# EDGAR Filing Document

**Accession Number:** 0000002110
**File Stem:** 0000002110-25-000019
**Filing Date:** 2025-9
**Character Count:** 441484
**Document Hash:** ded4b3be5fb392ae43ad4f7a371f410c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000002110-25-000019.hdr.sgml**: 20250904

**ACCESSION NUMBER**: 0000002110-25-000019

**CONFORMED SUBMISSION TYPE**: N-CSRS

**PUBLIC DOCUMENT COUNT**: 60

**CONFORMED PERIOD OF REPORT**: 20250630

**FILED AS OF DATE**: 20250904

**DATE AS OF CHANGE**: 20250904

**EFFECTIVENESS DATE**: 20250904

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** COLUMBIA ACORN TRUST
- **CENTRAL INDEX KEY:** 0000002110

**ORGANIZATION NAME:**
- **EIN:** 362692100
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** N-CSRS
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-01829
- **FILM NUMBER:** 251293228

**BUSINESS ADDRESS:**
- **STREET 1:** 71 S. WACKER DRIVE, SUITE 2500
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606
- **BUSINESS PHONE:** 3126349200

**MAIL ADDRESS:**
- **STREET 1:** 71 S. WACKER DRIVE, SUITE 2500
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** LIBERTY ACORN TRUST
- **DATE OF NAME CHANGE:** 20010424

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ACORN INVESTMENT TRUST
- **DATE OF NAME CHANGE:** 19940204

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ACORN FUND INC
- **DATE OF NAME CHANGE:** 19920703

## Series and Classes Contracts Data

### Columbia Acorn Fund (Series ID: S000009184)

| Class ID   | Class Name                                | Ticker Symbol   |
|:---|:---|:---|
| C000024954 | Columbia Acorn Fund Class A               | LACAX           |
| C000024956 | Columbia Acorn Fund Class C               | LIACX           |
| C000024957 | Columbia Acorn Fund Institutional Class   | ACRNX           |
| C000122736 | Columbia Acorn Fund Institutional 2 Class | CRBRX           |
| C000122737 | Columbia Acorn Fund Institutional 3 Class | CRBYX           |
| C000251059 | Columbia Acorn Fund Class S               | ACRSX           |

### Columbia Acorn International (Series ID: S000009185)

| Class ID   | Class Name                                         | Ticker Symbol   |
|:---|:---|:---|
| C000024958 | Columbia Acorn International Class A               | LAIAX           |
| C000024961 | Columbia Acorn International Institutional Class   | ACINX           |
| C000097733 | Columbia Acorn International Institutional 2 Class | CAIRX           |
| C000122739 | Columbia Acorn International Institutional 3 Class | CCYIX           |
| C000251060 | Columbia Acorn International Class S               | CCIDX           |

### Columbia Acorn International Select (Series ID: S000009188)

| Class ID   | Class Name                                                | Ticker Symbol   |
|:---|:---|:---|
| C000024970 | Columbia Acorn International Select Class A               | LAFAX           |
| C000024973 | Columbia Acorn International Select Institutional Class   | ACFFX           |
| C000122746 | Columbia Acorn International Select Institutional 2 Class | CRIRX           |
| C000122747 | Columbia Acorn International Select Institutional 3 Class | CSIRX           |
| C000251061 | Columbia Acorn International Select Class S               | ACFEX           |

### Columbia Thermostat Fund (Series ID: S000009189)

| Class ID   | Class Name                                     | Ticker Symbol   |
|:---|:---|:---|
| C000024974 | Columbia Thermostat Fund Class A               | CTFAX           |
| C000024976 | Columbia Thermostat Fund Class C               | CTFDX           |
| C000024977 | Columbia Thermostat Fund Institutional Class   | COTZX           |
| C000122750 | Columbia Thermostat Fund Institutional 2 Class | CQTRX           |
| C000122751 | Columbia Thermostat Fund Institutional 3 Class | CYYYX           |
| C000251062 | Columbia Thermostat Class S                    | COTDX           |

### Columbia Acorn European Fund (Series ID: S000033621)

| Class ID   | Class Name                                       | Ticker Symbol   |
|:---|:---|:---|
| C000103324 | Columbia Acorn European Fund Class A             | CAEAX           |
| C000103327 | Columbia Acorn European Fund Institutional Class | CAEZX           |

?xml version='1.0' encoding='ASCII'? 8dde49b45831039

#### 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

#### 811-01829

#### Columbia Acorn Trust
(Exact name of registrant as specified in charter)

------

290 Congress Street

Boston, MA 02210

(Address of principal executive offices) (Zip code)

Daniel J. Beckman

c/o Columbia Management Investment Advisers, LLC

290 Congress Street

Boston, MA 02210

Ryan C. Larrenaga, Esq.

c/o Columbia Management Investment Advisers, LLC

290 Congress Street

Boston, MA 02210

(Name and address of agent for service)

#### Registrant's telephone number, including area code:
&nbsp;&nbsp;&nbsp;&nbsp;(800) 345-6611

#### Date of fiscal year end:

#### Last Day of December

#### Date of reporting period:

#### June 30, 2025
Form N-CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may use the information provided on Form N-CSR in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-CSR unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 100 F Street, NE, Washington, DC 20549. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Reports to Stockholders

Columbia Acorn<sup>®</sup> Fund

Class A / LACAX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn<sup>®</sup> Fund (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class A | $51 1.05%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$2461733489 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;100 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;43% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;SPX Technologies, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Churchill Downs, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;GCM Grosvenor, Inc., Class A | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Parsons Corp. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Curtiss-Wright Corp. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Wingstop, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Five Below, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. (The) | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;HealthEquity, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Colliers International Group, Inc. | 2.1% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711022.jpg)

Equity Sector Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711029.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn<sup>®</sup> Fund \| Class A \| SSR110_01_(08/25)

Columbia Acorn<sup>®</sup> Fund

Class C / LIACX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn<sup>®</sup> Fund (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class C | $87 1.80%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$2461733489 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;100 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;43% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;SPX Technologies, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Churchill Downs, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;GCM Grosvenor, Inc., Class A | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Parsons Corp. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Curtiss-Wright Corp. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Wingstop, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Five Below, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. (The) | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;HealthEquity, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Colliers International Group, Inc. | 2.1% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711001.jpg)

Equity Sector Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711008.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn<sup>®</sup> Fund \| Class C \| SSR110_04_(08/25)

Columbia Acorn<sup>®</sup> Fund

Institutional Class / ACRNX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn<sup>®</sup> Fund (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional Class | $39 0.80%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$2461733489 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;100 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;43% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;SPX Technologies, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Churchill Downs, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;GCM Grosvenor, Inc., Class A | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Parsons Corp. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Curtiss-Wright Corp. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Wingstop, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Five Below, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. (The) | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;HealthEquity, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Colliers International Group, Inc. | 2.1% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711436.jpg)

Equity Sector Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711443.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn<sup>®</sup> Fund \| Institutional Class \| SSR110_08_(08/25)

Columbia Acorn<sup>®</sup> Fund

Institutional 2 Class / CRBRX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn<sup>®</sup> Fund (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 2 Class | $37 0.77%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$2461733489 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;100 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;43% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;SPX Technologies, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Churchill Downs, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;GCM Grosvenor, Inc., Class A | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Parsons Corp. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Curtiss-Wright Corp. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Wingstop, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Five Below, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. (The) | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;HealthEquity, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Colliers International Group, Inc. | 2.1% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3710976.jpg)

Equity Sector Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3710978.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn<sup>®</sup> Fund \| Institutional 2 Class \| SSR110_15_(08/25)

Columbia Acorn<sup>®</sup> Fund

Institutional 3 Class / CRBYX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn<sup>®</sup> Fund (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 3 Class | $35 0.72%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$2461733489 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;100 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;43% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;SPX Technologies, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Churchill Downs, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;GCM Grosvenor, Inc., Class A | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Parsons Corp. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Curtiss-Wright Corp. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Wingstop, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Five Below, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. (The) | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;HealthEquity, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Colliers International Group, Inc. | 2.1% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711445.jpg)

Equity Sector Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711452.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn<sup>®</sup> Fund \| Institutional 3 Class \| SSR110_17_(08/25)

Columbia Acorn<sup>®</sup> Fund

Class S / ACRSX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn<sup>®</sup> Fund (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class S | $39 0.80%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$2461733489 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;100 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;43% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;SPX Technologies, Inc. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Churchill Downs, Inc. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;GCM Grosvenor, Inc., Class A | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Parsons Corp. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Curtiss-Wright Corp. | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Wingstop, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Five Below, Inc. | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Carlyle Group, Inc. (The) | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;HealthEquity, Inc. | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Colliers International Group, Inc. | 2.1% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711415.jpg)

Equity Sector Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711422.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn<sup>®</sup> Fund \| Class S \| SSR110_16_(08/25)

Columbia Acorn International<sup>®</sup>

Class A / LAIAX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International<sup>®</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class A | $66 1.22%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$925680060 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;67 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Halma PLC | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rightmove PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Fisher & Paykel Healthcare Corp., Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Auto Trader Group PLC | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Niterra Co., Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nemetschek SE | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Belimo Holding AG, Registered Shares | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;CAR Group Ltd. | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711346.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711353.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International<sup>®</sup> \| Class A \| SSR111_01_(08/25)

Columbia Acorn International<sup>®</sup>

Institutional Class / ACINX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International<sup>®</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional Class | $52 0.96%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$925680060 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;67 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Halma PLC | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rightmove PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Fisher & Paykel Healthcare Corp., Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Auto Trader Group PLC | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Niterra Co., Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nemetschek SE | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Belimo Holding AG, Registered Shares | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;CAR Group Ltd. | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711355.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711362.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International<sup>®</sup> \| Institutional Class \| SSR111_08_(08/25)

Columbia Acorn International<sup>®</sup>

Institutional 2 Class / CAIRX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International<sup>®</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 2 Class | $48 0.90%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$925680060 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;67 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdin gs
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Halma PLC | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rightmove PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Fisher & Paykel Healthcare Corp., Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Auto Trader Group PLC | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Niterra Co., Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nemetschek SE | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Belimo Holding AG, Registered Shares | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;CAR Group Ltd. | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711385.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711392.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International<sup>®</sup> \| Institutional 2 Class \| SSR111_15_(08/25)

Columbia Acorn International<sup>®</sup>

Institutional 3 Class / CCYIX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International<sup>®</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 3 Class | $46 0.85%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$925680060 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;67 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Halma PLC | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rightmove PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Fisher & Paykel Healthcare Corp., Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Auto Trader Group PLC | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Niterra Co., Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nemetschek SE | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Belimo Holding AG, Registered Shares | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;CAR Group Ltd. | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711376.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711383.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International<sup>®</sup> \| Institutional 3 Class \| SSR111_17_(08/25)

Columbia Acorn International<sup>®</sup>

Class S / CCIDX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International<sup>®</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class S | $52 0.97%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$925680060 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;67 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Halma PLC | 2.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Rightmove PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Fisher & Paykel Healthcare Corp., Ltd. | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Auto Trader Group PLC | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;Niterra Co., Ltd. | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nemetschek SE | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Belimo Holding AG, Registered Shares | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;CAR Group Ltd. | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711297.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711304.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International<sup>®</sup> \| Class S \| SSR111_16_(08/25)

Columbia Acorn International Select<sup>SM</sup>

Class A / LAFAX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International Select<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class A | $62 1.16%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$203521015 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Schneider Electric SE | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;3i Group PLC | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airbus Group SE | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bank of Ireland Group PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Adidas AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Publicis Groupe SA | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;BT Group PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nestlé SA, Registered Shares | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711288.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711283.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International Select<sup>SM</sup> \| Class A \| SSR112_01_(08/25)

Columbia Acorn International Select<sup>SM</sup>

Institutional Class / ACFFX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International Select<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional Class | $48 0.91%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$203521015 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Schneider Electric SE | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;3i Group PLC | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airbus Group SE | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bank of Ireland Group PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Adidas AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Publicis Groupe SA | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;BT Group PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nestlé SA, Registered Shares | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711208.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711215.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International Select<sup>SM</sup> \| Institutional Class \| SSR112_08_(08/25)

Columbia Acorn International Select<sup>SM</sup>

Institutional 2 Class / CRIRX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International Select<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 2 Class | $41 0.77%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$203521015 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Schneider Electric SE | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;3i Group PLC | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airbus Group SE | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bank of Ireland Group PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Adidas AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Publicis Groupe SA | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;BT Group PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nestlé SA, Registered Shares | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711238.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711245.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International Select<sup>SM</sup> \| Institutional 2 Class \| SSR112_15_(08/25)

Columbia Acorn International Select<sup>SM</sup>

Institutional 3 Class / CSIRX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International Select<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 3 Class | $38 0.71%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$203521015 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Schneider Electric SE | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;3i Group PLC | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airbus Group SE | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bank of Ireland Group PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Adidas AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Publicis Groupe SA | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;BT Group PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nestlé SA, Registered Shares | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711217.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711224.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International Select<sup>SM</sup> \| Institutional 3 Class \| SSR112_17_(08/25)

