized gain (loss) on investments | 0.24 | 0.41 | 0.60 |
| Total from investment operations | 0.35 | 0.57 | 0.65 |
| Less distributions from: |  |  |  |
| Net investment income | 0.10 | 0.10 | 0.05 |
| Net realized gain | 0.07 | 0.10 | &nbsp;&nbsp; — |
| Total distributions | 0.17 | 0.20 | 0.05 |
| Net asset value, end of period | $11.15 | &nbsp;&nbsp; $10.97 | &nbsp;&nbsp; $10.60 |
| Total return (%)\* | 3.16 | 5.39 | 6.45 |
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |
| Expenses, before waivers and reimbursements | 5.04 | 5.98 | 10.69 |
| Expenses, net of waivers and reimbursements | 0.85 | 0.85 | 0.85 |
| Net investment income (loss), before waivers and reimbursements | (3.18)<br>| &nbsp;&nbsp; (3.67)<br>| &nbsp;&nbsp; (8.48)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.01 | 1.46 | 1.36 |
| Class I net assets at the end of the year (in thousands) | $124 | &nbsp;&nbsp; $121 | &nbsp;&nbsp; $84 |
| Portfolio turnover rate (%)\* | 40 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 33 |

---

------

(a) For the period from August 17, 2023 (Commencement of Operations) to December 31, 2023. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

---

| | | | |
|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $10.96 | &nbsp;&nbsp; $10.60 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |
| Net investment income (loss) | 0.11 | 0.14 | 0.05 |
| Net realized and unrealized gain (loss) on investments | 0.25 | 0.43 | 0.60 |
| Total from investment operations | 0.36 | 0.57 | 0.65 |
| Less distributions from: |  |  |  |
| Net investment income | 0.11 | 0.11 | 0.05 |
| Net realized gain | 0.07 | 0.10 | &nbsp;&nbsp; — |
| Total distributions | 0.18 | 0.21 | 0.05 |
| Net asset value, end of period | $11.14 | &nbsp;&nbsp; $10.96 | &nbsp;&nbsp; $10.60 |
| Total return (%)\* | 3.21 | 5.37 | 6.50 |
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |
| Expenses, before waivers and reimbursements | 4.99 | 5.95 | 10.66 |
| Expenses, net of waivers and reimbursements | 0.80 | 0.80 | 0.80 |
| Net investment income (loss), before waivers and reimbursements | (3.13)<br>| &nbsp;&nbsp; (3.90)<br>| &nbsp;&nbsp; (8.49)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.06 | 1.25 | 1.37 |
| Class R6 net assets at the end of the year (in thousands) | $3333 | &nbsp;&nbsp; $3229 | &nbsp;&nbsp; $1497 |
| Portfolio turnover rate (%)\* | 40 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 33 |

---

------

(a) For the period from August 17, 2023 (Commencement of Operations) to December 31, 2023. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**108**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small-Mid Cap Value Fund (continued)**

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**109**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small Cap Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $28.97 | &nbsp;&nbsp; $27.36 | &nbsp;&nbsp; $24.01 | &nbsp;&nbsp; $31.90 | &nbsp;&nbsp; $34.49 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.17)<br>| &nbsp;&nbsp; (0.21)<br>| &nbsp;&nbsp; (0.18)<br>| &nbsp;&nbsp; (0.27)<br>| &nbsp;&nbsp; (0.45)<br>|
| Net realized and unrealized gain (loss) on investments | 0.95 | 5.38 | 4.03 | &nbsp;&nbsp; (6.61)<br>| 4.56 |
| Total from investment operations | 0.78 | 5.17 | 3.85 | &nbsp;&nbsp; (6.88)<br>| 4.11 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 2.54 | 3.56 | 0.50 | 1.01 | 6.70 |
| Total distributions | 2.54 | 3.56 | 0.50 | 1.01 | 6.70 |
| Net asset value, end of period | $27.21 | &nbsp;&nbsp; $28.97 | &nbsp;&nbsp; $27.36 | &nbsp;&nbsp; $24.01 | &nbsp;&nbsp; $31.90 |
| Total return (%) | 2.74 | 19.07 | 16.06 | &nbsp;&nbsp; (21.59)<br>| 12.91 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.39 | 1.39 | 1.46 | 1.55 | 1.56 |
| Expenses, net of waivers and reimbursements | 1.24 | 1.24 | 1.33 | 1.50 | 1.50 |
| Net investment income (loss), before waivers and reimbursements | (0.78)<br>| &nbsp;&nbsp; (0.85)<br>| &nbsp;&nbsp; (0.83)<br>| &nbsp;&nbsp; (1.08)<br>| &nbsp;&nbsp; (1.24)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.63)<br>| &nbsp;&nbsp; (0.70)<br>| &nbsp;&nbsp; (0.70)<br>| &nbsp;&nbsp; (1.03)<br>| &nbsp;&nbsp; (1.18)<br>|
| Class N net assets at the end of the year (in thousands) | $110716 | &nbsp;&nbsp; $137552 | &nbsp;&nbsp; $122370 | &nbsp;&nbsp; $114324 | &nbsp;&nbsp; $179739 |
| Portfolio turnover rate (%) | 94 | &nbsp;&nbsp; 75 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 45 | &nbsp;&nbsp; 49 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $35.35 | &nbsp;&nbsp; $32.64 | &nbsp;&nbsp; $28.49 | &nbsp;&nbsp; $37.52 | &nbsp;&nbsp; $39.36 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.13)<br>| &nbsp;&nbsp; (0.16)<br>| &nbsp;&nbsp; (0.13)<br>| &nbsp;&nbsp; (0.24)<br>| &nbsp;&nbsp; (0.41)<br>|
| Net realized and unrealized gain (loss) on investments | 1.18 | 6.43 | 4.78 | &nbsp;&nbsp; (7.78)<br>| 5.27 |
| Total from investment operations | 1.05 | 6.27 | 4.65 | &nbsp;&nbsp; (8.02)<br>| 4.86 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 2.54 | 3.56 | 0.50 | 1.01 | 6.70 |
| Total distributions | 2.54 | 3.56 | 0.50 | 1.01 | 6.70 |
| Net asset value, end of period | $33.86 | &nbsp;&nbsp; $35.35 | &nbsp;&nbsp; $32.64 | &nbsp;&nbsp; $28.49 | &nbsp;&nbsp; $37.52 |
| Total return (%) | 3.01 | 19.36 | 16.35 | &nbsp;&nbsp; (21.39)<br>| 13.22 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.12 | 1.12 | 1.18 | 1.28 | 1.25 |
| Expenses, net of waivers and reimbursements | 0.99 | 0.99 | 1.07 | 1.25 | 1.25 |
| Net investment income (loss), before waivers and reimbursements | (0.50)<br>| &nbsp;&nbsp; (0.58)<br>| &nbsp;&nbsp; (0.54)<br>| &nbsp;&nbsp; (0.81)<br>| &nbsp;&nbsp; (0.93)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.37)<br>| &nbsp;&nbsp; (0.45)<br>| &nbsp;&nbsp; (0.43)<br>| &nbsp;&nbsp; (0.78)<br>| &nbsp;&nbsp; (0.93)<br>|
| Class I net assets at the end of the year (in thousands) | $546225 | &nbsp;&nbsp; $514625 | &nbsp;&nbsp; $445483 | &nbsp;&nbsp; $303016 | &nbsp;&nbsp; $402629 |
| Portfolio turnover rate (%) | 94 | &nbsp;&nbsp; 75 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 45 | &nbsp;&nbsp; 49 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**110**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small Cap Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $35.51 | &nbsp;&nbsp; $32.76 | &nbsp;&nbsp; $28.57 | &nbsp;&nbsp; $37.60 | &nbsp;&nbsp; $39.40 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.11)<br>| &nbsp;&nbsp; (0.14)<br>| &nbsp;&nbsp; (0.12)<br>| &nbsp;&nbsp; (0.21)<br>| &nbsp;&nbsp; (0.37)<br>|
| Net realized and unrealized gain (loss) on investments | 1.18 | 6.45 | 4.81 | &nbsp;&nbsp; (7.81)<br>| 5.27 |
| Total from investment operations | 1.07 | 6.31 | 4.69 | &nbsp;&nbsp; (8.02)<br>| 4.90 |
| Less distributions from: |  |  |  |  |  |
| Net realized gain | 2.54 | 3.56 | 0.50 | 1.01 | 6.70 |
| Total distributions | 2.54 | 3.56 | 0.50 | 1.01 | 6.70 |
| Net asset value, end of period | $34.04 | &nbsp;&nbsp; $35.51 | &nbsp;&nbsp; $32.76 | &nbsp;&nbsp; $28.57 | &nbsp;&nbsp; $37.60 |
| Total return (%) | 3.05 | 19.41 | 16.44 | &nbsp;&nbsp; (21.35)<br>| 13.31 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.01 | 1.00 | 1.06 | 1.18 | 1.16 |
| Expenses, net of waivers and reimbursements | 0.94 | 0.94 | 1.02 | 1.18 | 1.16 |
| Net investment income (loss), before waivers and reimbursements | (0.39)<br>| &nbsp;&nbsp; (0.46)<br>| &nbsp;&nbsp; (0.42)<br>| &nbsp;&nbsp; (0.70)<br>| &nbsp;&nbsp; (0.84)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.32)<br>| &nbsp;&nbsp; (0.40)<br>| &nbsp;&nbsp; (0.38)<br>| &nbsp;&nbsp; (0.70)<br>| &nbsp;&nbsp; (0.84)<br>|
| Class R6 net assets at the end of the year (in thousands) | $330159 | &nbsp;&nbsp; $265194 | &nbsp;&nbsp; $180058 | &nbsp;&nbsp; $112497 | &nbsp;&nbsp; $127710 |
| Portfolio turnover rate (%) | 94 | &nbsp;&nbsp; 75 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 45 | &nbsp;&nbsp; 49 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**111**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small Cap Value Fund**

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Period Ended** <br>**December 31,**<br>| **Period Ended** <br>**October 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022** | **2021**<sup>(a)</sup> <br>| **2021**<sup>(b)</sup> <br>|
| Net Asset Value, beginning of year | $29.67 | &nbsp;&nbsp; $29.78 | &nbsp;&nbsp; $27.76 | &nbsp;&nbsp; $33.63 | &nbsp;&nbsp; $33.49 | &nbsp;&nbsp; $32.15 |
| Income (loss) from investment operations: |  |  |  |  |  |  |
| Net investment income (loss) | 0.19 | 0.22 | 0.21 | 0.15 | 0.00 <br><sup>^</sup><br>| 0.05 |
| Net realized and unrealized gain (loss) on investments | 0.59 | 0.73 | 2.72 | &nbsp;&nbsp; (3.98)<br>| 1.37 | 1.29 |
| Total from investment operations | 0.78 | 0.95 | 2.93 | &nbsp;&nbsp; (3.83)<br>| 1.37 | 1.34 |
| Less distributions from: |  |  |  |  |  |  |
| Net investment income | 0.16 | 0.18 | 0.18 | 0.12 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain | 0.44 | 0.88 | 0.73 | 1.92 | 1.23 | &nbsp;&nbsp; — |
| Total distributions | 0.60 | 1.06 | 0.91 | 2.04 | 1.23 | &nbsp;&nbsp; — |
| Net asset value, end of period | $29.85 | &nbsp;&nbsp; $29.67 | &nbsp;&nbsp; $29.78 | &nbsp;&nbsp; $27.76 | &nbsp;&nbsp; $33.63 | &nbsp;&nbsp; $33.49 |
| Total return (%)\* | 2.61 | 3.21 | 10.59 | &nbsp;&nbsp; (11.36)<br>| 4.24 | 4.17 |
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.16 | 1.15 | 1.11 | 1.15 | 1.26 | 1.17 |
| Expenses, net of waivers and reimbursements | 1.15 | 1.15 | 1.11 | 1.15 | 1.15 | 1.15 |
| Net investment income (loss), before waivers and <br> reimbursements<br>| 0.67 | 0.74 | 0.76 | 0.48 | &nbsp;&nbsp; (0.05)<br>| 0.51 |
| Net investment income (loss), net of waivers and <br> reimbursements<br>| 0.68 | 0.74 | 0.76 | 0.48 | 0.06 | 0.53 |
| Class N net assets at the end of the year (in thousands) | $1978 | &nbsp;&nbsp; $2258 | &nbsp;&nbsp; $2591 | &nbsp;&nbsp; $2648 | &nbsp;&nbsp; $3313 | &nbsp;&nbsp; $9805 |
| Portfolio turnover rate (%)\* | 37 | &nbsp;&nbsp; 35 | &nbsp;&nbsp; 27 | &nbsp;&nbsp; 25 | &nbsp;&nbsp; 7 | &nbsp;&nbsp; 35 |

---

------

---

| | |
|:---|:---|
| (a) | For the period from November 1, 2021 to December 31, 2021. |
| (b) | For the period from July 17, 2021 (Commencement of Operations) to October 31, 2021. |
| ^ | Amount is less than $0.005 per share. |
| \* | Rates are not annualized for periods less than a year. |
| \*\* | Rates are annualized for periods less than a year. |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**112**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small Cap Value Fund (continued)**