Columbia Acorn International Select<sup>SM</sup>

Class S / ACFEX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn International Select<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class S | $48 0.91%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$203521015 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;59 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;9% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Schneider Electric SE | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Capcom Co., Ltd. | 3.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;3i Group PLC | 3.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Airbus Group SE | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bank of Ireland Group PLC | 2.7% |
| &nbsp;&nbsp;&nbsp;&nbsp;ASML Holding NV | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Adidas AG | 2.6% |
| &nbsp;&nbsp;&nbsp;&nbsp;Publicis Groupe SA | 2.5% |
| &nbsp;&nbsp;&nbsp;&nbsp;BT Group PLC | 2.4% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nestlé SA, Registered Shares | 2.3% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711187.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711194.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn International Select<sup>SM</sup> \| Class S \| SSR112_16_(08/25)

Columbia Thermostat Fund<sup>SM</sup>

Class A / CTFAX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Thermostat Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class A | $25 0.49%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$1248605013 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;12 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;60% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Total Return Bond Fund, Institutional 3 Class | 14.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Corporate Income Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia U.S. Treasury Index Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Contrarian Core Fund, Institutional 3 Class | 10.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Enhanced Core Fund, Institutional 3 Class | 10.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Quality Income Fund, Institutional 3 Class | 9.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Research Enhanced Core ETF | 8.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Index Fund, Institutional 3 Class | 8.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia High Yield Bond Fund, Institutional 3 Class | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Diversified Fixed Income Allocation ETF | 6.0% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711942.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Thermostat Fund<sup>SM</sup> \| Class A \| SSR235_01_(08/25)

Columbia Thermostat Fund<sup>SM</sup>

Class C / CTFDX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Thermostat Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class C | $64 1.24%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$1248605013 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;12 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;60% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Total Return Bond Fund, Institutional 3 Class | 14.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Corporate Income Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia U.S. Treasury Index Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Contrarian Core Fund, Institutional 3 Class | 10.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Enhanced Core Fund, Institutional 3 Class | 10.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Quality Income Fund, Institutional 3 Class | 9.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Research Enhanced Core ETF | 8.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Index Fund, Institutional 3 Class | 8.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia High Yield Bond Fund, Institutional 3 Class | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Diversified Fixed Income Allocation ETF | 6.0% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711922.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Thermostat Fund<sup>SM</sup> \| Class C \| SSR235_04_(08/25)

Columbia Thermostat Fund<sup>SM</sup>

Institutional Class / COTZX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Thermostat Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional Class | $12 0.24%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$1248605013 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;12 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;60% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Total Return Bond Fund, Institutional 3 Class | 14.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Corporate Income Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia U.S. Treasury Index Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Contrarian Core Fund, Institutional 3 Class | 10.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Enhanced Core Fund, Institutional 3 Class | 10.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Quality Income Fund, Institutional 3 Class | 9.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Research Enhanced Core ETF | 8.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Index Fund, Institutional 3 Class | 8.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia High Yield Bond Fund, Institutional 3 Class | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Diversified Fixed Income Allocation ETF | 6.0% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711725.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Thermostat Fund<sup>SM</sup> \| Institutional Class \| SSR235_08_(08/25)

Columbia Thermostat Fund<sup>SM</sup>

Institutional 2 Class / CQTRX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Thermostat Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 2 Class | $10 0.19%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$1248605013 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;12 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;60% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Total Return Bond Fund, Institutional 3 Class | 14.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Corporate Income Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia U.S. Treasury Index Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Contrarian Core Fund, Institutional 3 Class | 10.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Enhanced Core Fund, Institutional 3 Class | 10.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Quality Income Fund, Institutional 3 Class | 9.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Research Enhanced Core ETF | 8.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Index Fund, Institutional 3 Class | 8.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia High Yield Bond Fund, Institutional 3 Class | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Diversified Fixed Income Allocation ETF | 6.0% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711894.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Thermostat Fund<sup>SM</sup> \| Institutional 2 Class \| SSR235_15_(08/25)

Columbia Thermostat Fund<sup>SM</sup>

Institutional 3 Class / CYYYX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Thermostat Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional 3 Class | $7 0.14%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$1248605013 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;12 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;60% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Total Return Bond Fund, Institutional 3 Class | 14.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Corporate Income Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia U.S. Treasury Index Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Contrarian Core Fund, Institutional 3 Class | 10.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Enhanced Core Fund, Institutional 3 Class | 10.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Quality Income Fund, Institutional 3 Class | 9.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Research Enhanced Core ETF | 8.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Index Fund, Institutional 3 Class | 8.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia High Yield Bond Fund, Institutional 3 Class | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Diversified Fixed Income Allocation ETF | 6.0% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711874.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Thermostat Fund<sup>SM</sup> \| Institutional 3 Class \| SSR235_17_(08/25)

Columbia Thermostat Fund<sup>SM</sup>

Class S / COTDX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Thermostat Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class S | $12 0.24%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$1248605013 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;12 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;60% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Total Return Bond Fund, Institutional 3 Class | 14.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Corporate Income Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia U.S. Treasury Index Fund, Institutional 3 Class | 11.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Contrarian Core Fund, Institutional 3 Class | 10.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Enhanced Core Fund, Institutional 3 Class | 10.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Quality Income Fund, Institutional 3 Class | 9.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Research Enhanced Core ETF | 8.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Index Fund, Institutional 3 Class | 8.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia High Yield Bond Fund, Institutional 3 Class | 5.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;Columbia Diversified Fixed Income Allocation ETF | 6.0% |

---

Asset Categories

![Graphical Representation - Allocation 1 Chart](chartimages_3711705.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Thermostat Fund<sup>SM</sup> \| Class S \| SSR235_16_(08/25)

Columbia Acorn European Fund<sup>SM</sup>

Class A / CAEAX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn European Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Class A | $75 1.37%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$41167250 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;91 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;53% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Elis SA | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Storebrand ASA | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nexans SA | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Safestore Holdings PLC | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Quilter PLC | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;LondonMetric Property PLC | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Buzzi SpA | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Banco Comercial Portugues SA | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Chemring Group PLC | 1.7% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711696.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711691.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn European Fund<sup>SM</sup> \| Class A \| SSR109_01_(08/25)

Columbia Acorn European Fund<sup>SM</sup>

Institutional Class / CAEZX

![FundLogo](images_1950.jpg)

Semi-Annual Shareholder Report \| June 30, 2025

This semi-annual shareholder report contains important information about Columbia Acorn European Fund<sup>SM</sup> (the Fund) for the period of January 1, 2025 to June 30, 2025. You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

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

---

| | |
|:---|:---|
| Class | Cost of a $10,000 investment |
| Institutional Class | $62 1.13%<sup>(a)</sup> |

---

(a) <sup>Annualized.</sup>

Key Fund Statistics

---

| | |
|:---|:---|
| **Fund net assets** | &nbsp;&nbsp;&nbsp;&nbsp;$41167250 |
| **Total number of portfolio holdings** | &nbsp;&nbsp;&nbsp;&nbsp;91 |
| **Portfolio turnover for the reporting period** | &nbsp;&nbsp;&nbsp;&nbsp;53% |

---

#### Graphical Representation of Fund Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Top Holdings

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Elis SA | 2.9% |
| &nbsp;&nbsp;&nbsp;&nbsp;CTS Eventim AG & Co. KGaA | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Storebrand ASA | 2.3% |
| &nbsp;&nbsp;&nbsp;&nbsp;Nexans SA | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Safestore Holdings PLC | 2.2% |
| &nbsp;&nbsp;&nbsp;&nbsp;Quilter PLC | 2.1% |
| &nbsp;&nbsp;&nbsp;&nbsp;LondonMetric Property PLC | 2.0% |
| &nbsp;&nbsp;&nbsp;&nbsp;Buzzi SpA | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Banco Comercial Portugues SA | 1.8% |
| &nbsp;&nbsp;&nbsp;&nbsp;Chemring Group PLC | 1.7% |

---

Equity Sector Allocation

![Graphical Representation - Allocation 1 Chart](chartimages_3711051.jpg)

Geographic Allocation

![Graphical Representation - Allocation 2 Chart](chartimages_3711058.jpg)

#### Availability of Additional Information
For additional information about the Fund, including its prospectus, financial information, holdings, federal tax information and proxy voting information, visit the Fund's website included at the beginning of this report or scan the QR code below.

![TSR - QR Code](images_1958.jpg)

The Fund is distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC. Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

Not FDIC or NCUA Insured • No Financial Institution Guarantee • May Lose Value

Columbia Acorn European Fund<sup>SM</sup> \| Institutional Class \| SSR109_08_(08/25)

------

Item 2. Code of Ethics.

Not applicable.

------

Item 3. Audit Committee Financial Expert.

Not applicable.

------

Item 4. Principal Accountant Fees and Services.

Not applicable.

------

Item 5. Audit Committee of Listed Registrants.

Not applicable.

------

Item 6. Investments.

(a) The registrant's "Schedule I – Investments in securities of unaffiliated issuers" (as set forth in 17 CFR 210.12-12) is included in Item 7 of this Form N-CSR.

(b) Not applicable.

------

Item 7. Financial Statements and Financial Highlights for Open-End Management Investment Companies.

------

![](imgfeb3345d1.jpg)

**Semi-Annual Financial Statements and Additional Information**

June 30, 2025 (Unaudited)

Columbia Acorn<sup>®</sup> Fund

Columbia Acorn International<sup>®</sup>

Columbia Acorn International Select<sup>SM</sup>

Columbia Thermostat Fund<sup>SM</sup>

Columbia Acorn European Fund<sup>SM</sup>

---

| | | |
|:---|:---|:---|
| **Not FDIC or NCUA Insured** | **No Financial Institution Guarantee** | **May Lose Value** |

---

------

**Table of Contents**

---

| | |
|:---|:---|
| [Portfolio of Investments](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_POI-CommonContent-Date-339_1) | 3 |
| [Statement of Assets and Liabilities](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_FS-CommonContent-Date_1) | 22 |
| [Statement of Operations](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_FS-CommonContent-Date_5) | 26 |
| [Statement of Changes in Net Assets](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_FS-CommonContent-Date_7) | 28 |
| [Financial Highlights](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_FIHI-CommonContent-Date-339_1) | 34 |
| [Notes to Financial Statements](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_NTF-CommonContent-Date_1) | 52 |
| [Results of Meeting of Shareholders](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_ROMOS-CommonContent-Date-339_1) | 67 |
| [Approval of Management Agreement](#xx_6eff82ed-7bf3-4d0d-938e-1719d41da639_BoardofApp-CommonContent-Date_1) | 68 |

---

Columbia Acorn Trust \| 2025

------

Portfolio of Investments

Columbia Acorn<sup>®</sup> Fund, June 30, 2025 (Unaudited)

(Percentages represent value of investments compared to net assets)