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Period Ended** <br>**December 31,**<br>| **Years Ended** <br>**October 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022** | **2021**<sup>(a)</sup> <br>| **2021** |
| Net Asset Value, beginning of year | $29.61 | &nbsp;&nbsp; $29.74 | &nbsp;&nbsp; $27.72 | &nbsp;&nbsp; $33.58 | &nbsp;&nbsp; $33.52 | &nbsp;&nbsp; $23.79 |
| Income (loss) from investment operations: |  |  |  |  |  |  |
| Net investment income (loss) | 0.27 | 0.30 | 0.28 | 0.22 | 0.03 | 0.18 |
| Net realized and unrealized gain (loss) on <br> investments<br>| 0.60 | 0.72 | 2.72 | &nbsp;&nbsp; (3.96)<br>| 1.35 | 12.91 |
| Total from investment operations | 0.87 | 1.02 | 3.00 | &nbsp;&nbsp; (3.74)<br>| 1.38 | 13.09 |
| Less distributions from: |  |  |  |  |  |  |
| Net investment income | 0.24 | 0.27 | 0.25 | 0.20 | 0.09 | 0.11 |
| Net realized gain | 0.44 | 0.88 | 0.73 | 1.92 | 1.23 | 3.25 |
| Total distributions | 0.68 | 1.15 | 0.98 | 2.12 | 1.32 | 3.36 |
| Net asset value, end of period | $29.80 | &nbsp;&nbsp; $29.61 | &nbsp;&nbsp; $29.74 | &nbsp;&nbsp; $27.72 | &nbsp;&nbsp; $33.58 | &nbsp;&nbsp; $33.52 |
| Total return (%)\* | 2.91 | 3.44 | 10.86 | &nbsp;&nbsp; (11.12)<br>| 4.31 | 55.32 |
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 0.93 | 0.92 | 0.92 | 0.94 | 0.82 | 0.86 |
| Expenses, net of waivers and reimbursements | 0.89 | 0.89 | 0.89 | 0.89 | 0.82 | 0.86 |
| Net investment income (loss), before waivers and <br> reimbursements<br>| 0.89 | 0.97 | 0.95 | 0.67 | 0.55 | 0.52 |
| Net investment income (loss), net of waivers and <br> reimbursements<br>| 0.93 | 1.00 | 0.98 | 0.72 | 0.55 | 0.52 |
| Class I net assets at the end of the year (in thousands) | $547178 | &nbsp;&nbsp; $742417 | &nbsp;&nbsp; $813809 | &nbsp;&nbsp; $758104 | &nbsp;&nbsp; $1059157 | &nbsp;&nbsp; $1143150 |
| Portfolio turnover rate (%)\* | 37 | &nbsp;&nbsp; 35 | &nbsp;&nbsp; 27 | &nbsp;&nbsp; 25 | &nbsp;&nbsp; 7 | &nbsp;&nbsp; 35 |

---

------

(a) For the period from November 1, 2021 to December 31, 2021. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Years Ended** <br>**December 31,** | **Period Ended** <br>**December 31,**<br>| **Period Ended** <br>**October 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022** | **2021**<sup>(a)</sup> <br>| **2021**<sup>(b)</sup> <br>|
| Net Asset Value, beginning of year | $29.60 | &nbsp;&nbsp; $29.73 | &nbsp;&nbsp; $27.71 | &nbsp;&nbsp; $33.58 | &nbsp;&nbsp; $33.53 | &nbsp;&nbsp; $32.15 |
| Income (loss) from investment operations: |  |  |  |  |  |  |
| Net investment income (loss) | 0.29 | 0.34 | 0.30 | 0.26 | 0.03 | 0.06 |
| Net realized and unrealized gain (loss) on <br> investments<br>| 0.61 | 0.71 | 2.73 | &nbsp;&nbsp; (3.98)<br>| 1.35 | 1.32 |
| Total from investment operations | 0.90 | 1.05 | 3.03 | &nbsp;&nbsp; (3.72)<br>| 1.38 | 1.38 |
| Less distributions from: |  |  |  |  |  |  |
| Net investment income | 0.27 | 0.30 | 0.28 | 0.23 | 0.10 | &nbsp;&nbsp; — |
| Net realized gain | 0.44 | 0.88 | 0.73 | 1.92 | 1.23 | &nbsp;&nbsp; — |
| Total distributions | 0.71 | 1.18 | 1.01 | 2.15 | 1.33 | &nbsp;&nbsp; — |
| Net asset value, end of period | $29.79 | &nbsp;&nbsp; $29.60 | &nbsp;&nbsp; $29.73 | &nbsp;&nbsp; $27.71 | &nbsp;&nbsp; $33.58 | &nbsp;&nbsp; $33.53 |
| Total return (%)\* | 3.01 | 3.56 | 10.96 | &nbsp;&nbsp; (11.06)<br>| 4.33 | 4.26 |
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |  |  |
| Expenses | 0.80 | 0.79 | 0.79 | 0.81 | 0.78 | 0.78 |
| Net investment income (loss) | 1.02 | 1.12 | 1.08 | 0.85 | 0.59 | 0.64 |
| Class R6 net assets at the end of the year (in <br> thousands)<br>| $370300 | &nbsp;&nbsp; $607061 | &nbsp;&nbsp; $491646 | &nbsp;&nbsp; $453456 | &nbsp;&nbsp; $1006928 | &nbsp;&nbsp; $867272 |
| Portfolio turnover rate (%)\* | 37 | &nbsp;&nbsp; 35 | &nbsp;&nbsp; 27 | &nbsp;&nbsp; 25 | &nbsp;&nbsp; 7 | &nbsp;&nbsp; 35 |

---

------

(a) For the period from November 1, 2021 to December 31, 2021.

(b) For the period from July 17, 2021 (Commencement of Operations) to October 31, 2021.

\* Rates are not annualized for periods less than a year.

\*\* Rates are annualized for periods less than a year.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**113**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Small Cap Value Fund (continued)**

On July 16, 2021, Small Cap Value Fund (the "Fund") acquired the assets and assumed the liabilities of the ICM Small Company Portfolio (the "Predecessor Fund"), a series of The Advisors' Inner Circle Fund, in a reorganization (the "Reorganization"). In the Reorganization, former shareholders of the Predecessor Fund received Class I shares of the Fund. The Predecessor Fund was advised by Investment Counselors of Maryland, LLC, which was acquired by the Adviser. The Predecessor Fund's (Institutional Class shares) performance and financial history have been adopted by Class I shares of the Fund following the Reorganization and are being used going forward from the date of the Reorganization. The performance of Class I shares of the Fund therefore reflects the performance of the Predecessor Fund prior to the Reorganization. The performance of the Predecessor Fund has not been restated to reflect the annual operating expenses of Class I shares of the Fund, which were different than those of the Predecessor Fund. Because the Fund had different fees and expenses than the Predecessor Fund, the Predecessor Fund would therefore have had different performance results if it was subject to the Fund's fees and expenses.

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**114**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Global Leaders Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $10.58 | &nbsp;&nbsp; $15.21 | &nbsp;&nbsp; $13.24 | &nbsp;&nbsp; $19.17 | &nbsp;&nbsp; $17.41 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | (0.01)<br>| &nbsp;&nbsp; (0.02)<br>| &nbsp;&nbsp; (0.02)<br>| &nbsp;&nbsp; (0.04)<br>| &nbsp;&nbsp; (0.11)<br>|
| Net realized and unrealized gain (loss) on investments | 1.47 | 1.19 | 3.01 | &nbsp;&nbsp; (5.61)<br>| 2.96 |
| Total from investment operations | 1.46 | 1.17 | 2.99 | &nbsp;&nbsp; (5.65)<br>| 2.85 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.11 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain | 5.53 | 5.80 | 1.02 | 0.28 | 1.09 |
| Total distributions | 5.64 | 5.80 | 1.02 | 0.28 | 1.09 |
| Net asset value, end of period | $6.40 | &nbsp;&nbsp; $10.58 | &nbsp;&nbsp; $15.21 | &nbsp;&nbsp; $13.24 | &nbsp;&nbsp; $19.17 |
| Total return (%) | 14.82 | 7.47 | 22.67 | &nbsp;&nbsp; (29.49)<br>| 16.55 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.98 | 1.53 | 1.42 | 1.45 | 1.38 |
| Expenses, net of waivers and reimbursements | 1.15 | 1.15 | 1.15 | 1.15 | 1.15 |
| Net investment income (loss), before waivers and reimbursements | (0.91)<br>| &nbsp;&nbsp; (0.51)<br>| &nbsp;&nbsp; (0.43)<br>| &nbsp;&nbsp; (0.60)<br>| &nbsp;&nbsp; (0.79)<br>|
| Net investment income (loss), net of waivers and reimbursements | (0.08)<br>| &nbsp;&nbsp; (0.13)<br>| &nbsp;&nbsp; (0.16)<br>| &nbsp;&nbsp; (0.30)<br>| &nbsp;&nbsp; (0.56)<br>|
| Class N net assets at the end of the year (in thousands) | $1892 | &nbsp;&nbsp; $3527 | &nbsp;&nbsp; $8253 | &nbsp;&nbsp; $8317 | &nbsp;&nbsp; $13709 |
| Portfolio turnover rate (%) | 81 | &nbsp;&nbsp; 57 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; 15 | &nbsp;&nbsp; 18 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $10.77 | &nbsp;&nbsp; $15.38 | &nbsp;&nbsp; $13.35 | &nbsp;&nbsp; $19.28 | &nbsp;&nbsp; $17.47 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.02 | 0.02 | 0.01 | &nbsp;&nbsp; (0.01)<br>| &nbsp;&nbsp; (0.06)<br>|
| Net realized and unrealized gain (loss) on investments | 1.50 | 1.21 | 3.05 | &nbsp;&nbsp; (5.63)<br>| 2.96 |
| Total from investment operations | 1.52 | 1.23 | 3.06 | &nbsp;&nbsp; (5.64)<br>| 2.90 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.14 | 0.04 | 0.01 | 0.01 | &nbsp;&nbsp; — |
| Net realized gain | 5.53 | 5.80 | 1.02 | 0.28 | 1.09 |
| Total distributions | 5.67 | 5.84 | 1.03 | 0.29 | 1.09 |
| Net asset value, end of period | $6.62 | &nbsp;&nbsp; $10.77 | &nbsp;&nbsp; $15.38 | &nbsp;&nbsp; $13.35 | &nbsp;&nbsp; $19.28 |
| Total return (%) | 15.20 | 7.71 | 22.99 | &nbsp;&nbsp; (29.28)<br>| 16.78 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.72 | 1.22 | 1.14 | 1.12 | 1.07 |
| Expenses, net of waivers and reimbursements | 0.90 | 0.90 | 0.90 | 0.90 | 0.90 |
| Net investment income (loss), before waivers and reimbursements | (0.65)<br>| &nbsp;&nbsp; (0.19)<br>| &nbsp;&nbsp; (0.17)<br>| &nbsp;&nbsp; (0.27)<br>| &nbsp;&nbsp; (0.49)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.17 | 0.13 | 0.07 | &nbsp;&nbsp; (0.05)<br>| &nbsp;&nbsp; (0.32)<br>|
| Class I net assets at the end of the year (in thousands) | $13894 | &nbsp;&nbsp; $44889 | &nbsp;&nbsp; $76915 | &nbsp;&nbsp; $69987 | &nbsp;&nbsp; $124488 |
| Portfolio turnover rate (%) | 81 | &nbsp;&nbsp; 57 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; 15 | &nbsp;&nbsp; 18 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**115**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Global Leaders Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $10.77 | &nbsp;&nbsp; $15.39 | &nbsp;&nbsp; $13.35 | &nbsp;&nbsp; $19.30 | &nbsp;&nbsp; $17.47 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.03 | 0.03 | 0.02 | &nbsp;&nbsp; (0.01)<br>| &nbsp;&nbsp; (0.05)<br>|
| Net realized and unrealized gain (loss) on investments | 1.50 | 1.20 | 3.05 | &nbsp;&nbsp; (5.64)<br>| 2.97 |
| Total from investment operations | 1.53 | 1.23 | 3.07 | &nbsp;&nbsp; (5.65)<br>| 2.92 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.15 | 0.05 | 0.01 | 0.02 | &nbsp;&nbsp; — |
| Net realized gain | 5.53 | 5.80 | 1.02 | 0.28 | 1.09 |
| Total distributions | 5.68 | 5.85 | 1.03 | 0.30 | 1.09 |
| Net asset value, end of period | $6.62 | &nbsp;&nbsp; $10.77 | &nbsp;&nbsp; $15.39 | &nbsp;&nbsp; $13.35 | &nbsp;&nbsp; $19.30 |
| Total return (%) | 15.23 | 7.78 | 23.13 | &nbsp;&nbsp; (29.30)<br>| 16.90 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.63 | 1.13 | 1.05 | 1.05 | 0.99 |
| Expenses, net of waivers and reimbursements | 0.85 | 0.85 | 0.85 | 0.85 | 0.85 |
| Net investment income (loss), before waivers and reimbursements | (0.54)<br>| &nbsp;&nbsp; (0.12)<br>| &nbsp;&nbsp; (0.08)<br>| &nbsp;&nbsp; (0.30)<br>| &nbsp;&nbsp; (0.40)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.24 | 0.16 | 0.12 | &nbsp;&nbsp; (0.10)<br>| &nbsp;&nbsp; (0.26)<br>|
| Class R6 net assets at the end of the year (in thousands) | $2275 | &nbsp;&nbsp; $5761 | &nbsp;&nbsp; $15287 | &nbsp;&nbsp; $13255 | &nbsp;&nbsp; $5585 |
| Portfolio turnover rate (%) | 81 | &nbsp;&nbsp; 57 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; 15 | &nbsp;&nbsp; 18 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**116**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**International Leaders Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $19.25 | &nbsp;&nbsp; $19.45 | &nbsp;&nbsp; $17.28 | &nbsp;&nbsp; $24.28 | &nbsp;&nbsp; $22.69 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.10 | 0.06 | 0.05 | 0.04 | &nbsp;&nbsp; (0.12)<br>|
| Net realized and unrealized gain (loss) on investments | 4.26 | &nbsp;&nbsp; (0.21)<br>| 2.16 | &nbsp;&nbsp; (7.01)<br>| 2.35 |
| Total from investment operations | 4.36 | &nbsp;&nbsp; (0.15)<br>| 2.21 | &nbsp;&nbsp; (6.97)<br>| 2.23 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.23 | 0.05 | 0.04 | &nbsp;&nbsp; — | 0.00 <br><sup>^</sup><br>|
| Net realized gain | 1.47 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.03 | 0.64 |
| Total distributions | 1.70 | 0.05 | 0.04 | 0.03 | 0.64 |
| Net asset value, end of period | $21.91 | &nbsp;&nbsp; $19.25 | &nbsp;&nbsp; $19.45 | &nbsp;&nbsp; $17.28 | &nbsp;&nbsp; $24.28 |
| Total return (%) | 22.88 | &nbsp;&nbsp; (0.76)<br>| 12.77 | &nbsp;&nbsp; (28.70)<br>| 9.93 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.27 | 1.26 | 1.26 | 1.26 | 1.30 |
| Expenses, net of waivers and reimbursements | 1.15 | 1.15 | 1.15 | 1.15 | 1.15 |
| Net investment income (loss), before waivers and reimbursements | 0.34 | 0.19 | 0.17 | 0.09 | &nbsp;&nbsp; (0.65)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.46 | 0.30 | 0.28 | 0.20 | &nbsp;&nbsp; (0.50)<br>|
| Class N net assets at the end of the year (in thousands) | $24666 | &nbsp;&nbsp; $26853 | &nbsp;&nbsp; $34162 | &nbsp;&nbsp; $35966 | &nbsp;&nbsp; $47234 |
| Portfolio turnover rate (%) | 91 | &nbsp;&nbsp; 66 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 18 |