**Investments in securities**

---

| | | |
|:---|:---|:---|
| **Common Stocks 98.3%** | **Common Stocks 98.3%** | **Common Stocks 98.3%** |
| **Issuer** | **Shares** | **Value ($)** |
| **Consumer Discretionary 16.8%** | **Consumer Discretionary 16.8%** | **Consumer Discretionary 16.8%** |
| **Automobile Components 3.2%** | **Automobile Components 3.2%** | **Automobile Components 3.2%** |
| Dorman Products, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 261863 | &nbsp;&nbsp; 32122734 |
| Modine Manufacturing Co.<sup>(a)</sup> <br>| &nbsp;&nbsp; 489621 | &nbsp;&nbsp; 48227669 |
| Total |  | &nbsp;&nbsp; 80350403 |
| **Diversified Consumer Services 1.8%** | **Diversified Consumer Services 1.8%** | **Diversified Consumer Services 1.8%** |
| Bright Horizons Family Solutions, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 354003 | &nbsp;&nbsp; 43751231 |
| **Hotels, Restaurants & Leisure 5.9%** | **Hotels, Restaurants & Leisure 5.9%** | **Hotels, Restaurants & Leisure 5.9%** |
| Churchill Downs, Inc. | &nbsp;&nbsp; 583919 | &nbsp;&nbsp; 58975819 |
| Portillo's, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 1994406 | &nbsp;&nbsp; 23274718 |
| Wingstop, Inc. | &nbsp;&nbsp; 160207 | &nbsp;&nbsp; 53948105 |
| Xponential Fitness, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 1137279 | &nbsp;&nbsp; 8518220 |
| Total |  | &nbsp;&nbsp; 144716862 |
| **Household Durables 3.7%** | **Household Durables 3.7%** | **Household Durables 3.7%** |
| Cavco Industries, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 77013 | &nbsp;&nbsp; 33456757 |
| SharkNinja, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 104079 | &nbsp;&nbsp; 10302780 |
| TopBuild Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 146839 | &nbsp;&nbsp; 47537658 |
| Total |  | &nbsp;&nbsp; 91297195 |
| **Specialty Retail 2.2%** | **Specialty Retail 2.2%** | **Specialty Retail 2.2%** |
| Five Below, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 407802 | &nbsp;&nbsp; 53495466 |
| **Total Consumer Discretionary** | **Total Consumer Discretionary** | &nbsp;&nbsp; **413611157** |
| **Consumer Staples 4.8%** | **Consumer Staples 4.8%** | **Consumer Staples 4.8%** |
| **Consumer Staples Distribution & Retail 2.7%** | **Consumer Staples Distribution & Retail 2.7%** | **Consumer Staples Distribution & Retail 2.7%** |
| BJ's Wholesale Club Holdings, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 393552 | &nbsp;&nbsp; 42436712 |
| Sprouts Farmers Market, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 146710 | &nbsp;&nbsp; 24154335 |
| Total |  | &nbsp;&nbsp; 66591047 |
| **Household Products 1.1%** | **Household Products 1.1%** | **Household Products 1.1%** |
| WD-40 Co. | &nbsp;&nbsp; 124079 | &nbsp;&nbsp; 28301179 |
| **Personal Care Products 1.0%** | **Personal Care Products 1.0%** | **Personal Care Products 1.0%** |
| elf Beauty, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 194996 | &nbsp;&nbsp; 24265302 |
| **Total Consumer Staples** | **Total Consumer Staples** | &nbsp;&nbsp; **119157528** |
| **Energy 2.1%** | **Energy 2.1%** | **Energy 2.1%** |
| **Energy Equipment & Services 1.1%** | **Energy Equipment & Services 1.1%** | **Energy Equipment & Services 1.1%** |
| TechnipFMC PLC | &nbsp;&nbsp; 775723 | &nbsp;&nbsp; 26715900 |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Oil, Gas & Consumable Fuels 1.0%** | **Oil, Gas & Consumable Fuels 1.0%** | **Oil, Gas & Consumable Fuels 1.0%** |
| Antero Resources Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 606238 | &nbsp;&nbsp; 24419267 |
| **Total Energy** | **Total Energy** | &nbsp;&nbsp; **51135167** |
| **Financials 9.6%** | **Financials 9.6%** | **Financials 9.6%** |
| **Banks 1.5%** | **Banks 1.5%** | **Banks 1.5%** |
| Lakeland Financial Corp. | &nbsp;&nbsp; 232728 | &nbsp;&nbsp; 14301136 |
| Western Alliance Bancorp | &nbsp;&nbsp; 291874 | &nbsp;&nbsp; 22760334 |
| Total |  | &nbsp;&nbsp; 37061470 |
| **Capital Markets 5.5%** | **Capital Markets 5.5%** | **Capital Markets 5.5%** |
| Blue Owl Capital, Inc. | &nbsp;&nbsp; 1267936 | &nbsp;&nbsp; 24357051 |
| Carlyle Group, Inc. (The) | &nbsp;&nbsp; 1031465 | &nbsp;&nbsp; 53017301 |
| GCM Grosvenor, Inc., Class A<sup>(b)</sup> <br>| &nbsp;&nbsp; 5088526 | &nbsp;&nbsp; 58823360 |
| Total |  | &nbsp;&nbsp; 136197712 |
| **Insurance 2.6%** | **Insurance 2.6%** | **Insurance 2.6%** |
| Oscar Health, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 610688 | &nbsp;&nbsp; 13093151 |
| Ryan Specialty Holdings, Inc., Class A | &nbsp;&nbsp; 744905 | &nbsp;&nbsp; 50646091 |
| Total |  | &nbsp;&nbsp; 63739242 |
| **Total Financials** | **Total Financials** | &nbsp;&nbsp; **236998424** |
| **Health Care 20.0%** | **Health Care 20.0%** | **Health Care 20.0%** |
| **Biotechnology 6.0%** | **Biotechnology 6.0%** | **Biotechnology 6.0%** |
| Absci Corp.<sup>(a),(c)</sup> <br>| &nbsp;&nbsp; 2018380 | &nbsp;&nbsp; 5187237 |
| BridgeBio Pharma, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 283462 | &nbsp;&nbsp; 12239889 |
| Crinetics Pharmaceuticals, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 148722 | &nbsp;&nbsp; 4277245 |
| Exact Sciences Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 904095 | &nbsp;&nbsp; 48043608 |
| Insmed, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 344065 | &nbsp;&nbsp; 34626702 |
| Natera, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 80221 | &nbsp;&nbsp; 13552536 |
| Nuvalent, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 124391 | &nbsp;&nbsp; 9491033 |
| Revolution Medicines, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 159029 | &nbsp;&nbsp; 5850677 |
| Sarepta Therapeutics, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 292945 | &nbsp;&nbsp; 5009359 |
| Vaxcyte, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 153523 | &nbsp;&nbsp; 4991033 |
| Viking Therapeutics, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 209891 | &nbsp;&nbsp; 5562111 |
| Total |  | &nbsp;&nbsp; 148831430 |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn<sup>®</sup> Fund, June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Health Care Equipment & Supplies 5.9%** | **Health Care Equipment & Supplies 5.9%** | **Health Care Equipment & Supplies 5.9%** |
| Glaukos Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 423198 | &nbsp;&nbsp; 43712121 |
| Integer Holdings Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 248972 | &nbsp;&nbsp; 30616087 |
| iRhythm Technologies, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 65279 | &nbsp;&nbsp; 10050355 |
| Masimo Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 250998 | &nbsp;&nbsp; 42222884 |
| Penumbra, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 76995 | &nbsp;&nbsp; 19759227 |
| Total |  | &nbsp;&nbsp; 146360674 |
| **Health Care Providers & Services 4.6%** | **Health Care Providers & Services 4.6%** | **Health Care Providers & Services 4.6%** |
| Alignment Healthcare, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 894226 | &nbsp;&nbsp; 12519164 |
| Encompass Health Corp. | &nbsp;&nbsp; 315858 | &nbsp;&nbsp; 38733666 |
| HealthEquity, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 493029 | &nbsp;&nbsp; 51649718 |
| Pennant Group, Inc. (The)<sup>(a)</sup> <br>| &nbsp;&nbsp; 341322 | &nbsp;&nbsp; 10188462 |
| Total |  | &nbsp;&nbsp; 113091010 |
| **Life Sciences Tools & Services 3.0%** | **Life Sciences Tools & Services 3.0%** | **Life Sciences Tools & Services 3.0%** |
| Adaptive Biotechnologies Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 622888 | &nbsp;&nbsp; 7256645 |
| BioLife Solutions, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 838795 | &nbsp;&nbsp; 18067644 |
| Bio-Techne Corp. | &nbsp;&nbsp; 917224 | &nbsp;&nbsp; 47191175 |
| DNA Script<sup>(a),(d),(e),(f)</sup> <br>| &nbsp;&nbsp; 1139 | &nbsp;&nbsp; 102062 |
| Total |  | &nbsp;&nbsp; 72617526 |
| **Pharmaceuticals 0.5%** | **Pharmaceuticals 0.5%** | **Pharmaceuticals 0.5%** |
| Corcept Therapeutics, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 77397 | &nbsp;&nbsp; 5680940 |
| Structure Therapeutics, Inc., ADR<sup>(a)</sup> <br>| &nbsp;&nbsp; 303615 | &nbsp;&nbsp; 6296975 |
| Total |  | &nbsp;&nbsp; 11977915 |
| **Total Health Care** | **Total Health Care** | &nbsp;&nbsp; **492878555** |
| **Industrials 25.5%** | **Industrials 25.5%** | **Industrials 25.5%** |
| **Aerospace & Defense 5.8%** | **Aerospace & Defense 5.8%** | **Aerospace & Defense 5.8%** |
| Aerovironment, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 142748 | &nbsp;&nbsp; 40676042 |
| Axon Enterprise, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 14306 | &nbsp;&nbsp; 11844510 |
| Curtiss-Wright Corp. | &nbsp;&nbsp; 113763 | &nbsp;&nbsp; 55578914 |
| Kratos Defense & Security Solutions, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 297698 | &nbsp;&nbsp; 13828072 |
| Moog, Inc., Class A | &nbsp;&nbsp; 110160 | &nbsp;&nbsp; 19935655 |
| Total |  | &nbsp;&nbsp; 141863193 |
| **Building Products 1.0%** | **Building Products 1.0%** | **Building Products 1.0%** |
| Janus International Group, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 2969730 | &nbsp;&nbsp; 24173602 |
| **Commercial Services & Supplies 1.4%** | **Commercial Services & Supplies 1.4%** | **Commercial Services & Supplies 1.4%** |
| VSE Corp. | &nbsp;&nbsp; 261373 | &nbsp;&nbsp; 34234635 |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Construction & Engineering 3.0%** | **Construction & Engineering 3.0%** | **Construction & Engineering 3.0%** |
| MYR Group, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 146831 | &nbsp;&nbsp; 26642485 |
| Sterling Infrastructure, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 203718 | &nbsp;&nbsp; 47003854 |
| Total |  | &nbsp;&nbsp; 73646339 |
| **Electrical Equipment 0.8%** | **Electrical Equipment 0.8%** | **Electrical Equipment 0.8%** |
| Atkore, Inc. | &nbsp;&nbsp; 125411 | &nbsp;&nbsp; 8847746 |
| Bloom Energy Corp., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 426954 | &nbsp;&nbsp; 10212740 |
| Total |  | &nbsp;&nbsp; 19060486 |
| **Machinery 4.9%** | **Machinery 4.9%** | **Machinery 4.9%** |
| Esab Corp. | &nbsp;&nbsp; 221487 | &nbsp;&nbsp; 26700258 |
| Mueller Water Products, Inc., Class A | &nbsp;&nbsp; 1271817 | &nbsp;&nbsp; 30574481 |
| SPX Technologies, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 386249 | &nbsp;&nbsp; 64766232 |
| Total |  | &nbsp;&nbsp; 122040971 |
| **Marine Transportation 1.4%** | **Marine Transportation 1.4%** | **Marine Transportation 1.4%** |
| Matson, Inc. | &nbsp;&nbsp; 312353 | &nbsp;&nbsp; 34780506 |
| **Professional Services 4.3%** | **Professional Services 4.3%** | **Professional Services 4.3%** |
| Alight, Inc., Class A | &nbsp;&nbsp; 1769561 | &nbsp;&nbsp; 10015715 |
| Parsons Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 809779 | &nbsp;&nbsp; 58117839 |
| Paylocity Holding Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 203241 | &nbsp;&nbsp; 36825237 |
| Total |  | &nbsp;&nbsp; 104958791 |
| **Trading Companies & Distributors 2.9%** | **Trading Companies & Distributors 2.9%** | **Trading Companies & Distributors 2.9%** |
| Applied Industrial Technologies, Inc. | &nbsp;&nbsp; 140277 | &nbsp;&nbsp; 32607389 |
| FTAI Aviation Ltd. | &nbsp;&nbsp; 345298 | &nbsp;&nbsp; 39723082 |
| Total |  | &nbsp;&nbsp; 72330471 |
| **Total Industrials** | **Total Industrials** | &nbsp;&nbsp; **627088994** |
| **Information Technology 17.4%** | **Information Technology 17.4%** | **Information Technology 17.4%** |
| **Electronic Equipment, Instruments & Components 3.2%** | **Electronic Equipment, Instruments & Components 3.2%** | **Electronic Equipment, Instruments & Components 3.2%** |
| Celestica, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 250074 | &nbsp;&nbsp; 39039052 |
| Coherent Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 264426 | &nbsp;&nbsp; 23589443 |
| Ingram Micro Holding Corp.<sup>(c)</sup> <br>| &nbsp;&nbsp; 723453 | &nbsp;&nbsp; 15076761 |
| Total |  | &nbsp;&nbsp; 77705256 |
| **IT Services 1.1%** | **IT Services 1.1%** | **IT Services 1.1%** |
| Globant SA<sup>(a)</sup> <br>| &nbsp;&nbsp; 304490 | &nbsp;&nbsp; 27659872 |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn<sup>®</sup> Fund, June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Semiconductors & Semiconductor Equipment 1.8%** | **Semiconductors & Semiconductor Equipment 1.8%** | **Semiconductors & Semiconductor Equipment 1.8%** |
| Lattice Semiconductor Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 411552 | &nbsp;&nbsp; 20161932 |
| Marvell Technology, Inc. | &nbsp;&nbsp; 161778 | &nbsp;&nbsp; 12521617 |
| Rigetti Computing, Inc.<sup>(a),(c)</sup> <br>| &nbsp;&nbsp; 171075 | &nbsp;&nbsp; 2028950 |
| Semtech Corp.<sup>(a)</sup> <br>| &nbsp;&nbsp; 184070 | &nbsp;&nbsp; 8308920 |
| Total |  | &nbsp;&nbsp; 43021419 |
| **Software 11.1%** | **Software 11.1%** | **Software 11.1%** |
| Alkami Technology, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 603008 | &nbsp;&nbsp; 18174661 |
| Atlassian Corp., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 56849 | &nbsp;&nbsp; 11545463 |
| Braze, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 332711 | &nbsp;&nbsp; 9349179 |
| Clearwater Analytics Holdings, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 719319 | &nbsp;&nbsp; 15774666 |
| CyberArk Software Ltd.<sup>(a)</sup> <br>| &nbsp;&nbsp; 52506 | &nbsp;&nbsp; 21363641 |
| Dynatrace, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 493540 | &nbsp;&nbsp; 27248343 |
| Gen Digital, Inc. | &nbsp;&nbsp; 847672 | &nbsp;&nbsp; 24921557 |
| Gitlab, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 402623 | &nbsp;&nbsp; 18162324 |
| Monday.com Ltd.<sup>(a)</sup> <br>| &nbsp;&nbsp; 81086 | &nbsp;&nbsp; 25499925 |
| SailPoint, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 99469 | &nbsp;&nbsp; 2273861 |
| Sprout Social, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 555500 | &nbsp;&nbsp; 11615505 |
| SPS Commerce, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 141318 | &nbsp;&nbsp; 19231967 |
| Varonis Systems, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 263448 | &nbsp;&nbsp; 13369986 |
| Vertex, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 442990 | &nbsp;&nbsp; 15653052 |
| Workiva, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 213700 | &nbsp;&nbsp; 14627765 |
| Zeta Global Holdings Corp., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 895992 | &nbsp;&nbsp; 13878916 |
| Zscaler, Inc.<sup>(a)</sup> <br>| &nbsp;&nbsp; 33886 | &nbsp;&nbsp; 10638171 |
| Total |  | &nbsp;&nbsp; 273328982 |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Technology Hardware, Storage & Peripherals 0.2%** | **Technology Hardware, Storage & Peripherals 0.2%** | **Technology Hardware, Storage & Peripherals 0.2%** |
| IonQ, Inc.<sup>(a),(c)</sup> <br>| &nbsp;&nbsp; 128665 | &nbsp;&nbsp; 5528735 |
| **Total Information Technology** | **Total Information Technology** | &nbsp;&nbsp; **427244264** |
| **Real Estate 2.1%** | **Real Estate 2.1%** | **Real Estate 2.1%** |
| **Real Estate Management & Development 2.1%** | **Real Estate Management & Development 2.1%** | **Real Estate Management & Development 2.1%** |
| Colliers International Group, Inc.<sup>(c)</sup> <br>| &nbsp;&nbsp; 393339 | &nbsp;&nbsp; 51346473 |
| **Total Real Estate** | **Total Real Estate** | &nbsp;&nbsp; **51346473** |
| Total Common Stocks <br>(Cost $2,086,906,229) | Total Common Stocks <br>(Cost $2,086,906,229) | &nbsp;&nbsp; **2419460562** |
| **Exchange-Traded Equity Funds 1.1%** | **Exchange-Traded Equity Funds 1.1%** | **Exchange-Traded Equity Funds 1.1%** |
|  | **Shares** | **Value ($)** |
| **Sector 1.1%** | **Sector 1.1%** | **Sector 1.1%** |
| SPDR S&P Biotech ETF<sup>(c)</sup> <br>| &nbsp;&nbsp; 324433 | &nbsp;&nbsp; 26905229 |
| Total Exchange-Traded Equity Funds <br>(Cost $26,047,989) | Total Exchange-Traded Equity Funds <br>(Cost $26,047,989) | &nbsp;&nbsp; **26905229** |
| **Money Market Funds 3.4%** | **Money Market Funds 3.4%** | **Money Market Funds 3.4%** |
| Columbia Short-Term Cash Fund, 4.473%<sup>(b),(g)</sup> <br>| &nbsp;&nbsp; 21453808 | &nbsp;&nbsp; 21449517 |
| Dreyfus Government Cash Management Fund, <br> Institutional Shares, 4.209%<sup>(g),(h)</sup> <br>| &nbsp;&nbsp; 61863077 | &nbsp;&nbsp; 61863077 |
| Total Money Market Funds <br>(Cost $83,306,343) | Total Money Market Funds <br>(Cost $83,306,343) | &nbsp;&nbsp; **83312594** |
| **Total Investments in Securities** <br>**(Cost: $2,196,260,561)** | **Total Investments in Securities** <br>**(Cost: $2,196,260,561)** | &nbsp;&nbsp; **2529678385** |
| **Other Assets & Liabilities, Net** |  | &nbsp;&nbsp; **(67944896)**<br>|
| **Net Assets** | **Net Assets** | &nbsp;&nbsp; **2461733489** |