---

------

---

| | |
|:---|:---|
| ^ | Amount is less than $0.005 per share. |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $19.39 | &nbsp;&nbsp; $19.60 | &nbsp;&nbsp; $17.41 | &nbsp;&nbsp; $24.41 | &nbsp;&nbsp; $22.80 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.14 | 0.10 | 0.10 | 0.08 | &nbsp;&nbsp; (0.06)<br>|
| Net realized and unrealized gain (loss) on investments | 4.31 | &nbsp;&nbsp; (0.20)<br>| 2.18 | &nbsp;&nbsp; (7.05)<br>| 2.36 |
| Total from investment operations | 4.45 | &nbsp;&nbsp; (0.10)<br>| 2.28 | &nbsp;&nbsp; (6.97)<br>| 2.30 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.30 | 0.11 | 0.09 | &nbsp;&nbsp; — | 0.05 |
| Net realized gain | 1.47 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.03 | 0.64 |
| Total distributions | 1.77 | 0.11 | 0.09 | 0.03 | 0.69 |
| Net asset value, end of period | $22.07 | &nbsp;&nbsp; $19.39 | &nbsp;&nbsp; $19.60 | &nbsp;&nbsp; $17.41 | &nbsp;&nbsp; $24.41 |
| Total return (%) | 23.17 | &nbsp;&nbsp; (0.50)<br>| 13.09 | &nbsp;&nbsp; (28.55)<br>| 10.17 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.03 | 1.03 | 1.04 | 1.04 | 0.99 |
| Expenses, net of waivers and reimbursements | 0.90 | 0.90 | 0.90 | 0.90 | 0.90 |
| Net investment income (loss), before waivers and reimbursements | 0.52 | 0.38 | 0.39 | 0.28 | &nbsp;&nbsp; (0.33)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.65 | 0.51 | 0.53 | 0.42 | &nbsp;&nbsp; (0.24)<br>|
| Class I net assets at the end of the year (in thousands) | $645147 | &nbsp;&nbsp; $553671 | &nbsp;&nbsp; $413373 | &nbsp;&nbsp; $369171 | &nbsp;&nbsp; $591500 |
| Portfolio turnover rate (%) | 91 | &nbsp;&nbsp; 66 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 18 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**117**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**International Leaders Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $19.40 | &nbsp;&nbsp; $19.62 | &nbsp;&nbsp; $17.42 | &nbsp;&nbsp; $24.41 | &nbsp;&nbsp; $22.80 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.17 | 0.12 | 0.11 | 0.09 | &nbsp;&nbsp; (0.04)<br>|
| Net realized and unrealized gain (loss) on investments | 4.30 | &nbsp;&nbsp; (0.22)<br>| 2.19 | &nbsp;&nbsp; (7.05)<br>| 2.35 |
| Total from investment operations | 4.47 | &nbsp;&nbsp; (0.10)<br>| 2.30 | &nbsp;&nbsp; (6.96)<br>| 2.31 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.31 | 0.12 | 0.10 | &nbsp;&nbsp; — | 0.06 |
| Net realized gain | 1.47 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.03 | 0.64 |
| Total distributions | 1.78 | 0.12 | 0.10 | 0.03 | 0.70 |
| Net asset value, end of period | $22.09 | &nbsp;&nbsp; $19.40 | &nbsp;&nbsp; $19.62 | &nbsp;&nbsp; $17.42 | &nbsp;&nbsp; $24.41 |
| Total return (%) | 23.27 | &nbsp;&nbsp; (0.51)<br>| 13.20 | &nbsp;&nbsp; (28.51)<br>| 10.22 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 0.91 | 0.91 | 0.91 | 0.92 | 0.91 |
| Expenses, net of waivers and reimbursements | 0.85 | 0.85 | 0.85 | 0.85 | 0.85 |
| Net investment income (loss), before waivers and reimbursements | 0.73 | 0.52 | 0.52 | 0.44 | &nbsp;&nbsp; (0.24)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.79 | 0.58 | 0.58 | 0.51 | &nbsp;&nbsp; (0.18)<br>|
| Class R6 net assets at the end of the year (in thousands) | $425508 | &nbsp;&nbsp; $580142 | &nbsp;&nbsp; $636401 | &nbsp;&nbsp; $599084 | &nbsp;&nbsp; $667996 |
| Portfolio turnover rate (%) | 91 | &nbsp;&nbsp; 66 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 18 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**118**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**International Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $26.35 | &nbsp;&nbsp; $27.73 | &nbsp;&nbsp; $24.92 | &nbsp;&nbsp; $37.57 | &nbsp;&nbsp; $38.75 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.15 | 0.09 | 0.14 | 0.11 | &nbsp;&nbsp; (0.28)<br>|
| Net realized and unrealized gain (loss) on investments | 4.42 | 0.49 | 3.61 | &nbsp;&nbsp; (10.78)<br>| 3.51 |
| Total from investment operations | 4.57 | 0.58 | 3.75 | &nbsp;&nbsp; (10.67)<br>| 3.23 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.34 | 0.36 | 0.19 | 0.02 | &nbsp;&nbsp; — |
| Net realized gain | 4.59 | 1.60 | 0.75 | 1.96 | 4.41 |
| Total distributions | 4.93 | 1.96 | 0.94 | 1.98 | 4.41 |
| Net asset value, end of period | $25.99 | &nbsp;&nbsp; $26.35 | &nbsp;&nbsp; $27.73 | &nbsp;&nbsp; $24.92 | &nbsp;&nbsp; $37.57 |
| Total return (%) | 17.74 | 2.11 | 15.12 | &nbsp;&nbsp; (28.51)<br>| 8.68 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.34 | 1.40 | 1.39 | 1.40 | 1.46 |
| Expenses, net of waivers and reimbursements | 1.18 | 1.24 | 1.24 | 1.31 | 1.45 |
| Net investment income (loss), before waivers and reimbursements | 0.35 | 0.17 | 0.36 | 0.30 | &nbsp;&nbsp; (0.68)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.51 | 0.33 | 0.51 | 0.39 | &nbsp;&nbsp; (0.67)<br>|
| Class N net assets at the end of the year (in thousands) | $229980 | &nbsp;&nbsp; $255168 | &nbsp;&nbsp; $292273 | &nbsp;&nbsp; $301485 | &nbsp;&nbsp; $293481 |
| Portfolio turnover rate (%) | 77 | &nbsp;&nbsp; 48 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 19 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $27.31 | &nbsp;&nbsp; $28.67 | &nbsp;&nbsp; $25.74 | &nbsp;&nbsp; $38.68 | &nbsp;&nbsp; $39.65 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.23 | 0.17 | 0.21 | 0.24 | &nbsp;&nbsp; (0.15)<br>|
| Net realized and unrealized gain (loss) on investments | 4.58 | 0.51 | 3.73 | &nbsp;&nbsp; (11.16)<br>| 3.59 |
| Total from investment operations | 4.81 | 0.68 | 3.94 | &nbsp;&nbsp; (10.92)<br>| 3.44 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.41 | 0.44 | 0.26 | 0.06 | &nbsp;&nbsp; — |
| Net realized gain | 4.59 | 1.60 | 0.75 | 1.96 | 4.41 |
| Total distributions | 5.00 | 2.04 | 1.01 | 2.02 | 4.41 |
| Net asset value, end of period | $27.12 | &nbsp;&nbsp; $27.31 | &nbsp;&nbsp; $28.67 | &nbsp;&nbsp; $25.74 | &nbsp;&nbsp; $38.68 |
| Total return (%) | 18.01 | 2.38 | 15.38 | &nbsp;&nbsp; (28.33)<br>| 9.01 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.06 | 1.10 | 1.10 | 1.12 | 1.14 |
| Expenses, net of waivers and reimbursements | 0.93 | 0.99 | 0.99 | 1.06 | 1.14 |
| Net investment income (loss), before waivers and reimbursements | 0.64 | 0.46 | 0.65 | 0.76 | &nbsp;&nbsp; (0.36)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.77 | 0.57 | 0.76 | 0.82 | &nbsp;&nbsp; (0.36)<br>|
| Class I net assets at the end of the year (in thousands) | $802959 | &nbsp;&nbsp; $984762 | &nbsp;&nbsp; $992759 | &nbsp;&nbsp; $981813 | &nbsp;&nbsp; $1702775 |
| Portfolio turnover rate (%) | 77 | &nbsp;&nbsp; 48 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 19 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**119**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**International Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $27.34 | &nbsp;&nbsp; $28.70 | &nbsp;&nbsp; $25.76 | &nbsp;&nbsp; $38.72 | &nbsp;&nbsp; $39.66 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.24 | 0.19 | 0.23 | 0.21 | &nbsp;&nbsp; (0.11)<br>|
| Net realized and unrealized gain (loss) on investments | 4.59 | 0.51 | 3.73 | &nbsp;&nbsp; (11.13)<br>| 3.58 |
| Total from investment operations | 4.83 | 0.70 | 3.96 | &nbsp;&nbsp; (10.92)<br>| 3.47 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.43 | 0.46 | 0.27 | 0.08 | &nbsp;&nbsp; — |
| Net realized gain | 4.59 | 1.60 | 0.75 | 1.96 | 4.41 |
| Total distributions | 5.02 | 2.06 | 1.02 | 2.04 | 4.41 |
| Net asset value, end of period | $27.15 | &nbsp;&nbsp; $27.34 | &nbsp;&nbsp; $28.70 | &nbsp;&nbsp; $25.76 | &nbsp;&nbsp; $38.72 |
| Total return (%) | 18.07 | 2.43 | 15.47 | &nbsp;&nbsp; (28.30)<br>| 9.09 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 0.95 | 1.00 | 1.00 | 1.03 | 1.06 |
| Expenses, net of waivers and reimbursements | 0.88 | 0.94 | 0.94 | 1.01 | 1.06 |
| Net investment income (loss), before waivers and reimbursements | 0.74 | 0.56 | 0.76 | 0.69 | &nbsp;&nbsp; (0.25)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.81 | 0.62 | 0.82 | 0.71 | &nbsp;&nbsp; (0.25)<br>|
| Class R6 net assets at the end of the year (in thousands) | $88286 | &nbsp;&nbsp; $123202 | &nbsp;&nbsp; $146072 | &nbsp;&nbsp; $151338 | &nbsp;&nbsp; $126641 |
| Portfolio turnover rate (%) | 77 | &nbsp;&nbsp; 48 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 19 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**120**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Institutional International Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Institutional** | **Institutional** | **Institutional** | **Institutional** | **Institutional** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $13.72 | &nbsp;&nbsp; $14.40 | &nbsp;&nbsp; $12.82 | &nbsp;&nbsp; $19.03 | &nbsp;&nbsp; $20.37 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.13 | 0.09 | 0.09 | 0.11 | &nbsp;&nbsp; (0.05)<br>|
| Net realized and unrealized gain (loss) on investments | 2.31 | 0.26 | 1.85 | &nbsp;&nbsp; (5.47)<br>| 1.86 |
| Total from investment operations | 2.44 | 0.35 | 1.94 | &nbsp;&nbsp; (5.36)<br>| 1.81 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.21 | 0.20 | 0.13 | 0.06 | &nbsp;&nbsp; — |
| Net realized gain | 1.59 | 0.83 | 0.23 | 0.79 | 3.15 |
| Total distributions | 1.80 | 1.03 | 0.36 | 0.85 | 3.15 |
| Net asset value, end of period | $14.36 | &nbsp;&nbsp; $13.72 | &nbsp;&nbsp; $14.40 | &nbsp;&nbsp; $12.82 | &nbsp;&nbsp; $19.03 |
| Total return (%) | 18.05 | 2.41 | 15.20 | &nbsp;&nbsp; (28.28)<br>| 9.39 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 0.94 | 1.00 | 1.00 | 1.01 | 1.01 |
| Expenses, net of waivers and reimbursements | 0.88 | 0.94 | 0.94 | 0.98 | 1.01 |
| Net investment income (loss), before waivers and reimbursements | 0.81 | 0.56 | 0.61 | 0.71 | &nbsp;&nbsp; (0.22)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.87 | 0.62 | 0.67 | 0.74 | &nbsp;&nbsp; (0.22)<br>|
| Net assets at the end of the year (in thousands) | $834540 | &nbsp;&nbsp; $897044 | &nbsp;&nbsp; $929474 | &nbsp;&nbsp; $908732 | &nbsp;&nbsp; $1281843 |
| Portfolio turnover rate (%) | 79 | &nbsp;&nbsp; 50 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 19 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**121**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**International Small Cap Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.09 | &nbsp;&nbsp; $12.21 | &nbsp;&nbsp; $10.74 | &nbsp;&nbsp; $16.56 | &nbsp;&nbsp; $17.45 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.04 | 0.08 | 0.04 | 0.00 <br><sup>^</sup><br>| &nbsp;&nbsp; (0.12)<br>|
| Net realized and unrealized gain (loss) on investments | 1.77 | &nbsp;&nbsp; (0.01)<br>| 1.51 | &nbsp;&nbsp; (5.82)<br>| 1.91 |
| Total from investment operations | 1.81 | 0.07 | 1.55 | &nbsp;&nbsp; (5.82)<br>| 1.79 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.05 | 0.19 | 0.08 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 2.68 |
| Total distributions | 0.05 | 0.19 | 0.08 | &nbsp;&nbsp; — | 2.68 |
| Net asset value, end of period | $13.85 | &nbsp;&nbsp; $12.09 | &nbsp;&nbsp; $12.21 | &nbsp;&nbsp; $10.74 | &nbsp;&nbsp; $16.56 |
| Total return (%) | 14.98 | 0.55 | 14.42 | &nbsp;&nbsp; (35.14)<br>| 10.87 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.61 | 1.55 | 1.53 | 1.49 | 1.46 |
| Expenses, net of waivers and reimbursements | 1.35 | 1.35 | 1.42 | 1.49 | 1.46 |
| Net investment income (loss), before waivers and reimbursements | 0.07 | 0.47 | 0.28 | 0.04 | &nbsp;&nbsp; (0.67)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.33 | 0.67 | 0.39 | 0.04 | &nbsp;&nbsp; (0.67)<br>|
| Class N net assets at the end of the year (in thousands) | $1264 | &nbsp;&nbsp; $1322 | &nbsp;&nbsp; $1547 | &nbsp;&nbsp; $1638 | &nbsp;&nbsp; $3540 |
| Portfolio turnover rate (%) | 69 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 37 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; 52 |

---

------

---

| | |
|:---|:---|
| ^ | Amount is less than $0.005 per share. |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.27 | &nbsp;&nbsp; $12.40 | &nbsp;&nbsp; $10.90 | &nbsp;&nbsp; $16.80 | &nbsp;&nbsp; $17.66 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.08 | 0.11 | 0.07 | 0.03 | &nbsp;&nbsp; (0.07)<br>|
| Net realized and unrealized gain (loss) on investments | 1.80 | &nbsp;&nbsp; (0.02)<br>| 1.54 | &nbsp;&nbsp; (5.91)<br>| 1.93 |
| Total from investment operations | 1.88 | 0.09 | 1.61 | &nbsp;&nbsp; (5.88)<br>| 1.86 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.09 | 0.22 | 0.11 | 0.02 | 0.04 |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 2.68 |
| Total distributions | 0.09 | 0.22 | 0.11 | 0.02 | 2.72 |
| Net asset value, end of period | $14.06 | &nbsp;&nbsp; $12.27 | &nbsp;&nbsp; $12.40 | &nbsp;&nbsp; $10.90 | &nbsp;&nbsp; $16.80 |
| Total return (%) | 15.30 | 0.80 | 14.70 | &nbsp;&nbsp; (34.99)<br>| 11.17 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.34 | 1.26 | 1.25 | 1.23 | 1.19 |
| Expenses, net of waivers and reimbursements | 1.10 | 1.10 | 1.17 | 1.23 | 1.19 |
| Net investment income (loss), before waivers and reimbursements | 0.34 | 0.76 | 0.54 | 0.28 | &nbsp;&nbsp; (0.40)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.58 | 0.92 | 0.62 | 0.28 | &nbsp;&nbsp; (0.40)<br>|
| Class I net assets at the end of the year (in thousands) | $73624 | &nbsp;&nbsp; $74867 | &nbsp;&nbsp; $103520 | &nbsp;&nbsp; $98330 | &nbsp;&nbsp; $136573 |
| Portfolio turnover rate (%) | 69 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 37 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; 52 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**122**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**International Small Cap Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.35 | &nbsp;&nbsp; $12.47 | &nbsp;&nbsp; $10.97 | &nbsp;&nbsp; $16.91 | &nbsp;&nbsp; $17.76 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.08 | 0.12 | 0.08 | 0.05 | &nbsp;&nbsp; (0.06)<br>|
| Net realized and unrealized gain (loss) on investments | 1.82 | &nbsp;&nbsp; (0.01)<br>| 1.54 | &nbsp;&nbsp; (5.96)<br>| 1.95 |
| Total from investment operations | 1.90 | 0.11 | 1.62 | &nbsp;&nbsp; (5.91)<br>| 1.89 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.09 | 0.23 | 0.12 | 0.03 | 0.06 |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 2.68 |
| Total distributions | 0.09 | 0.23 | 0.12 | 0.03 | 2.74 |
| Net asset value, end of period | $14.16 | &nbsp;&nbsp; $12.35 | &nbsp;&nbsp; $12.47 | &nbsp;&nbsp; $10.97 | &nbsp;&nbsp; $16.91 |
| Total return (%) | 15.42 | 0.86 | 14.76 | &nbsp;&nbsp; (34.94)<br>| 11.27 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.23 | 1.17 | 1.15 | 1.14 | 1.10 |
| Expenses, net of waivers and reimbursements | 1.05 | 1.05 | 1.12 | 1.14 | 1.10 |
| Net investment income (loss), before waivers and reimbursements | 0.44 | 0.83 | 0.64 | 0.38 | &nbsp;&nbsp; (0.31)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.62 | 0.95 | 0.67 | 0.38 | &nbsp;&nbsp; (0.31)<br>|
| Class R6 net assets at the end of the year (in thousands) | $55364 | &nbsp;&nbsp; $84511 | &nbsp;&nbsp; $135679 | &nbsp;&nbsp; $134982 | &nbsp;&nbsp; $243398 |
| Portfolio turnover rate (%) | 69 | &nbsp;&nbsp; 49 | &nbsp;&nbsp; 37 | &nbsp;&nbsp; 51 | &nbsp;&nbsp; 52 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**123**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Leaders Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $9.21 | &nbsp;&nbsp; $8.72 | &nbsp;&nbsp; $8.29 | &nbsp;&nbsp; $11.33 | &nbsp;&nbsp; $13.26 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.07 | 0.04 | 0.05 | 0.02 | &nbsp;&nbsp; (0.06)<br>|
| Net realized and unrealized gain (loss) on investments | 2.33 | 0.46 | 0.43 | &nbsp;&nbsp; (2.98)<br>| &nbsp;&nbsp; (0.98)<br>|
| Total from investment operations | 2.40 | 0.50 | 0.48 | &nbsp;&nbsp; (2.96)<br>| &nbsp;&nbsp; (1.04)<br>|
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.08 | 0.01 | 0.05 | &nbsp;&nbsp; — | 0.01 |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.08 | 0.88 |
| Total distributions | 0.08 | 0.01 | 0.05 | 0.08 | 0.89 |
| Net asset value, end of period | $11.53 | &nbsp;&nbsp; $9.21 | &nbsp;&nbsp; $8.72 | &nbsp;&nbsp; $8.29 | &nbsp;&nbsp; $11.33 |
| Total return (%) | 26.05 | 5.69 | 5.85 | &nbsp;&nbsp; (26.11)<br>| &nbsp;&nbsp; (7.69)<br>|
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.54 | 1.50 | 1.46 | 1.48 | 1.56 |
| Expenses, net of waivers and reimbursements | 1.24 | 1.24 | 1.24 | 1.29 | 1.40 |
| Net investment income (loss), before waivers and reimbursements | 0.42 | 0.14 | 0.41 | 0.05 | &nbsp;&nbsp; (0.64)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.72 | 0.40 | 0.63 | 0.24 | &nbsp;&nbsp; (0.48)<br>|
| Class N net assets at the end of the year (in thousands) | $1082 | &nbsp;&nbsp; $879 | &nbsp;&nbsp; $1007 | &nbsp;&nbsp; $1092 | &nbsp;&nbsp; $2096 |
| Portfolio turnover rate (%) | 79 | &nbsp;&nbsp; 67 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; 40 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $9.25 | &nbsp;&nbsp; $8.76 | &nbsp;&nbsp; $8.32 | &nbsp;&nbsp; $11.33 | &nbsp;&nbsp; $13.28 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.08 | 0.06 | 0.09 | 0.06 | &nbsp;&nbsp; (0.04)<br>|
| Net realized and unrealized gain (loss) on investments | 2.36 | 0.45 | 0.42 | &nbsp;&nbsp; (2.99)<br>| &nbsp;&nbsp; (0.98)<br>|
| Total from investment operations | 2.44 | 0.51 | 0.51 | &nbsp;&nbsp; (2.93)<br>| &nbsp;&nbsp; (1.02)<br>|
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.10 | 0.02 | 0.07 | &nbsp;&nbsp; — | 0.05 |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.08 | 0.88 |
| Total distributions | 0.10 | 0.02 | 0.07 | 0.08 | 0.93 |
| Net asset value, end of period | $11.59 | &nbsp;&nbsp; $9.25 | &nbsp;&nbsp; $8.76 | &nbsp;&nbsp; $8.32 | &nbsp;&nbsp; $11.33 |
| Total return (%) | 26.43 | 5.86 | 6.13 | &nbsp;&nbsp; (25.84)<br>| &nbsp;&nbsp; (7.48)<br>|
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.27 | 1.23 | 1.18 | 1.19 | 1.28 |
| Expenses, net of waivers and reimbursements | 0.99 | 0.99 | 0.99 | 1.05 | 1.15 |
| Net investment income (loss), before waivers and reimbursements | 0.55 | 0.45 | 0.82 | 0.46 | &nbsp;&nbsp; (0.40)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.83 | 0.69 | 1.01 | 0.60 | &nbsp;&nbsp; (0.27)<br>|
| Class I net assets at the end of the year (in thousands) | $9061 | &nbsp;&nbsp; $10634 | &nbsp;&nbsp; $13772 | &nbsp;&nbsp; $29682 | &nbsp;&nbsp; $42750 |
| Portfolio turnover rate (%) | 79 | &nbsp;&nbsp; 67 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; 40 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**124**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Leaders Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $9.24 | &nbsp;&nbsp; $8.75 | &nbsp;&nbsp; $8.31 | &nbsp;&nbsp; $11.32 | &nbsp;&nbsp; $13.26 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.10 | 0.07 | 0.09 | 0.06 | &nbsp;&nbsp; (0.02)<br>|
| Net realized and unrealized gain (loss) on investments | 2.34 | 0.45 | 0.42 | &nbsp;&nbsp; (2.99)<br>| &nbsp;&nbsp; (0.98)<br>|
| Total from investment operations | 2.44 | 0.52 | 0.51 | &nbsp;&nbsp; (2.93)<br>| &nbsp;&nbsp; (1.00)<br>|
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.11 | 0.03 | 0.07 | &nbsp;&nbsp; — | 0.06 |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.08 | 0.88 |
| Total distributions | 0.11 | 0.03 | 0.07 | 0.08 | 0.94 |
| Net asset value, end of period | $11.57 | &nbsp;&nbsp; $9.24 | &nbsp;&nbsp; $8.75 | &nbsp;&nbsp; $8.31 | &nbsp;&nbsp; $11.32 |
| Total return (%) | 26.42 | 5.92 | 6.22 | &nbsp;&nbsp; (25.86)<br>| &nbsp;&nbsp; (7.35)<br>|
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.18 | 1.13 | 1.08 | 1.11 | 1.20 |
| Expenses, net of waivers and reimbursements | 0.94 | 0.94 | 0.94 | 1.00 | 1.10 |
| Net investment income (loss), before waivers and reimbursements | 0.76 | 0.60 | 0.90 | 0.50 | &nbsp;&nbsp; (0.26)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.00 | 0.79 | 1.04 | 0.61 | &nbsp;&nbsp; (0.16)<br>|
| Class R6 net assets at the end of the year (in thousands) | $85620 | &nbsp;&nbsp; $153188 | &nbsp;&nbsp; $238806 | &nbsp;&nbsp; $321319 | &nbsp;&nbsp; $428839 |
| Portfolio turnover rate (%) | 79 | &nbsp;&nbsp; 67 | &nbsp;&nbsp; 44 | &nbsp;&nbsp; 42 | &nbsp;&nbsp; 40 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**125**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.53 | &nbsp;&nbsp; $11.35 | &nbsp;&nbsp; $10.35 | &nbsp;&nbsp; $15.55 | &nbsp;&nbsp; $18.42 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.05 | 0.02 | 0.06 | 0.02 | &nbsp;&nbsp; (0.13)<br>|
| Net realized and unrealized gain (loss) on investments | 3.06 | 1.16 | 0.97 | &nbsp;&nbsp; (5.20)<br>| 0.62 |
| Total from investment operations | 3.11 | 1.18 | 1.03 | &nbsp;&nbsp; (5.18)<br>| 0.49 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.02 | &nbsp;&nbsp; — | 0.03 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.02 | 3.36 |
| Total distributions | 0.02 | &nbsp;&nbsp; — | 0.03 | 0.02 | 3.36 |
| Net asset value, end of period | $15.62 | &nbsp;&nbsp; $12.53 | &nbsp;&nbsp; $11.35 | &nbsp;&nbsp; $10.35 | &nbsp;&nbsp; $15.55 |
| Total return (%) | 24.84 | 10.40 | 9.99 | &nbsp;&nbsp; (33.33)<br>| 2.97 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.43 | 1.43 | 1.46 | 1.50 | 1.55 |
| Expenses, net of waivers and reimbursements | 1.24 | 1.24 | 1.24 | 1.36 | 1.55 |
| Net investment income (loss), before waivers and reimbursements | 0.16 | &nbsp;&nbsp; (0.06)<br>| 0.38 | 0.07 | &nbsp;&nbsp; (0.65)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.35 | 0.13 | 0.60 | 0.21 | &nbsp;&nbsp; (0.65)<br>|
| Class N net assets at the end of the year (in thousands) | $14900 | &nbsp;&nbsp; $15265 | &nbsp;&nbsp; $13748 | &nbsp;&nbsp; $14664 | &nbsp;&nbsp; $28565 |
| Portfolio turnover rate (%) | 84 | &nbsp;&nbsp; 81 | &nbsp;&nbsp; 58 | &nbsp;&nbsp; 92 | &nbsp;&nbsp; 52 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.82 | &nbsp;&nbsp; $11.60 | &nbsp;&nbsp; $10.58 | &nbsp;&nbsp; $15.85 | &nbsp;&nbsp; $18.66 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.08 | 0.04 | 0.09 | 0.05 | &nbsp;&nbsp; (0.07)<br>|
| Net realized and unrealized gain (loss) on investments | 3.14 | 1.19 | 0.99 | &nbsp;&nbsp; (5.30)<br>| 0.62 |
| Total from investment operations | 3.22 | 1.23 | 1.08 | &nbsp;&nbsp; (5.25)<br>| 0.55 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.06 | 0.01 | 0.06 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.02 | 3.36 |
| Total distributions | 0.06 | 0.01 | 0.06 | 0.02 | 3.36 |
| Net asset value, end of period | $15.98 | &nbsp;&nbsp; $12.82 | &nbsp;&nbsp; $11.60 | &nbsp;&nbsp; $10.58 | &nbsp;&nbsp; $15.85 |
| Total return (%) | 25.18 | 10.62 | 10.23 | &nbsp;&nbsp; (33.14)<br>| 3.25 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.18 | 1.18 | 1.20 | 1.24 | 1.27 |
| Expenses, net of waivers and reimbursements | 0.99 | 0.99 | 0.99 | 1.11 | 1.27 |
| Net investment income (loss), before waivers and reimbursements | 0.39 | 0.16 | 0.61 | 0.32 | &nbsp;&nbsp; (0.37)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.58 | 0.35 | 0.82 | 0.45 | &nbsp;&nbsp; (0.37)<br>|
| Class I net assets at the end of the year (in thousands) | $317344 | &nbsp;&nbsp; $252524 | &nbsp;&nbsp; $173377 | &nbsp;&nbsp; $174884 | &nbsp;&nbsp; $190985 |
| Portfolio turnover rate (%) | 84 | &nbsp;&nbsp; 81 | &nbsp;&nbsp; 58 | &nbsp;&nbsp; 92 | &nbsp;&nbsp; 52 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**126**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $12.98 | &nbsp;&nbsp; $11.74 | &nbsp;&nbsp; $10.71 | &nbsp;&nbsp; $16.04 | &nbsp;&nbsp; $18.84 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.09 | 0.05 | 0.09 | 0.06 | &nbsp;&nbsp; (0.05)<br>|
| Net realized and unrealized gain (loss) on investments | 3.18 | 1.21 | 1.01 | &nbsp;&nbsp; (5.37)<br>| 0.63 |
| Total from investment operations | 3.27 | 1.26 | 1.10 | &nbsp;&nbsp; (5.31)<br>| 0.58 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.07 | 0.02 | 0.07 | &nbsp;&nbsp; — | 0.02 |
| Net realized gain |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.02 | 3.36 |
| Total distributions | 0.07 | 0.02 | 0.07 | 0.02 | 3.38 |
| Net asset value, end of period | $16.18 | &nbsp;&nbsp; $12.98 | &nbsp;&nbsp; $11.74 | &nbsp;&nbsp; $10.71 | &nbsp;&nbsp; $16.04 |
| Total return (%) | 25.23 | 10.71 | 10.26 | &nbsp;&nbsp; (33.13)<br>| 3.37 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.05 | 1.06 | 1.08 | 1.14 | 1.17 |
| Expenses, net of waivers and reimbursements | 0.94 | 0.94 | 0.94 | 1.06 | 1.17 |
| Net investment income (loss), before waivers and reimbursements | 0.51 | 0.31 | 0.68 | 0.41 | &nbsp;&nbsp; (0.27)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.62 | 0.43 | 0.82 | 0.49 | &nbsp;&nbsp; (0.27)<br>|
| Class R6 net assets at the end of the year (in thousands) | $682242 | &nbsp;&nbsp; $612245 | &nbsp;&nbsp; $635716 | &nbsp;&nbsp; $480586 | &nbsp;&nbsp; $822288 |
| Portfolio turnover rate (%) | 84 | &nbsp;&nbsp; 81 | &nbsp;&nbsp; 58 | &nbsp;&nbsp; 92 | &nbsp;&nbsp; 52 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**127**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets ex China Growth Fund**