---

**Notes to Portfolio of Investments** 

&nbsp;&nbsp;&nbsp;&nbsp;(a) Non-income producing investment.

&nbsp;&nbsp;&nbsp;&nbsp;(b) Under Section 2(a)(3) of the Investment Company Act of 1940, an affiliated company is one in which the Fund owns 5% or more of the company's outstanding voting securities, or a company which is under common ownership or control with the Fund.
 The value of the holdings and transactions in these affiliated companies during the period ended June 30, 2025 are as follows:

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Affiliated issuers** | **Beginning** <br>**of period($)**<br>| **Purchases($)** | **Sales($)** | **Net change in** <br>**unrealized** <br>**appreciation** <br>**(depreciation)($)**<br>| **End of** <br>**period($)**<br>| **Realized gain** <br>**(loss)($)**<br>| **Dividends($)** | **End of** <br>**period shares**<br>|
| Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% |
|  | 28748849 | &nbsp;&nbsp; 319720157 | &nbsp;&nbsp; (327020514)<br>| &nbsp;&nbsp; 1025 | &nbsp;&nbsp; 21449517 | &nbsp;&nbsp; 1877 | &nbsp;&nbsp; 643074 | &nbsp;&nbsp; 21453808 |
| GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A | GCM Grosvenor, Inc., Class A |
|  | 60670978 | &nbsp;&nbsp; 1799376 | &nbsp;&nbsp; — | &nbsp;&nbsp; (3646994)<br>| &nbsp;&nbsp; 58823360 | &nbsp;&nbsp; — | &nbsp;&nbsp; 1103650 | &nbsp;&nbsp; 5088526 |
| Total | 89419827 |  |  | &nbsp;&nbsp; (3645969)<br>| &nbsp;&nbsp; 80272877 | &nbsp;&nbsp; 1877 | &nbsp;&nbsp; 1746724 |  |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn<sup>®</sup> Fund, June 30, 2025 (Unaudited)

**Notes to Portfolio of Investments (continued)**

&nbsp;&nbsp;&nbsp;&nbsp;(c) All or a portion of this security was on loan at June 30, 2025. The total market value
 of securities on loan at June 30, 2025 was $60,428,091.

&nbsp;&nbsp;&nbsp;&nbsp;(d) Represents fair value as determined in good faith under procedures approved by the
 Board of Trustees. At June 30, 2025, the total value of these securities amounted to $102,062, which represents less than 0.01% of total net assets.

&nbsp;&nbsp;&nbsp;&nbsp;(e) Denotes a restricted security, which is subject to legal or contractual restrictions
 on resale under federal securities laws. Disposal of a restricted investment may involve time-consuming negotiations and expenses, and prompt sale at an acceptable
 price may be difficult to achieve. Private placement securities are generally considered to be restricted, although certain of those securities may be traded between
 qualified institutional investors under the provisions of Section 4(a)(2) and Rule 144A. The Fund will not incur any registration costs upon such a trade. These
 securities are valued at fair value determined in good faith under consistently applied procedures approved by the Fund's Board of Trustees. At June 30, 2025, the total market value of these securities amounted to $102,062, which represents less than 0.01% of total net assets. Additional information on these securities is as follows:

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Security** | **Acquisition** <br>**Dates**<br>| **Shares** | **Cost ($)** | **Value ($)** |
| DNA Script | 10/01/2021 | &nbsp;&nbsp; 1139 | &nbsp;&nbsp; 993179 | &nbsp;&nbsp; 102062 |

---

&nbsp;&nbsp;&nbsp;&nbsp;(f) Valuation based on significant unobservable inputs.

&nbsp;&nbsp;&nbsp;&nbsp;(g) The rate shown is the seven-day current annualized yield at June 30, 2025.

&nbsp;&nbsp;&nbsp;&nbsp;(h) Investment made with cash collateral received from securities lending activity.

**Abbreviation Legend** 

ADR American Depositary Receipt

**Fair value measurements** 

The Fund categorizes its fair value measurements according to a three-level hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs by prioritizing that the most observable input be used when available. Observable inputs are those that market participants would use in pricing an investment based on market data obtained from sources independent of the reporting entity. Unobservable inputs are those that reflect the Fund's assumptions about the information market participants would use in pricing an investment. An investment's level within the fair value hierarchy is based on the lowest level of any input that is deemed significant to the asset's or liability's fair value measurement. The input levels are not necessarily an indication of the risk or liquidity associated with investments at that level. For example, certain U.S. government securities are generally high quality and liquid, however, they are reflected as Level 2 because the inputs used to determine fair value may not always be quoted prices in an active market.

Fair value inputs are summarized in the three broad levels listed below:

■

Level 1 — Valuations based on quoted prices for investments in active markets that the Fund has the ability to access at the measurement date. Valuation adjustments are not applied to Level 1 investments.

■

Level 2 — Valuations based on other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risks, etc.).

■

Level 3 — Valuations based on significant unobservable inputs (including the Fund's own assumptions and judgment in determining the fair value of investments).

Inputs that are used in determining fair value of an investment may include price information, credit data, volatility statistics, and other factors. These inputs can be either observable or unobservable. The availability of observable inputs can vary between investments, and is affected by various factors such as the type of investment, and the volume and level of activity for that investment or similar investments in the marketplace. The inputs will be considered by the Investment Manager, along with any other relevant factors in the calculation of an investment's fair value. The Fund uses prices and inputs that are current as of the measurement date, which may include periods of market dislocations. During these periods, the availability of prices and inputs may be reduced for many investments. This condition could cause an investment to be reclassified between the various levels within the hierarchy.

Investments falling into the Level 3 category, if any, are primarily supported by quoted prices from brokers and dealers participating in the market for those investments. However, these may be classified as Level 3 investments due to lack of market transparency and corroboration to support these quoted prices. Additionally, valuation models may be used as the pricing source for any remaining investments classified as Level 3. These models may rely on one or more significant unobservable inputs and/or significant assumptions by the Investment Manager. Inputs used in valuations may include, but are not limited to, financial statement analysis, capital account balances, discount rates and estimated cash flows, and comparable company data.

The Fund's Board of Trustees (the Board) has designated the Investment Manager, through its Valuation Committee (the Committee), as valuation designee, responsible for determining the fair value of the assets of the Fund for which market quotations are not readily available using valuation procedures approved by the Board. The Committee consists of voting and non-voting members from various groups within the Investment Manager's organization, including operations and accounting, trading and investments, compliance, risk management and legal.

The Committee meets at least monthly to review and approve valuation matters, which may include a description of specific valuation determinations, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are or are not readily available, including recommendations of third party pricing vendors and a determination of appropriate pricing methodologies; events that require specific valuation determinations and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third party pricing vendors, including periodic reviews of vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions. Representatives of Columbia Management Investment Advisers, LLC report to the Board at each of its regularly scheduled meetings to discuss valuation matters and actions during the period, similar to those described earlier.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn<sup>®</sup> Fund, June 30, 2025 (Unaudited)

**Fair value measurements (continued)**

The following table is a summary of the inputs used to value the Fund's investments at June 30, 2025:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** | **Total ($)** |
| **Investments in Securities** |  |  |  |  |
| Common Stocks |  |  |  |  |
| Consumer Discretionary | 413611157 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 413611157 |
| Consumer Staples | 119157528 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 119157528 |
| Energy | 51135167 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 51135167 |
| Financials | 236998424 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 236998424 |
| Health Care | 492776493 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 102062 | &nbsp;&nbsp;&nbsp;&nbsp; 492878555 |
| Industrials | 627088994 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 627088994 |
| Information Technology | 427244264 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 427244264 |
| Real Estate | 51346473 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 51346473 |
| Total Common Stocks | 2419358500 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 102062 | &nbsp;&nbsp;&nbsp;&nbsp; 2419460562 |
| Exchange-Traded Equity Funds | 26905229 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 26905229 |
| Money Market Funds | 83312594 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 83312594 |
| Total Investments in Securities | 2529576323 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 102062 | &nbsp;&nbsp;&nbsp;&nbsp; 2529678385 |

---

See the Portfolio of Investments for all investment classifications not indicated in the table.