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $13.21 | &nbsp;&nbsp; $11.64 | &nbsp;&nbsp; $9.41 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |
| Net investment income (loss) | 0.10 | 0.05 | 0.08 | 0.02 |
| Net realized and unrealized gain (loss) on investments | 3.57 | 1.52 | 2.25 | &nbsp;&nbsp; (0.61)<br>|
| Total from investment operations | 3.67 | 1.57 | 2.33 | &nbsp;&nbsp; (0.59)<br>|
| Less distributions from: |  |  |  |  |
| Net investment income | 0.08 | &nbsp;&nbsp; — | 0.10 | &nbsp;&nbsp; — |
| Net realized gain | 0.80 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total distributions | 0.88 | &nbsp;&nbsp; — | 0.10 | &nbsp;&nbsp; — |
| Net asset value, end of period | $16.00 | &nbsp;&nbsp; $13.21 | &nbsp;&nbsp; $11.64 | &nbsp;&nbsp; $9.41 |
| Total return (%)\* | 28.18 | 13.49 | 24.75 | &nbsp;&nbsp; (5.90)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |
| Expenses, before waivers and reimbursements | 1.86 | 2.11 | 2.35 | 2.77 |
| Expenses, net of waivers and reimbursements | 0.99 | 0.99 | 0.99 | 0.99 |
| Net investment income (loss), before waivers and reimbursements | (0.21)<br>| &nbsp;&nbsp; (0.75)<br>| &nbsp;&nbsp; (0.58)<br>| &nbsp;&nbsp; (1.40)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.66 | 0.37 | 0.78 | 0.38 |
| Class I net assets at the end of the year (in thousands) | $14860 | &nbsp;&nbsp; $9452 | &nbsp;&nbsp; $2841 | &nbsp;&nbsp; $9 |
| Portfolio turnover rate (%)\* | 84 | &nbsp;&nbsp; 69 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 64 |

---

------

(a) For the period from July 29, 2022 (Commencement of Operations) to December 31, 2022. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $13.23 | &nbsp;&nbsp; $11.65 | &nbsp;&nbsp; $9.42 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |
| Net investment income (loss) | 0.11 | 0.06 | 0.08 | 0.02 |
| Net realized and unrealized gain (loss) on investments | 3.58 | 1.52 | 2.25 | &nbsp;&nbsp; (0.60)<br>|
| Total from investment operations | 3.69 | 1.58 | 2.33 | &nbsp;&nbsp; (0.58)<br>|
| Less distributions from: |  |  |  |  |
| Net investment income | 0.09 | &nbsp;&nbsp; — | 0.10 | &nbsp;&nbsp; — |
| Net realized gain | 0.80 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total distributions | 0.89 | &nbsp;&nbsp; — | 0.10 | &nbsp;&nbsp; — |
| Net asset value, end of period | $16.03 | &nbsp;&nbsp; $13.23 | &nbsp;&nbsp; $11.65 | &nbsp;&nbsp; $9.42 |
| Total return (%)\* | 28.25 | 13.56 | 24.75 | &nbsp;&nbsp; (5.80)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |
| Expenses, before waivers and reimbursements | 1.76 | 2.01 | 2.26 | 2.78 |
| Expenses, net of waivers and reimbursements | 0.94 | 0.94 | 0.94 | 0.94 |
| Net investment income (loss), before waivers and reimbursements | (0.09)<br>| &nbsp;&nbsp; (0.57)<br>| &nbsp;&nbsp; (0.53)<br>| &nbsp;&nbsp; (1.42)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.73 | 0.50 | 0.79 | 0.42 |
| Class R6 net assets at the end of the year (in thousands) | $42729 | &nbsp;&nbsp; $26020 | &nbsp;&nbsp; $19169 | &nbsp;&nbsp; $13024 |
| Portfolio turnover rate (%)\* | 84 | &nbsp;&nbsp; 69 | &nbsp;&nbsp; 55 | &nbsp;&nbsp; 64 |

---

------

(a) For the period from July 29, 2022 (Commencement of Operations) to December 31, 2022. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**128**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets ex China Growth Fund (continued)**