The Fund does not hold any significant investments (greater than one percent of net assets) categorized as Level 3.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments

Columbia Acorn International<sup>®</sup>, June 30, 2025 (Unaudited)

(Percentages represent value of investments compared to net assets)

**Investments in securities**

---

| | | |
|:---|:---|:---|
| **Common Stocks 99.5%** | **Common Stocks 99.5%** | **Common Stocks 99.5%** |
| **Issuer** | **Shares** | **Value ($)** |
| **Australia 3.7%** | **Australia 3.7%** | **Australia 3.7%** |
| CAR Group Ltd. | &nbsp;&nbsp; 845076 | &nbsp;&nbsp; 20811924 |
| Pro Medicus Ltd. | &nbsp;&nbsp; 70767 | &nbsp;&nbsp; 13242960 |
| **Total** | **Total** | &nbsp;&nbsp; **34054884** |
| **Canada 1.5%** | **Canada 1.5%** | **Canada 1.5%** |
| Altus Group Ltd. | &nbsp;&nbsp; 140417 | &nbsp;&nbsp; 5433135 |
| CCL Industries, Inc., Class B | &nbsp;&nbsp; 139462 | &nbsp;&nbsp; 8132680 |
| **Total** | **Total** | &nbsp;&nbsp; **13565815** |
| **China 1.5%** | **China 1.5%** | **China 1.5%** |
| Silergy Corp. | &nbsp;&nbsp; 1138000 | &nbsp;&nbsp; 13862245 |
| **Finland 2.7%** | **Finland 2.7%** | **Finland 2.7%** |
| Konecranes OYJ | &nbsp;&nbsp; 119353 | &nbsp;&nbsp; 9483995 |
| Valmet OYJ | &nbsp;&nbsp; 504309 | &nbsp;&nbsp; 15629543 |
| **Total** | **Total** | &nbsp;&nbsp; **25113538** |
| **France 3.1%** | **France 3.1%** | **France 3.1%** |
| Gaztransport Et Technigaz SA | &nbsp;&nbsp; 63347 | &nbsp;&nbsp; 12531509 |
| Robertet SA | &nbsp;&nbsp; 5645 | &nbsp;&nbsp; 5293150 |
| Virbac SA | &nbsp;&nbsp; 28216 | &nbsp;&nbsp; 10620929 |
| **Total** | **Total** | &nbsp;&nbsp; **28445588** |
| **Germany 8.2%** | **Germany 8.2%** | **Germany 8.2%** |
| Atoss Software SE | &nbsp;&nbsp; 76237 | &nbsp;&nbsp; 12675580 |
| CTS Eventim AG & Co. KGaA | &nbsp;&nbsp; 194181 | &nbsp;&nbsp; 24146540 |
| Hypoport SE<sup>(a)</sup> <br>| &nbsp;&nbsp; 74680 | &nbsp;&nbsp; 17789215 |
| Nemetschek SE | &nbsp;&nbsp; 146401 | &nbsp;&nbsp; 21227094 |
| **Total** | **Total** | &nbsp;&nbsp; **75838429** |
| **India 0.8%** | **India 0.8%** | **India 0.8%** |
| Max Healthcare Institute Ltd. | &nbsp;&nbsp; 530796 | &nbsp;&nbsp; 7897571 |
| **Ireland 1.9%** | **Ireland 1.9%** | **Ireland 1.9%** |
| Bank of Ireland Group PLC | &nbsp;&nbsp; 1264765 | &nbsp;&nbsp; 18023060 |
| **Italy 2.0%** | **Italy 2.0%** | **Italy 2.0%** |
| Amplifon SpA | &nbsp;&nbsp; 505218 | &nbsp;&nbsp; 11865456 |
| Carel Industries SpA | &nbsp;&nbsp; 241694 | &nbsp;&nbsp; 6442660 |
| **Total** | **Total** | &nbsp;&nbsp; **18308116** |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Japan 34.1%** | **Japan 34.1%** | **Japan 34.1%** |
| Capcom Co., Ltd. | &nbsp;&nbsp; 862500 | &nbsp;&nbsp; 29455664 |
| Disco Corp. | &nbsp;&nbsp; 57700 | &nbsp;&nbsp; 17093246 |
| Gunma Bank Ltd. (The) | &nbsp;&nbsp; 1030400 | &nbsp;&nbsp; 8648946 |
| Kakaku.com, Inc. | &nbsp;&nbsp; 847000 | &nbsp;&nbsp; 15706888 |
| Kokusai Electric Corp. | &nbsp;&nbsp; 587400 | &nbsp;&nbsp; 14055031 |
| Kyoritsu Maintenance Co., Ltd. | &nbsp;&nbsp; 408800 | &nbsp;&nbsp; 9979995 |
| Kyudenko Corp. | &nbsp;&nbsp; 304200 | &nbsp;&nbsp; 12585593 |
| Macnica Holdings, Inc. | &nbsp;&nbsp; 325400 | &nbsp;&nbsp; 4365600 |
| MatsukiyoCocokara & Co. | &nbsp;&nbsp; 397500 | &nbsp;&nbsp; 8176784 |
| Nippon Sanso Holdings Corp. | &nbsp;&nbsp; 481100 | &nbsp;&nbsp; 18205550 |
| Nissin Foods Holdings Co., Ltd. | &nbsp;&nbsp; 363100 | &nbsp;&nbsp; 7543458 |
| Niterra Co., Ltd. | &nbsp;&nbsp; 654200 | &nbsp;&nbsp; 21751057 |
| Nomura Real Estate Holdings, Inc. | &nbsp;&nbsp; 2734500 | &nbsp;&nbsp; 16016567 |
| Obic Co., Ltd. | &nbsp;&nbsp; 414500 | &nbsp;&nbsp; 16117863 |
| Omron Corp. | &nbsp;&nbsp; 409300 | &nbsp;&nbsp; 11033275 |
| Recruit Holdings Co., Ltd. | &nbsp;&nbsp; 181400 | &nbsp;&nbsp; 10667524 |
| Sanwa Holdings Corp. | &nbsp;&nbsp; 400700 | &nbsp;&nbsp; 13289476 |
| Sekisui Chemical Co., Ltd. | &nbsp;&nbsp; 720000 | &nbsp;&nbsp; 13039692 |
| Simplex Holdings, Inc. | &nbsp;&nbsp; 700300 | &nbsp;&nbsp; 18947547 |
| Sundrug Co., Ltd. | &nbsp;&nbsp; 177000 | &nbsp;&nbsp; 5539187 |
| Suntory Beverage & Food Ltd. | &nbsp;&nbsp; 595100 | &nbsp;&nbsp; 19030966 |
| Taisei Corp. | &nbsp;&nbsp; 276700 | &nbsp;&nbsp; 16115160 |
| Yaskawa Electric Corp. | &nbsp;&nbsp; 354900 | &nbsp;&nbsp; 8025427 |
| **Total** | **Total** | &nbsp;&nbsp; **315390496** |
| **Mexico 1.8%** | **Mexico 1.8%** | **Mexico 1.8%** |
| Corporación Inmobiliaria Vesta SAB de CV | &nbsp;&nbsp; 5949523 | &nbsp;&nbsp; 16369947 |
| **Netherlands 3.6%** | **Netherlands 3.6%** | **Netherlands 3.6%** |
| BE Semiconductor Industries NV | &nbsp;&nbsp; 108708 | &nbsp;&nbsp; 16257646 |
| IMCD NV | &nbsp;&nbsp; 129332 | &nbsp;&nbsp; 17394555 |
| **Total** | **Total** | &nbsp;&nbsp; **33652201** |
| **New Zealand 2.6%** | **New Zealand 2.6%** | **New Zealand 2.6%** |
| Fisher & Paykel Healthcare Corp., Ltd. | &nbsp;&nbsp; 1101702 | &nbsp;&nbsp; 24198584 |
| **Spain 1.4%** | **Spain 1.4%** | **Spain 1.4%** |
| Viscofan SA | &nbsp;&nbsp; 177979 | &nbsp;&nbsp; 12660122 |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn International<sup>®</sup>, June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Sweden 4.3%** | **Sweden 4.3%** | **Sweden 4.3%** |
| AddTech AB, B Shares | &nbsp;&nbsp; 315479 | &nbsp;&nbsp; 10755170 |
| Hexagon AB, Class B | &nbsp;&nbsp; 1648513 | &nbsp;&nbsp; 16616349 |
| Munters Group AB | &nbsp;&nbsp; 478905 | &nbsp;&nbsp; 7018500 |
| Thule Group AB | &nbsp;&nbsp; 208458 | &nbsp;&nbsp; 6004374 |
| **Total** | **Total** | &nbsp;&nbsp; **40394393** |
| **Switzerland 5.2%** | **Switzerland 5.2%** | **Switzerland 5.2%** |
| Belimo Holding AG, Registered Shares | &nbsp;&nbsp; 20795 | &nbsp;&nbsp; 21196389 |
| Inficon Holding AG, Registered Shares | &nbsp;&nbsp; 82514 | &nbsp;&nbsp; 11082203 |
| Kardex Holding AG | &nbsp;&nbsp; 22469 | &nbsp;&nbsp; 7814918 |
| VAT Group AG | &nbsp;&nbsp; 19160 | &nbsp;&nbsp; 8118709 |
| **Total** | **Total** | &nbsp;&nbsp; **48212219** |
| **United Kingdom 17.8%** | **United Kingdom 17.8%** | **United Kingdom 17.8%** |
| Ashtead Group PLC | &nbsp;&nbsp; 196308 | &nbsp;&nbsp; 12588460 |
| Auto Trader Group PLC | &nbsp;&nbsp; 2046313 | &nbsp;&nbsp; 23178170 |
| Baltic Classifieds Group PLC | &nbsp;&nbsp; 1469849 | &nbsp;&nbsp; 7525604 |
| ConvaTec Group PLC | &nbsp;&nbsp; 5024691 | &nbsp;&nbsp; 19903042 |
| Genus PLC | &nbsp;&nbsp; 218899 | &nbsp;&nbsp; 6147209 |
| Halma PLC | &nbsp;&nbsp; 595605 | &nbsp;&nbsp; 26179296 |
| Howden Joinery Group PLC | &nbsp;&nbsp; 1131973 | &nbsp;&nbsp; 13311456 |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| Intermediate Capital Group PLC | &nbsp;&nbsp; 784412 | &nbsp;&nbsp; 20807234 |
| Rightmove PLC | &nbsp;&nbsp; 2274199 | &nbsp;&nbsp; 24614616 |
| Safestore Holdings PLC | &nbsp;&nbsp; 1099285 | &nbsp;&nbsp; 10683249 |
| **Total** | **Total** | &nbsp;&nbsp; **164938336** |
| **United States 3.3%** | **United States 3.3%** | **United States 3.3%** |
| CRH PLC | &nbsp;&nbsp; 138047 | &nbsp;&nbsp; 12743079 |
| Interparfums, Inc. | &nbsp;&nbsp; 134837 | &nbsp;&nbsp; 17705447 |
| **Total** | **Total** | &nbsp;&nbsp; **30448526** |
| Total Common Stocks <br>(Cost $625,399,297) | Total Common Stocks <br>(Cost $625,399,297) | &nbsp;&nbsp; **921374070** |
| **Money Market Funds 0.5%** | **Money Market Funds 0.5%** | **Money Market Funds 0.5%** |
|  | **Shares** | **Value ($)** |
| Columbia Short-Term Cash Fund, 4.473%<sup>(b),(c)</sup> <br>| &nbsp;&nbsp; 4104225 | &nbsp;&nbsp; 4103404 |
| Total Money Market Funds <br>(Cost $4,102,999) | Total Money Market Funds <br>(Cost $4,102,999) | &nbsp;&nbsp; **4103404** |
| **Total Investments in Securities** <br>**(Cost $629,502,296)** | **Total Investments in Securities** <br>**(Cost $629,502,296)** | &nbsp;&nbsp; **925477474** |
| **Other Assets & Liabilities, Net** |  | &nbsp;&nbsp; **202586** |
| **Net Assets** | **Net Assets** | &nbsp;&nbsp; **$925680060** |

---

**Notes to Portfolio of Investments** 

&nbsp;&nbsp;&nbsp;&nbsp;(a) Non-income producing investment.

&nbsp;&nbsp;&nbsp;&nbsp;(b) The rate shown is the seven-day current annualized yield at June 30, 2025.

&nbsp;&nbsp;&nbsp;&nbsp;(c) Under Section 2(a)(3) of the Investment Company Act of 1940, an affiliated company is one in which the Fund owns 5% or more of the company's outstanding voting securities, or a company which is under common ownership or control with the Fund.
 The value of the holdings and transactions in these affiliated companies during the period ended June 30, 2025 are as follows:

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Affiliated issuers** | **Beginning** <br>**of period($)**<br>| **Purchases($)** | **Sales($)** | **Net change in** <br>**unrealized** <br>**appreciation** <br>**(depreciation)($)**<br>| **End of** <br>**period($)**<br>| **Realized gain** <br>**(loss)($)**<br>| **Dividends($)** | **End of** <br>**period shares**<br>|
| Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% |
|  | 3715484 | &nbsp;&nbsp; 92481960 | &nbsp;&nbsp; (92094445)<br>| &nbsp;&nbsp; 405 | &nbsp;&nbsp; 4103404 | &nbsp;&nbsp; (2511)<br>| &nbsp;&nbsp; 135239 | &nbsp;&nbsp; 4104225 |

---

**Fair value measurements** 

The Fund categorizes its fair value measurements according to a three-level hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs by prioritizing that the most observable input be used when available. Observable inputs are those that market participants would use in pricing an investment based on market data obtained from sources independent of the reporting entity. Unobservable inputs are those that reflect the Fund's assumptions about the information market participants would use in pricing an investment. An investment's level within the fair value hierarchy is based on the lowest level of any input that is deemed significant to the asset's or liability's fair value measurement. The input levels are not necessarily an indication of the risk or liquidity associated with investments at that level. For example, certain U.S. government securities are generally high quality and liquid, however, they are reflected as Level 2 because the inputs used to determine fair value may not always be quoted prices in an active market.

Fair value inputs are summarized in the three broad levels listed below:

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn International<sup>®</sup>, June 30, 2025 (Unaudited)

**Fair value measurements (continued)**

■

Level 1 — Valuations based on quoted prices for investments in active markets that the Fund has the ability to access at the measurement date. Valuation adjustments are not applied to Level 1 investments.

■

Level 2 — Valuations based on other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risks, etc.).

■

Level 3 — Valuations based on significant unobservable inputs (including the Fund's own assumptions and judgment in determining the fair value of investments).

Inputs that are used in determining fair value of an investment may include price information, credit data, volatility statistics, and other factors. These inputs can be either observable or unobservable. The availability of observable inputs can vary between investments, and is affected by various factors such as the type of investment, and the volume and level of activity for that investment or similar investments in the marketplace. The inputs will be considered by the Investment Manager, along with any other relevant factors in the calculation of an investment's fair value. The Fund uses prices and inputs that are current as of the measurement date, which may include periods of market dislocations. During these periods, the availability of prices and inputs may be reduced for many investments. This condition could cause an investment to be reclassified between the various levels within the hierarchy.