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**129**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Small Cap Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class N** | **Class N** | **Class N** | **Class N** | **Class N** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $21.26 | &nbsp;&nbsp; $19.66 | &nbsp;&nbsp; $16.13 | &nbsp;&nbsp; $23.52 | &nbsp;&nbsp; $22.22 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.28 | 0.06 | 0.03 | &nbsp;&nbsp; (0.01)<br>| &nbsp;&nbsp; (0.20)<br>|
| Net realized and unrealized gain (loss) on investments | 2.53 | 1.54 | 3.51 | &nbsp;&nbsp; (6.59)<br>| 3.53 |
| Total from investment operations | 2.81 | 1.60 | 3.54 | &nbsp;&nbsp; (6.60)<br>| 3.33 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.19 | &nbsp;&nbsp; — | 0.01 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain | 1.89 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.79 | 2.03 |
| Total distributions | 2.08 | &nbsp;&nbsp; — | 0.01 | 0.79 | 2.03 |
| Net asset value, end of period | $21.99 | &nbsp;&nbsp; $21.26 | &nbsp;&nbsp; $19.66 | &nbsp;&nbsp; $16.13 | &nbsp;&nbsp; $23.52 |
| Total return (%) | 13.68 | 8.09 | 21.93 | &nbsp;&nbsp; (28.12)<br>| 15.23 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.70 | 1.70 | 1.70 | 1.69 | 1.60 |
| Expenses, net of waivers and reimbursements | 1.40 | 1.40 | 1.45 | 1.55 | 1.55 |
| Net investment income (loss), before waivers and reimbursements | 1.01 | &nbsp;&nbsp; (0.01)<br>| &nbsp;&nbsp; (0.07)<br>| &nbsp;&nbsp; (0.18)<br>| &nbsp;&nbsp; (0.88)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.31 | 0.29 | 0.18 | &nbsp;&nbsp; (0.04)<br>| &nbsp;&nbsp; (0.83)<br>|
| Class N net assets at the end of the year (in thousands) | $3705 | &nbsp;&nbsp; $4021 | &nbsp;&nbsp; $3857 | &nbsp;&nbsp; $3069 | &nbsp;&nbsp; $4262 |
| Portfolio turnover rate (%) | 261 | &nbsp;&nbsp; 188 | &nbsp;&nbsp; 117 | &nbsp;&nbsp; 101 | &nbsp;&nbsp; 76 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $21.63 | &nbsp;&nbsp; $19.96 | &nbsp;&nbsp; $16.37 | &nbsp;&nbsp; $23.79 | &nbsp;&nbsp; $22.40 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.34 | 0.11 | 0.07 | 0.04 | &nbsp;&nbsp; (0.14)<br>|
| Net realized and unrealized gain (loss) on investments | 2.59 | 1.56 | 3.57 | &nbsp;&nbsp; (6.67)<br>| 3.56 |
| Total from investment operations | 2.93 | 1.67 | 3.64 | &nbsp;&nbsp; (6.63)<br>| 3.42 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.25 | &nbsp;&nbsp; — | 0.05 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net realized gain | 1.89 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.79 | 2.03 |
| Total distributions | 2.14 | &nbsp;&nbsp; — | 0.05 | 0.79 | 2.03 |
| Net asset value, end of period | $22.42 | &nbsp;&nbsp; $21.63 | &nbsp;&nbsp; $19.96 | &nbsp;&nbsp; $16.37 | &nbsp;&nbsp; $23.79 |
| Total return (%) | 13.94 | 8.37 | 22.25 | &nbsp;&nbsp; (27.93)<br>| 15.51 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.43 | 1.42 | 1.43 | 1.40 | 1.31 |
| Expenses, net of waivers and reimbursements | 1.15 | 1.15 | 1.20 | 1.30 | 1.30 |
| Net investment income (loss), before waivers and reimbursements | 1.27 | 0.25 | 0.18 | 0.11 | &nbsp;&nbsp; (0.59)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.55 | 0.52 | 0.41 | 0.21 | &nbsp;&nbsp; (0.58)<br>|
| Class I net assets at the end of the year (in thousands) | $135573 | &nbsp;&nbsp; $153032 | &nbsp;&nbsp; $134297 | &nbsp;&nbsp; $108401 | &nbsp;&nbsp; $171994 |
| Portfolio turnover rate (%) | 261 | &nbsp;&nbsp; 188 | &nbsp;&nbsp; 117 | &nbsp;&nbsp; 101 | &nbsp;&nbsp; 76 |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**130**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Small Cap Growth Fund (continued)**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** |
|  | **2025** | **2024** | **2023** | **2022** | **2021** |
| Net asset value, beginning of year | $21.70 | &nbsp;&nbsp; $20.02 | &nbsp;&nbsp; $16.41 | &nbsp;&nbsp; $23.84 | &nbsp;&nbsp; $22.44 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.35 | 0.11 | 0.08 | 0.05 | &nbsp;&nbsp; (0.12)<br>|
| Net realized and unrealized gain (loss) on investments | 2.60 | 1.57 | 3.59 | &nbsp;&nbsp; (6.69)<br>| 3.56 |
| Total from investment operations | 2.95 | 1.68 | 3.67 | &nbsp;&nbsp; (6.64)<br>| 3.44 |
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.26 | &nbsp;&nbsp; — | 0.06 | &nbsp;&nbsp; — | 0.01 |
| Net realized gain | 1.89 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | 0.79 | 2.03 |
| Total distributions | 2.15 | &nbsp;&nbsp; — | 0.06 | 0.79 | 2.04 |
| Net asset value, end of period | $22.50 | &nbsp;&nbsp; $21.70 | &nbsp;&nbsp; $20.02 | &nbsp;&nbsp; $16.41 | &nbsp;&nbsp; $23.84 |
| Total return (%) | 13.99 | 8.39 | 22.37 | &nbsp;&nbsp; (27.91)<br>| 15.58 |
| Ratios to average daily net assets (%): |  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.32 | 1.31 | 1.32 | 1.31 | 1.23 |
| Expenses, net of waivers and reimbursements | 1.10 | 1.10 | 1.15 | 1.25 | 1.23 |
| Net investment income (loss), before waivers and reimbursements | 1.38 | 0.33 | 0.29 | 0.18 | &nbsp;&nbsp; (0.49)<br>|
| Net investment income (loss), net of waivers and reimbursements | 1.60 | 0.54 | 0.46 | 0.24 | &nbsp;&nbsp; (0.49)<br>|
| Class R6 net assets at the end of the year (in thousands) | $228505 | &nbsp;&nbsp; $241040 | &nbsp;&nbsp; $251558 | &nbsp;&nbsp; $211203 | &nbsp;&nbsp; $324152 |
| Portfolio turnover rate (%) | 261 | &nbsp;&nbsp; 188 | &nbsp;&nbsp; 117 | &nbsp;&nbsp; 101 | &nbsp;&nbsp; 76 |

---

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**131**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**China Growth Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022** | **2021**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $5.30 | &nbsp;&nbsp; $4.87 | &nbsp;&nbsp; $6.46 | &nbsp;&nbsp; $9.54 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.04 | 0.06 | 0.05 | 0.03 | &nbsp;&nbsp; (0.04)<br>|
| Net realized and unrealized gain (loss) on investments | 1.24 | 0.44 | &nbsp;&nbsp; (1.62)<br>| &nbsp;&nbsp; (3.11)<br>| &nbsp;&nbsp; (0.42)<br>|
| Total from investment operations | 1.28 | 0.50 | &nbsp;&nbsp; (1.57)<br>| &nbsp;&nbsp; (3.08)<br>| &nbsp;&nbsp; (0.46)<br>|
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.05 | 0.07 | 0.02 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Total distributions | 0.05 | 0.07 | 0.02 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net asset value, end of period | $6.53 | &nbsp;&nbsp; $5.30 | &nbsp;&nbsp; $4.87 | &nbsp;&nbsp; $6.46 | &nbsp;&nbsp; $9.54 |
| Total return (%)\* | 24.25 | 10.34 | &nbsp;&nbsp; (24.28)<br>| &nbsp;&nbsp; (32.43)<br>| &nbsp;&nbsp; (4.40)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |  |
| Expenses, before waivers and reimbursements | 8.54 | 9.46 | 9.78 | 5.31 | 4.74 |
| Expenses, net of waivers and reimbursements | 0.99 | 0.99 | 0.99 | 1.01 | 1.05 |
| Net investment income (loss), before waivers and reimbursements | (6.85)<br>| &nbsp;&nbsp; (7.33)<br>| &nbsp;&nbsp; (7.93)<br>| &nbsp;&nbsp; (3.90)<br>| &nbsp;&nbsp; (4.69)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.70 | 1.14 | 0.86 | 0.40 | &nbsp;&nbsp; (1.00)<br>|
| Class I net assets at the end of the year (in thousands) | $89 | &nbsp;&nbsp; $68 | &nbsp;&nbsp; $160 | &nbsp;&nbsp; $509 | &nbsp;&nbsp; $5538 |
| Portfolio turnover rate (%)\* | 73 | &nbsp;&nbsp; 81 | &nbsp;&nbsp; 97 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; 4 |

---

------

(a) For the period from August 27, 2021 (Commencement of Operations) to December 31, 2021. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022** | **2021**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $5.28 | &nbsp;&nbsp; $4.85 | &nbsp;&nbsp; $6.45 | &nbsp;&nbsp; $9.54 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.04 | 0.06 | 0.04 | 0.02 | &nbsp;&nbsp; (0.03)<br>|
| Net realized and unrealized gain (loss) on investments | 1.24 | 0.45 | &nbsp;&nbsp; (1.61)<br>| &nbsp;&nbsp; (3.11)<br>| &nbsp;&nbsp; (0.43)<br>|
| Total from investment operations | 1.28 | 0.51 | &nbsp;&nbsp; (1.57)<br>| &nbsp;&nbsp; (3.09)<br>| &nbsp;&nbsp; (0.46)<br>|
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.06 | 0.08 | 0.03 | 0.00 <br><sup>^</sup><br>| &nbsp;&nbsp; — |
| Total distributions | 0.06 | 0.08 | 0.03 | 0.00 <br><sup>^</sup><br>| &nbsp;&nbsp; — |
| Net asset value, end of period | $6.50 | &nbsp;&nbsp; $5.28 | &nbsp;&nbsp; $4.85 | &nbsp;&nbsp; $6.45 | &nbsp;&nbsp; $9.54 |
| Total return (%)\* | 24.21 | 10.46 | &nbsp;&nbsp; (24.38)<br>| &nbsp;&nbsp; (32.49)<br>| &nbsp;&nbsp; (4.40)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |  |
| Expenses, before waivers and reimbursements | 8.54 | 9.39 | 9.75 | 5.27 | 4.72 |
| Expenses, net of waivers and reimbursements | 0.94 | 0.94 | 0.94 | 0.96 | 1.00 |
| Net investment income (loss), before waivers and reimbursements | (6.85)<br>| &nbsp;&nbsp; (7.21)<br>| &nbsp;&nbsp; (8.08)<br>| &nbsp;&nbsp; (4.01)<br>| &nbsp;&nbsp; (4.61)<br>|
| Net investment income (loss), net of waivers and reimbursements | 0.75 | 1.24 | 0.73 | 0.30 | &nbsp;&nbsp; (0.89)<br>|
| Class R6 net assets at the end of the year (in thousands) | $1989 | &nbsp;&nbsp; $1660 | &nbsp;&nbsp; $1687 | &nbsp;&nbsp; $1438 | &nbsp;&nbsp; $1687 |
| Portfolio turnover rate (%)\* | 73 | &nbsp;&nbsp; 81 | &nbsp;&nbsp; 97 | &nbsp;&nbsp; 36 | &nbsp;&nbsp; 4 |

---

------

---

| | |
|:---|:---|
| (a) | For the period from August 27, 2021 (Commencement of Operations) to December 31, 2021. |
| ^ | Amount is less than $0.005 per share. |
| \* | Rates are not annualized for periods less than a year. |
| \*\* | Rates are annualized for periods less than a year. |

---

See accompanying Notes to Financial Statements.

*December 31, 2025*

**132**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**China Growth Fund (continued)**

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**133**

*William Blair Funds*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Debt Fund**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class I** | **Class I** | **Class I** | **Class I** | **Class I** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022** | **2021**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $8.06 | &nbsp;&nbsp; $7.89 | &nbsp;&nbsp; $7.44 | &nbsp;&nbsp; $9.59 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.54 | 0.59 | 0.52 | 0.48 | 0.27 |
| Net realized and unrealized gain (loss) on investments | 0.71 | 0.11 | 0.44 | &nbsp;&nbsp; (2.10)<br>| &nbsp;&nbsp; (0.40)<br>|
| Total from investment operations | 1.25 | 0.70 | 0.96 | &nbsp;&nbsp; (1.62)<br>| &nbsp;&nbsp; (0.13)<br>|
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.53 | 0.53 | 0.48 | 0.51 | 0.28 |
| Return of capital | 0.02 | &nbsp;&nbsp; — | 0.03 | 0.02 | &nbsp;&nbsp; — |
| Total distributions | 0.55 | 0.53 | 0.51 | 0.53 | 0.28 |
| Net asset value, end of period | $8.76 | &nbsp;&nbsp; $8.06 | &nbsp;&nbsp; $7.89 | &nbsp;&nbsp; $7.44 | &nbsp;&nbsp; $9.59 |
| Total return (%)\* | 16.09 | 9.06 | 13.41 | &nbsp;&nbsp; (16.93)<br>| &nbsp;&nbsp; (1.39)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.18 | 1.12 | 1.26 | 1.28 | 1.24 |
| Expenses, net of waivers and reimbursements | 0.70 | 0.70 | 0.70 | 0.70 | 0.70 |
| Net investment income (loss), before waivers and reimbursements | 5.99 | 6.92 | 6.42 | 5.39 | 4.02 |
| Net investment income (loss), net of waivers and reimbursements | 6.47 | 7.34 | 6.98 | 5.97 | 4.56 |
| Class I net assets at the end of the year (in thousands) | $40984 | &nbsp;&nbsp; $13787 | &nbsp;&nbsp; $3205 | &nbsp;&nbsp; $923 | &nbsp;&nbsp; $1484 |
| Portfolio turnover rate (%)\* | 120 | &nbsp;&nbsp; 104 | &nbsp;&nbsp; 106 | &nbsp;&nbsp; 118 | &nbsp;&nbsp; 72 |