Values of foreign equity securities actively traded in markets where there is a significant delay in the local close relative to the New York Stock Exchange may include an adjustment to reflect the impact of market movements following the close of local trading, as described in Note 2 to the financial statements – Security valuation. When such adjustments have been made, the foreign equity securities are classified as Level 2.

Investments falling into the Level 3 category, if any, are primarily supported by quoted prices from brokers and dealers participating in the market for those investments. However, these may be classified as Level 3 investments due to lack of market transparency and corroboration to support these quoted prices. Additionally, valuation models may be used as the pricing source for any remaining investments classified as Level 3. These models may rely on one or more significant unobservable inputs and/or significant assumptions by the Investment Manager. Inputs used in valuations may include, but are not limited to, financial statement analysis, capital account balances, discount rates and estimated cash flows, and comparable company data.

The Fund's Board of Trustees (the Board) has designated the Investment Manager, through its Valuation Committee (the Committee), as valuation designee, responsible for determining the fair value of the assets of the Fund for which market quotations are not readily available using valuation procedures approved by the Board. The Committee consists of voting and non-voting members from various groups within the Investment Manager's organization, including operations and accounting, trading and investments, compliance, risk management and legal.

The Committee meets at least monthly to review and approve valuation matters, which may include a description of specific valuation determinations, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are or are not readily available, including recommendations of third party pricing vendors and a determination of appropriate pricing methodologies; events that require specific valuation determinations and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third party pricing vendors, including periodic reviews of vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions. Representatives of Columbia Management Investment Advisers, LLC report to the Board at each of its regularly scheduled meetings to discuss valuation matters and actions during the period, similar to those described earlier.

The following table is a summary of the inputs used to value the Fund's investments at June 30, 2025:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** | **Total ($)** |
| **Investments in Securities** |  |  |  |  |
| Common Stocks |  |  |  |  |
| Australia |  | &nbsp;&nbsp;&nbsp;&nbsp; 34054884 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 34054884 |
| Canada | 13565815 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 13565815 |
| China |  | &nbsp;&nbsp;&nbsp;&nbsp; 13862245 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 13862245 |
| Finland |  | &nbsp;&nbsp;&nbsp;&nbsp; 25113538 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 25113538 |
| France |  | &nbsp;&nbsp;&nbsp;&nbsp; 28445588 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 28445588 |
| Germany |  | &nbsp;&nbsp;&nbsp;&nbsp; 75838429 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 75838429 |
| India | 7897571 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 7897571 |
| Ireland |  | &nbsp;&nbsp;&nbsp;&nbsp; 18023060 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 18023060 |
| Italy |  | &nbsp;&nbsp;&nbsp;&nbsp; 18308116 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 18308116 |
| Japan |  | &nbsp;&nbsp;&nbsp;&nbsp; 315390496 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 315390496 |
| Mexico | 16369947 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 16369947 |
| Netherlands |  | &nbsp;&nbsp;&nbsp;&nbsp; 33652201 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 33652201 |
| New Zealand |  | &nbsp;&nbsp;&nbsp;&nbsp; 24198584 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 24198584 |
| Spain |  | &nbsp;&nbsp;&nbsp;&nbsp; 12660122 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 12660122 |
| Sweden |  | &nbsp;&nbsp;&nbsp;&nbsp; 40394393 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 40394393 |
| Switzerland |  | &nbsp;&nbsp;&nbsp;&nbsp; 48212219 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 48212219 |
| United Kingdom | 18208853 | &nbsp;&nbsp;&nbsp;&nbsp; 146729483 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 164938336 |
| United States | 17705447 | &nbsp;&nbsp;&nbsp;&nbsp; 12743079 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 30448526 |
| Total Common Stocks | 73747633 | &nbsp;&nbsp;&nbsp;&nbsp; 847626437 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 921374070 |
| Money Market Funds | 4103404 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 4103404 |
| Total Investments in Securities | 77851037 | &nbsp;&nbsp;&nbsp;&nbsp; 847626437 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 925477474 |

---

See the Portfolio of Investments for all investment classifications not indicated in the table.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn International<sup>®</sup>, June 30, 2025 (Unaudited)

**Fair value measurements (continued)**

The Fund's assets assigned to the Level 2 input category are generally valued using the market approach, in which a security's value is determined through reference to prices and information from market transactions for similar or identical assets. These assets include certain foreign securities for which a third party statistical pricing service may be employed for purposes of fair market valuation. The model utilized by such third party statistical pricing service takes into account a security's correlation to available market data including relevant general and sector indices, currency fluctuations, depositary receipts, and futures, as applicable.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments

Columbia Acorn International Select<sup>SM</sup>, June 30, 2025 (Unaudited)

(Percentages represent value of investments compared to net assets)

**Investments in securities**

---

| | | |
|:---|:---|:---|
| **Common Stocks 98.9%** | **Common Stocks 98.9%** | **Common Stocks 98.9%** |
| **Issuer** | **Shares** | **Value ($)** |
| **Australia 1.5%** | **Australia 1.5%** | **Australia 1.5%** |
| CSL Ltd. | &nbsp;&nbsp; 19170 | &nbsp;&nbsp; 3028105 |
| **Canada 0.7%** | **Canada 0.7%** | **Canada 0.7%** |
| Shopify, Inc., Class A<sup>(a)</sup> <br>| &nbsp;&nbsp; 11780 | &nbsp;&nbsp; 1358669 |
| **Denmark 2.0%** | **Denmark 2.0%** | **Denmark 2.0%** |
| Novo Nordisk A/S, Class B | &nbsp;&nbsp; 59175 | &nbsp;&nbsp; 4100475 |
| **Finland 0.5%** | **Finland 0.5%** | **Finland 0.5%** |
| Konecranes OYJ | &nbsp;&nbsp; 13075 | &nbsp;&nbsp; 1038962 |
| **France 15.9%** | **France 15.9%** | **France 15.9%** |
| Airbus Group SE | &nbsp;&nbsp; 26349 | &nbsp;&nbsp; 5512230 |
| Cie de Saint-Gobain SA | &nbsp;&nbsp; 22488 | &nbsp;&nbsp; 2641783 |
| EssilorLuxottica SA | &nbsp;&nbsp; 11484 | &nbsp;&nbsp; 3153421 |
| L'Oreal SA | &nbsp;&nbsp; 6884 | &nbsp;&nbsp; 2948786 |
| LVMH Moet Hennessy Louis Vuitton SE | &nbsp;&nbsp; 6971 | &nbsp;&nbsp; 3648482 |
| Publicis Groupe SA | &nbsp;&nbsp; 44604 | &nbsp;&nbsp; 5037788 |
| Schneider Electric SE | &nbsp;&nbsp; 29845 | &nbsp;&nbsp; 8012932 |
| TotalEnergies SE | &nbsp;&nbsp; 21939 | &nbsp;&nbsp; 1340970 |
| **Total** | **Total** | &nbsp;&nbsp; **32296392** |
| **Germany 8.5%** | **Germany 8.5%** | **Germany 8.5%** |
| Adidas AG | &nbsp;&nbsp; 22562 | &nbsp;&nbsp; 5266646 |
| Deutsche Telekom AG, Registered Shares | &nbsp;&nbsp; 123264 | &nbsp;&nbsp; 4511906 |
| Nemetschek SE | &nbsp;&nbsp; 25067 | &nbsp;&nbsp; 3634535 |
| SAP SE | &nbsp;&nbsp; 12455 | &nbsp;&nbsp; 3808483 |
| **Total** | **Total** | &nbsp;&nbsp; **17221570** |
| **India 2.2%** | **India 2.2%** | **India 2.2%** |
| Max Healthcare Institute Ltd. | &nbsp;&nbsp; 119375 | &nbsp;&nbsp; 1776149 |
| Phoenix Mills Ltd. (The) | &nbsp;&nbsp; 144502 | &nbsp;&nbsp; 2632608 |
| **Total** | **Total** | &nbsp;&nbsp; **4408757** |
| **Ireland 2.7%** | **Ireland 2.7%** | **Ireland 2.7%** |
| Bank of Ireland Group PLC | &nbsp;&nbsp; 381479 | &nbsp;&nbsp; 5436124 |
| **Japan 27.1%** | **Japan 27.1%** | **Japan 27.1%** |
| Capcom Co., Ltd. | &nbsp;&nbsp; 232600 | &nbsp;&nbsp; 7943637 |
| Daikin Industries Ltd. | &nbsp;&nbsp; 20000 | &nbsp;&nbsp; 2347675 |
| Disco Corp. | &nbsp;&nbsp; 12700 | &nbsp;&nbsp; 3762292 |
| Gunma Bank Ltd. (The) | &nbsp;&nbsp; 335300 | &nbsp;&nbsp; 2814433 |
| Kokusai Electric Corp. | &nbsp;&nbsp; 100600 | &nbsp;&nbsp; 2407109 |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| MatsukiyoCocokara & Co. | &nbsp;&nbsp; 117200 | &nbsp;&nbsp; 2410866 |
| Niterra Co., Ltd. | &nbsp;&nbsp; 98300 | &nbsp;&nbsp; 3268311 |
| Nomura Real Estate Holdings, Inc. | &nbsp;&nbsp; 322000 | &nbsp;&nbsp; 1886025 |
| Omron Corp. | &nbsp;&nbsp; 98800 | &nbsp;&nbsp; 2663297 |
| ORIX Corp. | &nbsp;&nbsp; 136100 | &nbsp;&nbsp; 3071325 |
| Recruit Holdings Co., Ltd. | &nbsp;&nbsp; 59500 | &nbsp;&nbsp; 3498995 |
| Shimadzu Corp. | &nbsp;&nbsp; 54900 | &nbsp;&nbsp; 1357293 |
| Sony Group Corp. | &nbsp;&nbsp; 166500 | &nbsp;&nbsp; 4329054 |
| Suntory Beverage & Food Ltd. | &nbsp;&nbsp; 125800 | &nbsp;&nbsp; 4023014 |
| Taisei Corp. | &nbsp;&nbsp; 69400 | &nbsp;&nbsp; 4041894 |
| Tokyo Electron Ltd. | &nbsp;&nbsp; 18400 | &nbsp;&nbsp; 3523774 |
| Yaskawa Electric Corp. | &nbsp;&nbsp; 80700 | &nbsp;&nbsp; 1824886 |
| **Total** | **Total** | &nbsp;&nbsp; **55173880** |
| **Netherlands 3.6%** | **Netherlands 3.6%** | **Netherlands 3.6%** |
| ASML Holding NV | &nbsp;&nbsp; 6671 | &nbsp;&nbsp; 5345718 |
| IMCD NV | &nbsp;&nbsp; 14131 | &nbsp;&nbsp; 1900554 |
| **Total** | **Total** | &nbsp;&nbsp; **7246272** |
| **New Zealand 1.6%** | **New Zealand 1.6%** | **New Zealand 1.6%** |
| Fisher & Paykel Healthcare Corp., Ltd. | &nbsp;&nbsp; 148045 | &nbsp;&nbsp; 3251768 |
| **Singapore 1.7%** | **Singapore 1.7%** | **Singapore 1.7%** |
| DBS Group Holdings Ltd. | &nbsp;&nbsp; 97790 | &nbsp;&nbsp; 3452191 |
| **Spain 1.9%** | **Spain 1.9%** | **Spain 1.9%** |
| Industria de Diseno Textil SA | &nbsp;&nbsp; 75631 | &nbsp;&nbsp; 3945424 |
| **Switzerland 7.1%** | **Switzerland 7.1%** | **Switzerland 7.1%** |
| Belimo Holding AG, Registered Shares | &nbsp;&nbsp; 3475 | &nbsp;&nbsp; 3542075 |
| Lonza Group AG, Registered Shares | &nbsp;&nbsp; 5084 | &nbsp;&nbsp; 3635891 |
| Nestlé SA, Registered Shares | &nbsp;&nbsp; 46461 | &nbsp;&nbsp; 4619449 |
| VAT Group AG | &nbsp;&nbsp; 6447 | &nbsp;&nbsp; 2731801 |
| **Total** | **Total** | &nbsp;&nbsp; **14529216** |
| **United Kingdom 20.3%** | **United Kingdom 20.3%** | **United Kingdom 20.3%** |
| 3i Group PLC | &nbsp;&nbsp; 115540 | &nbsp;&nbsp; 6538664 |
| Ashtead Group PLC | &nbsp;&nbsp; 38222 | &nbsp;&nbsp; 2451027 |
| Auto Trader Group PLC | &nbsp;&nbsp; 177233 | &nbsp;&nbsp; 2007482 |
| BT Group PLC | &nbsp;&nbsp; 1857140 | &nbsp;&nbsp; 4945049 |
| ConvaTec Group PLC | &nbsp;&nbsp; 882123 | &nbsp;&nbsp; 3494131 |
| Halma PLC | &nbsp;&nbsp; 76902 | &nbsp;&nbsp; 3380160 |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn International Select<sup>SM</sup>, June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| Howden Joinery Group PLC | &nbsp;&nbsp; 285015 | &nbsp;&nbsp; 3351639 |
| Intermediate Capital Group PLC | &nbsp;&nbsp; 150106 | &nbsp;&nbsp; 3981697 |
| London Stock Exchange Group PLC | &nbsp;&nbsp; 29163 | &nbsp;&nbsp; 4265008 |
| Reckitt Benckiser Group PLC | &nbsp;&nbsp; 44362 | &nbsp;&nbsp; 3022250 |
| Rightmove PLC | &nbsp;&nbsp; 235662 | &nbsp;&nbsp; 2550669 |
| Rio Tinto PLC | &nbsp;&nbsp; 23486 | &nbsp;&nbsp; 1366982 |
| **Total** | **Total** | &nbsp;&nbsp; **41354758** |
| **United States 1.6%** | **United States 1.6%** | **United States 1.6%** |
| CRH PLC | &nbsp;&nbsp; 36450 | &nbsp;&nbsp; 3364689 |
| Total Common Stocks <br>(Cost $160,468,969) | Total Common Stocks <br>(Cost $160,468,969) | &nbsp;&nbsp; **201207252** |

---

---

| | | |
|:---|:---|:---|
| **Money Market Funds 0.8%** | **Money Market Funds 0.8%** | **Money Market Funds 0.8%** |
|  | **Shares** | **Value ($)** |
| Columbia Short-Term Cash Fund, 4.473%<sup>(b),(c)</sup> <br>| &nbsp;&nbsp; 1674643 | &nbsp;&nbsp; 1674308 |
| Total Money Market Funds <br>(Cost $1,674,211) | Total Money Market Funds <br>(Cost $1,674,211) | &nbsp;&nbsp; **1674308** |
| **Total Investments in Securities** <br>**(Cost $162,143,180)** | **Total Investments in Securities** <br>**(Cost $162,143,180)** | &nbsp;&nbsp; **202881560** |
| **Other Assets & Liabilities, Net** |  | &nbsp;&nbsp; **639455** |
| **Net Assets** | **Net Assets** | &nbsp;&nbsp; **$203521015** |

---

**Notes to Portfolio of Investments** 

&nbsp;&nbsp;&nbsp;&nbsp;(a) Non-income producing investment.