---

------

(a) For the period from May 25, 2021 (Commencement of Operations) to December 31, 2021. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class R6** | **Class R6** | **Class R6** | **Class R6** | **Class R6** |
|  | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Years Ended December 31,** | **Period Ended** <br>**December 31,**<br>|
|  | **2025** | **2024** | **2023** | **2022** | **2021**<sup>(a)</sup> <br>|
| Net asset value, beginning of year | $8.05 | &nbsp;&nbsp; $7.88 | &nbsp;&nbsp; $7.44 | &nbsp;&nbsp; $9.59 | &nbsp;&nbsp; $10.00 |
| Income (loss) from investment operations: |  |  |  |  |  |
| Net investment income (loss) | 0.56 | 0.58 | 0.53 | 0.48 | 0.28 |
| Net realized and unrealized gain (loss) on investments | 0.70 | 0.12 | 0.42 | &nbsp;&nbsp; (2.09)<br>| &nbsp;&nbsp; (0.41)<br>|
| Total from investment operations | 1.26 | 0.70 | 0.95 | &nbsp;&nbsp; (1.61)<br>| &nbsp;&nbsp; (0.13)<br>|
| Less distributions from: |  |  |  |  |  |
| Net investment income | 0.54 | 0.53 | 0.48 | 0.52 | 0.28 |
| Return of capital | 0.02 | &nbsp;&nbsp; — | 0.03 | 0.02 | &nbsp;&nbsp; — |
| Total distributions | 0.56 | 0.53 | 0.51 | 0.54 | 0.28 |
| Net asset value, end of period | $8.75 | &nbsp;&nbsp; $8.05 | &nbsp;&nbsp; $7.88 | &nbsp;&nbsp; $7.44 | &nbsp;&nbsp; $9.59 |
| Total return (%)\* | 16.16 | 9.14 | 13.48 | &nbsp;&nbsp; (16.95)<br>| &nbsp;&nbsp; (1.32)<br>|
| Ratios to average daily net assets (%):\*\* <br>|  |  |  |  |  |
| Expenses, before waivers and reimbursements | 1.07 | 1.02 | 1.17 | 1.20 | 1.17 |
| Expenses, net of waivers and reimbursements | 0.65 | 0.65 | 0.65 | 0.65 | 0.65 |
| Net investment income (loss), before waivers and reimbursements | 6.25 | 6.83 | 6.52 | 5.50 | 4.10 |
| Net investment income (loss), net of waivers and reimbursements | 6.67 | 7.20 | 7.04 | 6.05 | 4.62 |
| Class R6 net assets at the end of the year (in thousands) | $32014 | &nbsp;&nbsp; $52304 | &nbsp;&nbsp; $50231 | &nbsp;&nbsp; $44903 | &nbsp;&nbsp; $50010 |
| Portfolio turnover rate (%)\* | 120 | &nbsp;&nbsp; 104 | &nbsp;&nbsp; 106 | &nbsp;&nbsp; 118 | &nbsp;&nbsp; 72 |

---

------

(a) For the period from May 25, 2021 (Commencement of Operations) to December 31, 2021. <br> \* Rates are not annualized for periods less than a year. <br> \*\* Rates are annualized for periods less than a year.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**134**

*Annual*

------

**Financial Highlights** — For a share outstanding throughout each period

**Emerging Markets Debt Fund (continued)**

Note: Net investment income (loss) per share is based on the average shares outstanding during the year.

**Performance cited represents past performance. Past performance does not guarantee future results and current performance may be lower or higher than the data quoted. Results shown are annual returns, which assume reinvestment of dividends and capital gains. Investment returns and principal will fluctuate and you may have a gain or loss when you sell shares. For the most current month-end performance information, please call 1-800-742-7272 or visit our website at** https://im.williamblair.com/investments/mutual-funds#performance-tab.

See accompanying Notes to Financial Statements.

*December 31, 2025*

**135**

*William Blair Funds*

------

**REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM**

To the Shareholders and the Board of Trustees of William Blair Funds

**Opinion on the Financial Statements**

We have audited the accompanying statements of assets and liabilities of William Blair Funds (the "Trust") (comprising Growth Fund, Large Cap Growth Fund, Mid Cap Value Fund, Small-Mid Cap Core Fund, Small-Mid Cap Growth Fund, Small-Mid Cap Value Fund, Small Cap Growth Fund, Small Cap Value Fund, Global Leaders Fund, International Leaders Fund, International Growth Fund, Institutional International Growth Fund, International Small Cap Growth Fund, Emerging Markets Leaders Fund, Emerging Markets Growth Fund, Emerging Markets ex China Growth Fund, Emerging Markets Small Cap Growth Fund, China Growth Fund, and Emerging Markets Debt Fund (collectively referred to as the "Funds")), including the portfolios of investments, as of December 31, 2025, and the related statements of operations and changes in net assets, and the financial highlights for each of the periods indicated in the table below and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of each of the Funds comprising William Blair Funds at December 31, 2025, the results of their operations, changes in net assets and financial highlights for each of the periods indicated in the table below, in conformity with U.S. generally accepted accounting principles.

---

| | | | |
|:---|:---|:---|:---|
| Funds comprising the William Blair Funds | Statements <br>of operations<br>| Statements <br>of changes <br>in net assets<br>| Financial <br>Highlights<br>|
| Growth Fund <br>Large Cap Growth Fund <br>Small-Mid Cap Core Fund <br>Small-Mid Cap Growth Fund <br>Small Cap Growth Fund <br>Global Leaders Fund <br>International Leaders Fund <br>International Growth Fund <br>Institutional International Growth Fund <br>International Small Cap Growth Fund <br>Emerging Markets Leaders Fund <br>Emerging Markets Growth Fund <br>Emerging Markets Small Cap Growth Fund<br>| For the year ended <br> December 31, 2025<br>| For each of the two <br> years in the period <br> ended December 31, <br> 2025<br>| For each of the five years <br> in the period ended <br> December 31, 2025<br>|
| China Growth Fund | For the year ended <br> December 31, 2025<br>| For each of the two <br> years in the period <br> ended December 31, <br> 2025<br>| For each of the four years <br> in the period ended <br> December 31, 2025 and <br> the period from <br> August 27, 2021 <br> (commencement of <br> operations) through <br> December 31, 2021<br>|
| Emerging Markets Debt Fund | For the year ended <br> December 31, 2025<br>| For each of the two <br> years in the period <br> ended December 31, <br> 2025<br>| For each of the four years <br> in the period ended <br> December 31, 2025 and <br> the period from May 25, <br> 2021 (commencement of <br> operations) through <br> December 31, 2021<br>|
| Small Cap Value Fund | For the year ended <br> December 31, 2025<br>| For each of the two <br> years in the period <br> ended December 31, <br> 2025<br>| For each of the four years <br> in the period ended <br> December 31, 2025 and <br> the period from <br> November 1, 2021 <br> through December 31, <br> 2021 and the year ended <br> October 31, 2021<br>|

---

*December 31, 2025*

**136**

*Annual*

------

**REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM**

---

| | | | |
|:---|:---|:---|:---|
| Funds comprising the William Blair Funds | Statements<br> of operations<br>| Statements<br> of changes<br> in net assets<br>| Financial<br> Highlights<br>|
| Mid Cap Value Fund | For the year ended <br> December 31, 2025<br>| For each of the two <br> years in the period <br> ended December 31, <br> 2025<br>| For each of the three <br> years ended <br> December 31, 2025 and <br> the period from <br> March 16, 2022 <br> (commencement of <br> operations) through <br> December 31, 2022<br>|
| Emerging Markets ex China Growth Fund | For the year ended <br> December 31, 2025<br>| For each of the two <br> years in the period <br> ended December 31, <br> 2025<br>| For each of the three <br> years ended <br> December 31, 2025 and <br> the period from July 29, <br> 2022 (commencement of <br> operations) through <br> December 31, 2022<br>|
| Small-Mid Cap Value Fund | For the year ended <br> December 31, 2025<br>| For each of the two <br> years in the period <br> ended December 31, <br> 2025<br>| For the each of two years <br> ended December 31, 2025 <br> and the period from <br> August 17, 2023 <br> (commencement of <br> operations) through <br> December 31, 2023<br>|

---

**Basis for Opinion**

These financial statements are the responsibility of the Trust's management. Our responsibility is to express an opinion on each of the Funds' financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) ("PCAOB") and are required to be independent with respect to the Trust in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Trust is not required to have, nor were we engaged to perform, an audit of the Trust's internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Trust's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our procedures included confirmation of securities owned as of December 31, 2025, by correspondence with the custodian and brokers, when replies were not received from brokers, we performed other auditing procedures. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

![](img6ed44d5b2.jpg)

We have served as the auditor of one or more William Blair investment companies since 1989.

Chicago, Illinois

February 25, 2026

*December 31, 2025*

**137**

*William Blair Funds*

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**(Unaudited)**

**Additional Federal Income Tax Information:**

Under Section 852(b)(3)(C) of the Code, the Funds hereby designate the following amounts as capital gain dividends for the fiscal year ended December 31, 2025 (in thousands):

---

| | |
|:---|:---|
| **Fund** | **Capital Gain Dividend** |
| Growth Fund | $58416 |
| Large Cap Growth Fund | 249129 |
| Mid Cap Value Fund | 4 |
| Small-Mid Cap Core Fund | 4279 |
| Small-Mid Cap Growth Fund | 28301 |
| Small-Mid Cap Value Fund | 21 |
| Small Cap Growth Fund | 61811 |
| Small Cap Value Fund | 11316 |
| Global Leaders Fund | 18219 |
| International Leaders Fund | 78399 |
| International Growth Fund | 208212 |
| Institutional International Growth Fund | 100507 |
| Emerging Markets Growth Fund | 381 |
| Emerging Markets ex China Growth Fund | 2840 |
| Emerging Markets Small Cap Growth Fund | 29991 |

---

*December 31, 2025*

**138**

*Annual*

------

**BOARD OF TRUSTEES**

**Vann Avedisian**

*Co-founder and Partner, Newbond Holdings*

**Kathleen Barr, Chair**

*Retired Senior Managing Director, PNC Capital Advisors, LLC*

**Michelle Borré**

*Retired Senior Portfolio Manager and Senior Vice President, OppenheimerFunds*

**Cissie Citardi**

*Partner, William Blair*

**Daniel Leib**

*Chief Executive Officer, Donnelley Financial Solutions, Inc.*

**Dorri McWhorter**

*President and Chief Executive Officer, The Executives' Club of Chicago*

**Steven Zenz**

*Retired Partner, KPMG LLP*

------

**Officers**

------

Lisa Rusch, *President*

Alaina Anderson, CFA, *Senior Vice President*

Marcelo Assalin, CFA, *Senior Vice President*

Paul Birchenough, *Senior Vice President*

Daniel Crowe, CFA, *Senior Vice President*

Robert J. Duwa, CFA, *Senior Vice President*

Simon Fennell, *Senior Vice President*

Matthew Fleming*,* CFA*, Senior Vice President*

James S. Golan, CFA, *Senior Vice President*

William V. Heaphy, CFA, *Senior Vice President*

Todd M. McClone, CFA, *Senior Vice President*

Casey K. Preyss, CFA, *Senior Vice President*

David P. Ricci, CFA, *Senior Vice President*

Marco Ruijer, CFA, *Senior Vice President*

Hugo Scott-Gall, *Senior Vice President*

Ward D. Sexton, CFA, *Senior Vice President*

Andrew Siepker, CFA, *Senior Vice President*

Ian Smith, *Senior Vice President*

Mark C. Thompson, CFA, *Senior Vice President*

Vivian Lin Thurston, CFA, *Senior Vice President*

Dan Zelazny, *Senior Vice President*

Nicholas Zimmerman, CFA, *Senior Vice President*

Mark S. Goodman, CFA, *Vice President*

Chandan Khanna, *Vice President*

Jared Lou, CFA, *Vice President*

Arun Sharma, *Vice President*

Daniel Carey, *Chief Legal Officer and Assistant Secretary*

E. Laura Simsic, *Chief Compliance Officer* 

John M. Raczek, *Treasurer*

Andrew T. Pfau, *Secretary*

David M. Cihak, *Assistant Treasurer*

**Investment Adviser**

William Blair Investment Management, LLC

**Distributor**

William Blair & Company, L.L.C.

**Independent Registered Public Accounting Firm**

Ernst & Young LLP

**Transfer Agent**

SS&C GIDS, Inc.

For customer assistance, call 1-800-635-2886

P.O. Box 219137

Kansas City, Missouri 64121-9137

*December 31, 2025*

**139**

*William Blair Funds*

------

William Blair Funds

U.S. EQUITY

------

Growth Fund

------

Large Cap Growth Fund

------

Mid Cap Value Fund

------

Small-Mid Cap Core Fund

------

Small-Mid Cap Growth Fund

------

Small-Mid Cap Value Fund

------

Small Cap Growth Fund

------

Small Cap Value Fund

------

GLOBAL EQUITY

------

Global Leaders Fund

------

INTERNATIONAL EQUITY

------

International Leaders Fund

------

International Growth Fund

------

Institutional International Growth Fund

------

International Small Cap Growth Fund

------

Emerging Markets Leaders Fund

------

Emerging Markets Growth Fund

------

Emerging Markets ex China Growth Fund

------

Emerging Markets Small Cap Growth Fund

------

China Growth Fund

------

EMERGING MARKETS DEBT

------

Emerging Markets Debt Fund

------

+1 800 742 7272

williamblairfunds.com

<sup>©</sup>William Blair & Company, L.L.C., distributor

150 North Riverside Plaza

Chicago, Illinois 60606

103188

![](img6f0d4a543.jpg)

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 9. Proxy Disclosures for Open-End Management Investment Companies.**

Not applicable.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 10. Remuneration Paid to Directors, Officers, and Others of Open-End Management Investment Companies.** 

Disclosure in response to this item is included under Item 7 of this Form N-CSR.