&nbsp;&nbsp;&nbsp;&nbsp;(b) The rate shown is the seven-day current annualized yield at June 30, 2025.

&nbsp;&nbsp;&nbsp;&nbsp;(c) Under Section 2(a)(3) of the Investment Company Act of 1940, an affiliated company is one in which the Fund owns 5% or more of the company's outstanding voting securities, or a company which is under common ownership or control with the Fund.
 The value of the holdings and transactions in these affiliated companies during the period ended June 30, 2025 are as follows:

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Affiliated issuers** | **Beginning** <br>**of period($)**<br>| **Purchases($)** | **Sales($)** | **Net change in** <br>**unrealized** <br>**appreciation** <br>**(depreciation)($)**<br>| **End of** <br>**period($)**<br>| **Realized gain** <br>**(loss)($)**<br>| **Dividends($)** | **End of** <br>**period shares**<br>|
| Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% |
|  | 2828723 | &nbsp;&nbsp; 15626953 | &nbsp;&nbsp; (16781266)<br>| &nbsp;&nbsp; (102)<br>| &nbsp;&nbsp; 1674308 | &nbsp;&nbsp; 685 | &nbsp;&nbsp; 50294 | &nbsp;&nbsp; 1674643 |

---

**Fair value measurements** 

The Fund categorizes its fair value measurements according to a three-level hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs by prioritizing that the most observable input be used when available. Observable inputs are those that market participants would use in pricing an investment based on market data obtained from sources independent of the reporting entity. Unobservable inputs are those that reflect the Fund's assumptions about the information market participants would use in pricing an investment. An investment's level within the fair value hierarchy is based on the lowest level of any input that is deemed significant to the asset's or liability's fair value measurement. The input levels are not necessarily an indication of the risk or liquidity associated with investments at that level. For example, certain U.S. government securities are generally high quality and liquid, however, they are reflected as Level 2 because the inputs used to determine fair value may not always be quoted prices in an active market.

Fair value inputs are summarized in the three broad levels listed below:

■

Level 1 — Valuations based on quoted prices for investments in active markets that the Fund has the ability to access at the measurement date. Valuation adjustments are not applied to Level 1 investments.

■

Level 2 — Valuations based on other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risks, etc.).

■

Level 3 — Valuations based on significant unobservable inputs (including the Fund's own assumptions and judgment in determining the fair value of investments).

Inputs that are used in determining fair value of an investment may include price information, credit data, volatility statistics, and other factors. These inputs can be either observable or unobservable. The availability of observable inputs can vary between investments, and is affected by various factors such as the type of investment, and the volume and level of activity for that investment or similar investments in the marketplace. The inputs will be considered by the Investment Manager, along with any other relevant factors in the calculation of an investment's fair value. The Fund uses prices and inputs that are current as of the measurement date, which may include periods of market dislocations. During these periods, the availability of prices and inputs may be reduced for many investments. This condition could cause an investment to be reclassified between the various levels within the hierarchy.

Values of foreign equity securities actively traded in markets where there is a significant delay in the local close relative to the New York Stock Exchange may include an adjustment to reflect the impact of market movements following the close of local trading, as described in Note 2 to the financial statements – Security valuation. When such adjustments have been made, the foreign equity securities are classified as Level 2.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn International Select<sup>SM</sup>, June 30, 2025 (Unaudited)

**Fair value measurements (continued)**

Investments falling into the Level 3 category, if any, are primarily supported by quoted prices from brokers and dealers participating in the market for those investments. However, these may be classified as Level 3 investments due to lack of market transparency and corroboration to support these quoted prices. Additionally, valuation models may be used as the pricing source for any remaining investments classified as Level 3. These models may rely on one or more significant unobservable inputs and/or significant assumptions by the Investment Manager. Inputs used in valuations may include, but are not limited to, financial statement analysis, capital account balances, discount rates and estimated cash flows, and comparable company data.

The Fund's Board of Trustees (the Board) has designated the Investment Manager, through its Valuation Committee (the Committee), as valuation designee, responsible for determining the fair value of the assets of the Fund for which market quotations are not readily available using valuation procedures approved by the Board. The Committee consists of voting and non-voting members from various groups within the Investment Manager's organization, including operations and accounting, trading and investments, compliance, risk management and legal.

The Committee meets at least monthly to review and approve valuation matters, which may include a description of specific valuation determinations, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are or are not readily available, including recommendations of third party pricing vendors and a determination of appropriate pricing methodologies; events that require specific valuation determinations and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third party pricing vendors, including periodic reviews of vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions. Representatives of Columbia Management Investment Advisers, LLC report to the Board at each of its regularly scheduled meetings to discuss valuation matters and actions during the period, similar to those described earlier.

The following table is a summary of the inputs used to value the Fund's investments at June 30, 2025:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** | **Total ($)** |
| **Investments in Securities** |  |  |  |  |
| Common Stocks |  |  |  |  |
| Australia |  | &nbsp;&nbsp;&nbsp;&nbsp; 3028105 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3028105 |
| Canada | 1358669 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1358669 |
| Denmark |  | &nbsp;&nbsp;&nbsp;&nbsp; 4100475 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 4100475 |
| Finland |  | &nbsp;&nbsp;&nbsp;&nbsp; 1038962 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1038962 |
| France |  | &nbsp;&nbsp;&nbsp;&nbsp; 32296392 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 32296392 |
| Germany |  | &nbsp;&nbsp;&nbsp;&nbsp; 17221570 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 17221570 |
| India | 1776149 | &nbsp;&nbsp;&nbsp;&nbsp; 2632608 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 4408757 |
| Ireland |  | &nbsp;&nbsp;&nbsp;&nbsp; 5436124 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 5436124 |
| Japan |  | &nbsp;&nbsp;&nbsp;&nbsp; 55173880 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 55173880 |
| Netherlands |  | &nbsp;&nbsp;&nbsp;&nbsp; 7246272 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 7246272 |
| New Zealand |  | &nbsp;&nbsp;&nbsp;&nbsp; 3251768 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3251768 |
| Singapore |  | &nbsp;&nbsp;&nbsp;&nbsp; 3452191 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3452191 |
| Spain |  | &nbsp;&nbsp;&nbsp;&nbsp; 3945424 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3945424 |
| Switzerland |  | &nbsp;&nbsp;&nbsp;&nbsp; 14529216 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 14529216 |
| United Kingdom |  | &nbsp;&nbsp;&nbsp;&nbsp; 41354758 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 41354758 |
| United States |  | &nbsp;&nbsp;&nbsp;&nbsp; 3364689 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3364689 |
| Total Common Stocks | 3134818 | &nbsp;&nbsp;&nbsp;&nbsp; 198072434 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 201207252 |
| Money Market Funds | 1674308 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1674308 |
| Total Investments in Securities | 4809126 | &nbsp;&nbsp;&nbsp;&nbsp; 198072434 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 202881560 |

---

See the Portfolio of Investments for all investment classifications not indicated in the table.

The Fund's assets assigned to the Level 2 input category are generally valued using the market approach, in which a security's value is determined through reference to prices and information from market transactions for similar or identical assets. These assets include certain foreign securities for which a third party statistical pricing service may be employed for purposes of fair market valuation. The model utilized by such third party statistical pricing service takes into account a security's correlation to available market data including relevant general and sector indices, currency fluctuations, depositary receipts, and futures, as applicable.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments

Columbia Thermostat Fund<sup>SM</sup>, June 30, 2025 (Unaudited)

(Percentages represent value of investments compared to net assets)

**Investments in securities**

---

| | | |
|:---|:---|:---|
| **Equity Funds 32.1%** | **Equity Funds 32.1%** | **Equity Funds 32.1%** |
|  | **Shares** | **Value ($)** |
| **U.S. Large Cap 32.1%** | **U.S. Large Cap 32.1%** | **U.S. Large Cap 32.1%** |
| Columbia Contrarian Core Fund, Institutional 3 <br> Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 3234272 | &nbsp;&nbsp; 125489769 |
| Columbia Large Cap Enhanced Core Fund, <br> Institutional 3 Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 4496052 | &nbsp;&nbsp; 124810396 |
| Columbia Large Cap Growth Fund, Institutional 3 <br> Class<sup>(a),(b)</sup> <br>| &nbsp;&nbsp; 622897 | &nbsp;&nbsp; 50448411 |
| Columbia Large Cap Index Fund, Institutional 3 <br> Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 1853125 | &nbsp;&nbsp; 100439401 |
| **Total** | **Total** | &nbsp;&nbsp; **401187977** |
| Total Equity Funds <br>(Cost $331,878,548) | Total Equity Funds <br>(Cost $331,878,548) | &nbsp;&nbsp; **401187977** |
| **Exchange-Traded Equity Funds 8.1%** | **Exchange-Traded Equity Funds 8.1%** | **Exchange-Traded Equity Funds 8.1%** |
| **U.S. Large Cap 8.1%** | **U.S. Large Cap 8.1%** | **U.S. Large Cap 8.1%** |
| Columbia Research Enhanced Core ETF<sup>(a)</sup> <br>| &nbsp;&nbsp; 2732920 | &nbsp;&nbsp; 100544127 |
| Total Exchange-Traded Equity Funds <br>(Cost $83,660,551) | Total Exchange-Traded Equity Funds <br>(Cost $83,660,551) | &nbsp;&nbsp; **100544127** |
| **Exchange-Traded Fixed Income Funds 6.0%** | **Exchange-Traded Fixed Income Funds 6.0%** | **Exchange-Traded Fixed Income Funds 6.0%** |
| **Multisector 6.0%** | **Multisector 6.0%** | **Multisector 6.0%** |
| Columbia Diversified Fixed Income Allocation <br> ETF<sup>(a)</sup> <br>| &nbsp;&nbsp; 4078290 | &nbsp;&nbsp; 74265661 |
| Total Exchange-Traded Fixed Income Funds <br>(Cost $74,086,203) | Total Exchange-Traded Fixed Income Funds <br>(Cost $74,086,203) | &nbsp;&nbsp; **74265661** |

---

---

| | | |
|:---|:---|:---|
| **Fixed Income Funds 53.6%** | **Fixed Income Funds 53.6%** | **Fixed Income Funds 53.6%** |
|  | **Shares** | **Value ($)** |
| **High Yield 5.9%** | **High Yield 5.9%** | **High Yield 5.9%** |
| Columbia High Yield Bond Fund, Institutional 3 <br> Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 6668761 | &nbsp;&nbsp; 74289996 |
| **Investment Grade 47.7%** | **Investment Grade 47.7%** | **Investment Grade 47.7%** |
| Columbia Corporate Income Fund, Institutional 3 <br> Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 16163407 | &nbsp;&nbsp; 148541708 |
| Columbia Quality Income Fund, Institutional 3 <br> Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 6175344 | &nbsp;&nbsp; 112082494 |
| Columbia Total Return Bond Fund, Institutional 3 <br> Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 6059729 | &nbsp;&nbsp; 186336656 |
| Columbia U.S. Treasury Index Fund, Institutional <br> 3 Class<sup>(a)</sup> <br>| &nbsp;&nbsp; 14828923 | &nbsp;&nbsp; 148289234 |
| **Total** | **Total** | &nbsp;&nbsp; **595250092** |
| Total Fixed Income Funds <br>(Cost $650,456,095) | Total Fixed Income Funds <br>(Cost $650,456,095) | &nbsp;&nbsp; **669540088** |
| **Money Market Funds 0.3%** | **Money Market Funds 0.3%** | **Money Market Funds 0.3%** |
| Columbia Short-Term Cash Fund, 4.473%<sup>(a),(c)</sup> <br>| &nbsp;&nbsp; 3950796 | &nbsp;&nbsp; 3950006 |
| Total Money Market Funds <br>(Cost $3,949,445) | Total Money Market Funds <br>(Cost $3,949,445) | &nbsp;&nbsp; **3950006** |
| **Total Investments in Securities** <br>**(Cost: $1,144,030,842)** | **Total Investments in Securities** <br>**(Cost: $1,144,030,842)** | &nbsp;&nbsp; **1249487859** |
| **Other Assets & Liabilities, Net** |  | &nbsp;&nbsp; **(882846)**<br>|
| **Net Assets** | **Net Assets** | &nbsp;&nbsp; **1248605013** |