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 11. Statement Regarding Basis for Approval of Investment Advisory Contract.** 

Not applicable.

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 12. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.**

Not applicable to this Registrant, insofar as the Registrant is not a closed-end management investment company.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 13. Portfolio Managers of Closed-End Management Investment Companies.**

Not applicable to this Registrant, insofar as the Registrant is not a closed-end management investment company.

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 14. Purchase of Equity Securities by Closed-End Management Investment Companies and Affiliated Purchasers.**

Not applicable to this Registrant, insofar as the Registrant is not a closed-end management investment company.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 15. Submission of Matters to a Vote of Security Holders.**

There have been no material changes to the procedures by which shareholders may recommend nominees to the Registrant's Board of Trustees since the Registrant last provided disclosure in response to this item.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 16. Controls and Procedures.**

* The Registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the Registrant's Disclosure Controls and Procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c)) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of these controls and procedures required by Rule 30a-3 (b) under the 1940 Act (17 CFR 270.30a-3(b) and Rules 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934, as amended to date (17 CFR 240.13a-15(b) or 240.15d-15(b)).

* There were no changes in the Registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the Registrant's internal control over financial reporting.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 17. Disclosure of Securities Lending Activities for Closed-End Management Investment Companies.**

Not applicable to this Registrant, insofar as the Registrant is not a closed-end management investment company.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Item 18. Recovery of Erroneously Awarded Compensation.**

(a) Not applicable.

(b) Not applicable.

------

**Item 19. Exhibits.**

19. (a) (1) [The Registrant's code of ethics pursuant to Item 2 of Form N-CSR is filed as an exhibit hereto.](WBFCodeOfEthicsExecutive_202.htm)

19. (a) (2) Not applicable to this Registrant.

19. (a) (3) (1) [Certification of Principal Executive Officer Required by Rule 30a-2(a) of the Investment Company Act of 1940 is filed as an exhibit hereto.](EX-99_CERT_12312025.htm)

19. (a) (3) (2) [Certification of Principal Financial Officer Required by Rule 30a-2(a) of the Investment Company Act of 1940 is filed as an exhibit hereto.](EX-99_CERT_12312025.htm)

19. (a) (4) Not applicable.

19. (a) (5) Not applicable.

19. (b) [Certifications of the Principal Executive Officer and Principal Financial Officer of the issuer as required by Rule 30a-2(b) of the Investment Company Act of 1940 are filed as exhibits hereto.](EX-99.906_CERT_12312025.htm)

------

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

---

| | |
|:---|:---|
|  | William Blair Funds |
|  | /s/ Lisa Rusch |
| By: | Lisa Rusch<br>President<br>(Principal Executive Officer) |
| Date: | February 25, 2026 |

---

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the Registrant and in the capacities and on the dates indicated.

---

| | |
|:---|:---|
|  | /s/ Lisa Rusch |
|  | Lisa Rusch<br>President<br>(Principal Executive Officer) |
| Date: | February 25, 2026 |

---

---

| | |
|:---|:---|
|  | /s/ John Raczek |
| By: | John Raczek<br>Treasurer<br>(Principal Financial Officer) |
| Date: | February 25, 2026 |

---

------

## Ex-99.Cert

#### Exhibit 19 (a) (3) (1)

#### CERTIFICATION Pursuant to Rule 30a-2(a) under the Investment Company Act of 1940 and Section 302 of the Sarbanes-Oxley Act of 2002
I, Lisa Rusch, certify that:

1. I have reviewed this report on Form N-CSR of William Blair Funds ;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date: February 25, 2026

Lisa Rusch

Principal Executive Officer

------

#### Exhibit 19 (a) (3) (2)
CERTIFICATIONPursuant to Rule 30a-2(a) under the Investment Company Act of 1940 andSection 302 of the Sarbanes-Oxley Act of 2002

I, John Raczek, certify that:

1. I have reviewed this report on Form N-CSR of William Blair Funds ;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date: February 25, 2026

John Raczek

Principal Financial Officer

------

## Ex-99.Code

#### WILLIAM BLAIR FUNDS

#### CODE OF ETHICS FOR PRINCIPAL EXECUTIVE AND

#### SENIOR FINANCIAL OFFICERS
I. Covered Officers/Purpose of the Code

This code of ethics (the "Code") for the William Blair Funds (the "Trust") applies to the Trust's Principal Executive Officer and Principal Financial Officer (the "Covered Officers" each of whom are set forth in Exhibit A) for the purpose of promoting:

· honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships;

· full, fair, accurate, timely and understandable disclosure in reports and documents that a registrant files with, or submits to, the Securities and Exchange Commission ("SEC") and in other public communications made by the Trust;

· compliance with applicable governmental laws, rules and regulations;

· the prompt internal reporting of violations of the Code to an appropriate person or persons identified in the Code; and

· accountability for adherence to the Code.

Each Covered Officer should adhere to a high standard of business ethics and should be sensitive to situations that may give rise to actual as well as apparent conflicts of interest.

II. Conflicts of Interest

**Overview. A "conflict of interest" occurs when a Covered Officer's private interest interferes with the interests of, or his service to, the Trust. For example, a conflict of interest would arise if a Covered Officer, or a member of his family, receives improper personal benefits as a result of his position with the Trust.** 

Certain conflicts of interest arise out of the relationships between Covered Officers and the Trust and already are subject to conflict of interest provisions in the Investment Company Act of 1940 (the "1940 Act") and the Investment Advisers Act of 1940 (the "Advisers Act"). For example, Covered Officers may not individually engage in certain transactions (such as the purchase or sale of securities or other property) with the Trust because of their status as "affiliated persons" of the Trust. The Trust's and the investment adviser's compliance programs and procedures are designed to prevent, or identify and correct, violations of these provisions. This Code does not, and is not intended to, repeat or replace these programs and procedures, and such conflicts fall outside of the parameters of this Code.

Although typically not presenting an opportunity for improper personal benefit, conflicts arise from, or as a result of, the contractual relationships between the Trust and the Trust's investment adviser, William Blair Investment Management, LLC and principal underwriter, William Blair & Company, L.L.C. (collectively "William Blair"), of which the Covered Officers are also principals or employees. As a result, this Code

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recognizes that the Covered Officers will, in the normal course of their duties (whether formally for the Trust or for William Blair, or for both), be involved in establishing policies and implementing decisions that will have different effects on William Blair and the Trust. The participation of the Covered Officers in such activities is inherent in the contractual relationships between the Trust and William Blair and is consistent with the performance by the Covered Officers of their duties as officers of the Trust. Thus, if performed in conformity with the provisions of the 1940 Act and the Advisers Act, such activities will be deemed to have been handled ethically.

Other conflicts of interest are covered by the Code, even if such conflicts of interest are not subject to provisions in the 1940 Act and the Advisers Act. The following list provides examples of conflicts of interest under the Code, but Covered Officers should keep in mind that these examples are not exhaustive. The overarching principle is that the personal interest of a Covered Officer should not be placed improperly before the interest of the Trust.

Each Covered Officer must:

· not use his personal influence or personal relationships improperly to influence investment decisions or financial reporting by the Trust whereby the Covered Officer would benefit personally to the detriment of the Trust;

· not cause the Trust to take action, or fail to take action, for the individual personal benefit of the Covered Officer rather than for the benefit of the Trust; or

· not retaliate against any other Covered Officer or any employee of the Trust or its affiliated persons for reports of potential violations that are made in good faith.

There are some conflict of interest situations that should always be approved by William Blair's General Counsel if material. Examples of these include:

· any ownership interest in (other than insubstantial interests in publicly traded entities), or any consulting or employment relationship with, any of the Trust's service providers, other than William Blair or any affiliated person thereof; and

· a direct or indirect financial interest in commissions, transaction charges or spreads paid by the Trust for effecting portfolio transactions or for selling or redeeming shares other than an interest arising from the Covered Officer's employment, such as compensation or equity ownership.

III. Disclosure and Compliance

· Each Covered Officer should familiarize himself with the disclosure requirements generally applicable to the Trust;

· each Covered Officer should not knowingly misrepresent, or cause others to misrepresent, facts about the Trust to others, whether within o r outside the Trust, including to the Trust's Board of Trustees and auditors, and to governmental regulators and self-regulatory organizations;

· each Covered Officer should, to the extent appropriate within his area of responsibility, consult with other officers and employees of the Trust and William Blair with the goal of promoting full, fair, accurate, timely and understandable disclosure in the reports and documents the Trust files with, or submits to, the SEC and in other public communications made by the Trust; and

· it is the responsibility of each Covered Officer to promote compliance with the standards and restrictions imposed by applicable laws, rules and regulations.

IV. Reporting and Accountability

Each Covered Officer must:

· upon adoption of the Code (or thereafter as applicable, upon becoming a Covered Officer), affirm in writing to the Board of Trustees that he has received, read, and understands the Code;

· annually thereafter affirm to the Board of Trustees that he has complied with the requirements of the Code; and

· notify the General Counsel promptly if he knows of any violation of this Code. Failure to do so is itself a violation of this Code.

The General Counsel is responsible for applying this Code to specific situations in which questions are presented under it and has the authority to interpret this Code in any particular situation.

The Trust will follow these procedures in investigating and enforcing this Code:

· the General Counsel will take all appropriate action to investigate any potential violations reported to him;

· if, after such investigation, the General Counsel believes that no violation has occurred, the General Counsel is not required to take any further action;

· any matter that the General Counsel believes is a violation or that the General Counsel believes should be reviewed by the Trust's Board of Trustees will be reported to the Trust's Board of Trustees;

· based upon its review of any matter referred to it, the Trust's Board of Trustees shall determine whether or not a violation has occurred, whether a grant of waiver is appropriate or whether some other action should be taken. Based upon its determination, the Trust's Board of Trustees may take such action as it deems appropriate, which may include without limitation, the modifications of applicable policies and procedures, and/or the notification to appropriate personnel of William Blair; and

· any changes to or waivers of this Code will, to the extent required, be disclosed as provided by SEC rules.

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V. Other Policies and Procedures

This Code shall be the sole code of ethics adopted by the Trust for purposes of Section 406 of the Sarbanes-Oxley Act and the rules and forms applicable to registered investment companies thereunder. Insofar as other policies or procedures of the Trust, William Blair or other service providers govern or purport to govern the behavior or activities of the Covered Officers who are subject to this Code, they are superseded by this Code to the extent that they overlap or conflict with the provisions of this Code. The Trust's and William Blair's code of ethics under Rule 17j-1 under the 1940 Act and William Blair's more detailed policies and procedures set forth in The Code of Ethics for William Blair Investment Management, LLC, William Blair & Company, L.L.C. and the William Blair Funds, the Investment Management Personal Trading Policy and the William Blair Compliance Manual are separate requirements applying to the Covered Officers and others, and are not part of this Code.

VI. Amendments

Any amendments to this Code, other than amendments to Exhibit A, must be approved or ratified by a majority vote of the Board, including a majority of independent trustees.

VII. Confidentiality

All reports and records prepared or maintained pursuant to this Code will be considered confidential and shall be maintained and protected accordingly. Except as otherwise required by law or this Code, such matters shall not be disclosed to anyone other than the Board of Trustees, counsel to the Trust, the Trust and William Blair.

VIII. Internal Use

The Code is intended solely for the internal use by the Trust and does not constitute an admission, by or on behalf of the Trust, as to any fact, circumstance, or legal conclusion.

Effective: July 17, 2003

Amended: October 27, 2009, July 1, 2015, August 23, 2017, February 1, 2018, February 1, 2020, and July 30, 2025.

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#### EXHIBIT A
Persons Covered by this Code of Ethics

Lisa Rusch, Principal Executive Officer

John Raczek, Principal Financial Officer

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#### Affirmation to the Board of Trustees
I am a Covered Officer under the William Blair Funds Code of Ethics for Principal Executive and Senior Financial Officers (the "Code"). I affirm that I have received, read and understand the Code.

Date: _______________________________ ______________________________

Name: ________________________

Title: _________________________

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## Exhibit 99.906

#### Exhibit 19 (b)

#### CERTIFICATIONS Pursuant to Rule 30a-2(b) under the Investment Company Act of 1940 and Section 906 of the Sarbanes-Oxley Act of 2002
Name of Issuer: William Blair Funds

Each of the undersigned, the principal executive officer and principal financial officer of the above named issuer, hereby certify to the best of their knowledge and belief that:

1. The Registrant's annual report on Form N-CSR fully complies with the requirements of Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the issuer.

By: Lisa Rusch

Principal Executive Officer

Date: February 25, 2026

By: John Raczek

Principal Financial Officer

Date: February 25, 2026

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