---

**Notes to Portfolio of Investments** 

&nbsp;&nbsp;&nbsp;&nbsp;(a) Under Section 2(a)(3) of the Investment Company Act of 1940, an affiliated company is one in which the Fund owns 5% or more of the company's outstanding voting securities, or a company which is under common ownership or control with the Fund.
 The value of the holdings and transactions in these affiliated companies during the period ended June 30, 2025 are as follows:

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Affiliated issuers** | **Beginning** <br>**of period($)**<br>| **Purchases($)** | **Sales($)** | **Net change in** <br>**unrealized** <br>**appreciation** <br>**(depreciation)($)**<br>| **End of** <br>**period($)**<br>| **Capital gain** <br>**distributions($)**<br>| **Realized gain** <br>**(loss)($)**<br>| **Dividends —** <br>**affiliated** <br>**issuers ($)**<br>| **End of** <br>**period shares**<br>|
| Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  | Columbia Contrarian Core Fund, Institutional 3 Class  |
|  | 74265906 | 99398700 | (63544868)<br>| 15370031 | 125489769 |  | 2321353 |  | 3234272 |
| Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  | Columbia Corporate Income Fund, Institutional 3 Class  |
|  | 180071090 | 49518344 | (87131381)<br>| 6083655 | 148541708 |  | (3311180)<br>| 3469869 | 16163407 |
| Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  | Columbia Diversified Fixed Income Allocation ETF  |
|  | 89144643 | 22672248 | (41659823)<br>| 4108593 | 74265661 |  | (1358716)<br>| 1505773 | 4078290 |
| Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  | Columbia High Yield Bond Fund, Institutional 3 Class  |
|  | 90169866 | 23041807 | (40228944)<br>| 1307267 | 74289996 |  | (469286)<br>| 2191898 | 6668761 |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Thermostat Fund<sup>SM</sup>, June 30, 2025 (Unaudited)

**Notes to Portfolio of Investments (continued)**

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Affiliated issuers** | **Beginning**<br> **of period($)**<br>| **Purchases($)** | **Sales($)** | **Net change in** <br> **unrealized** <br> **appreciation** <br> **(depreciation)($)**<br>| **End of** <br> **period($)**<br>| **Capital gain**<br> **distributions($)**<br>| **Realized gain**<br> **(loss)($)**<br>| **Dividends —**<br> **affiliated**<br> **issuers ($)**<br>| **End of**<br> **period shares**<br>|
| Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  | Columbia Large Cap Enhanced Core Fund, Institutional 3 Class  |
|  | 74525468 | 101172397 | (60302242)<br>| 9414773 | 124810396 | 3335563 | 1299487 | 215721 | 4496052 |
| Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  | Columbia Large Cap Growth Fund, Institutional 3 Class  |
|  | 29688679 | 41570614 | (26443928)<br>| 5633046 | 50448411 |  | 2189223 |  | 622897 |
| Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  | Columbia Large Cap Index Fund, Institutional 3 Class  |
|  | 59756842 | 88638813 | (48331019)<br>| 374765 | 100439401 | 10553819 | 2335565 | 186589 | 1853125 |
| Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  | Columbia Quality Income Fund, Institutional 3 Class  |
|  | 134970124 | 38692502 | (74598083)<br>| 13017951 | 112082494 |  | (7458298)<br>| 2271243 | 6175344 |
| Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  | Columbia Research Enhanced Core ETF  |
|  | 29495409 | 98503963 | (37941140)<br>| 10485895 | 100544127 |  | 1748867 |  | 2732920 |
| Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  | Columbia Short-Term Cash Fund, 4.473%  |
|  | 3388538 | 83755331 | (83194423)<br>| 560 | 3950006 |  | (184)<br>| 103193 | 3950796 |
| Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  | Columbia Small Cap Index Fund, Institutional 3 Class  |
|  | 28668806 | 41403621 | (70048921)<br>| (23506)<br>|  |  | (2602376)<br>|  |  |
| Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  | Columbia Total Return Bond Fund, Institutional 3 Class  |
|  | 225118342 | 64298438 | (110493650)<br>| 7413526 | 186336656 |  | (649921)<br>| 4672180 | 6059729 |
| Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  | Columbia U.S. Treasury Index Fund, Institutional 3 Class  |
|  | 179923815 | 51440034 | (88846216)<br>| 5771601 | 148289234 |  | (1911855)<br>| 2648220 | 14828923 |
| Total | 1199187528 |  |  | 78958157 | 1249487859 | 13889382 | (7867321)<br>| 17264686 |  |

---

&nbsp;&nbsp;&nbsp;&nbsp;(b) Non-income producing investment.

&nbsp;&nbsp;&nbsp;&nbsp;(c) The rate shown is the seven-day current annualized yield at June 30, 2025.

**Fair value measurements** 

The Fund categorizes its fair value measurements according to a three-level hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs by prioritizing that the most observable input be used when available. Observable inputs are those that market participants would use in pricing an investment based on market data obtained from sources independent of the reporting entity. Unobservable inputs are those that reflect the Fund's assumptions about the information market participants would use in pricing an investment. An investment's level within the fair value hierarchy is based on the lowest level of any input that is deemed significant to the asset's or liability's fair value measurement. The input levels are not necessarily an indication of the risk or liquidity associated with investments at that level. For example, certain U.S. government securities are generally high quality and liquid, however, they are reflected as Level 2 because the inputs used to determine fair value may not always be quoted prices in an active market.

Fair value inputs are summarized in the three broad levels listed below:

■

Level 1 — Valuations based on quoted prices for investments in active markets that the Fund has the ability to access at the measurement date. Valuation adjustments are not applied to Level 1 investments.

■

Level 2 — Valuations based on other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risks, etc.).

■

Level 3 — Valuations based on significant unobservable inputs (including the Fund's own assumptions and judgment in determining the fair value of investments).

Inputs that are used in determining fair value of an investment may include price information, credit data, volatility statistics, and other factors. These inputs can be either observable or unobservable. The availability of observable inputs can vary between investments, and is affected by various factors such as the type of investment, and the volume and level of activity for that investment or similar investments in the marketplace. The inputs will be considered by the Investment Manager, along with any other relevant factors in the calculation of an investment's fair value. The Fund uses prices and inputs that are current as of the measurement date, which may include periods of market dislocations. During these periods, the availability of prices and inputs may be reduced for many investments. This condition could cause an investment to be reclassified between the various levels within the hierarchy.

Investments falling into the Level 3 category, if any, are primarily supported by quoted prices from brokers and dealers participating in the market for those investments. However, these may be classified as Level 3 investments due to lack of market transparency and corroboration to support these quoted prices. Additionally, valuation models may be used as the pricing source for any remaining investments classified as Level 3. These models may rely on one or more significant unobservable inputs and/or significant assumptions by the Investment Manager. Inputs used in valuations may include, but are not limited to, financial statement analysis, capital account balances, discount rates and estimated cash flows, and comparable company data.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Thermostat Fund<sup>SM</sup>, June 30, 2025 (Unaudited)

**Fair value measurements (continued)**

The Fund's Board of Trustees (the Board) has designated the Investment Manager, through its Valuation Committee (the Committee), as valuation designee, responsible for determining the fair value of the assets of the Fund for which market quotations are not readily available using valuation procedures approved by the Board. The Committee consists of voting and non-voting members from various groups within the Investment Manager's organization, including operations and accounting, trading and investments, compliance, risk management and legal.

The Committee meets at least monthly to review and approve valuation matters, which may include a description of specific valuation determinations, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are or are not readily available, including recommendations of third party pricing vendors and a determination of appropriate pricing methodologies; events that require specific valuation determinations and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third party pricing vendors, including periodic reviews of vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions. Representatives of Columbia Management Investment Advisers, LLC report to the Board at each of its regularly scheduled meetings to discuss valuation matters and actions during the period, similar to those described earlier.

The following table is a summary of the inputs used to value the Fund's investments at June 30, 2025:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** | **Total ($)** |
| **Investments in Securities** |  |  |  |  |
| Equity Funds | 401187977 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 401187977 |
| Exchange-Traded Equity Funds | 100544127 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 100544127 |
| Exchange-Traded Fixed Income Funds | 74265661 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 74265661 |
| Fixed Income Funds | 669540088 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 669540088 |
| Money Market Funds | 3950006 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3950006 |
| Total Investments in Securities | 1249487859 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1249487859 |

---

See the Portfolio of Investments for all investment classifications not indicated in the table.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments

Columbia Acorn European Fund<sup>SM</sup>, June 30, 2025 (Unaudited)

(Percentages represent value of investments compared to net assets)

**Investments in securities**

---

| | | |
|:---|:---|:---|
| **Common Stocks 95.9%** | **Common Stocks 95.9%** | **Common Stocks 95.9%** |
| **Issuer** | **Shares** | **Value ($)** |
| **Austria 4.7%** | **Austria 4.7%** | **Austria 4.7%** |
| BAWAG Group AG<sup>(a)</sup> <br>| &nbsp;&nbsp; 5440 | &nbsp;&nbsp; 695675 |
| DO & CO AG<sup>(a)</sup> <br>| &nbsp;&nbsp; 2983 | &nbsp;&nbsp; 637258 |
| Wienerberger AG | &nbsp;&nbsp; 16481 | &nbsp;&nbsp; 615928 |
| **Total** | **Total** | &nbsp;&nbsp; **1948861** |
| **Belgium 3.4%** | **Belgium 3.4%** | **Belgium 3.4%** |
| Azelis Group NV | &nbsp;&nbsp; 34765 | &nbsp;&nbsp; 555761 |
| Elia Group SA/NV | &nbsp;&nbsp; 5292 | &nbsp;&nbsp; 611196 |
| Melexis NV | &nbsp;&nbsp; 2694 | &nbsp;&nbsp; 229636 |
| **Total** | **Total** | &nbsp;&nbsp; **1396593** |
| **Denmark 0.5%** | **Denmark 0.5%** | **Denmark 0.5%** |
| NKT A/S<sup>(a)</sup> <br>| &nbsp;&nbsp; 2442 | &nbsp;&nbsp; 198129 |
| **Finland 2.2%** | **Finland 2.2%** | **Finland 2.2%** |
| Konecranes OYJ | &nbsp;&nbsp; 8822 | &nbsp;&nbsp; 701011 |
| Valmet OYJ | &nbsp;&nbsp; 5918 | &nbsp;&nbsp; 183411 |
| **Total** | **Total** | &nbsp;&nbsp; **884422** |
| **France 11.5%** | **France 11.5%** | **France 11.5%** |
| Elis SA | &nbsp;&nbsp; 42177 | &nbsp;&nbsp; 1210121 |
| Exosens SAS | &nbsp;&nbsp; 5164 | &nbsp;&nbsp; 245408 |
| Gaztransport Et Technigaz SA | &nbsp;&nbsp; 3303 | &nbsp;&nbsp; 653410 |
| Nexans SA | &nbsp;&nbsp; 6876 | &nbsp;&nbsp; 899787 |
| SCOR SE | &nbsp;&nbsp; 6367 | &nbsp;&nbsp; 211461 |
| SPIE SA | &nbsp;&nbsp; 11576 | &nbsp;&nbsp; 650925 |
| Technip Energies NV | &nbsp;&nbsp; 10188 | &nbsp;&nbsp; 428635 |
| Virbac SA | &nbsp;&nbsp; 1115 | &nbsp;&nbsp; 419703 |
| **Total** | **Total** | &nbsp;&nbsp; **4719450** |
| **Germany 7.5%** | **Germany 7.5%** | **Germany 7.5%** |
| AlzChem Group AG | &nbsp;&nbsp; 1379 | &nbsp;&nbsp; 225775 |
| Bilfinger SE | &nbsp;&nbsp; 4420 | &nbsp;&nbsp; 425458 |
| CTS Eventim AG & Co. KGaA | &nbsp;&nbsp; 7661 | &nbsp;&nbsp; 952651 |
| flatexDEGIRO AG | &nbsp;&nbsp; 22496 | &nbsp;&nbsp; 637021 |
| IONOS Group SE<sup>(a)</sup> <br>| &nbsp;&nbsp; 4160 | &nbsp;&nbsp; 195710 |
| Renk Group AG | &nbsp;&nbsp; 8141 | &nbsp;&nbsp; 651204 |
| **Total** | **Total** | &nbsp;&nbsp; **3087819** |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| **Greece 2.9%** | **Greece 2.9%** | **Greece 2.9%** |
| Alpha Bank SA | &nbsp;&nbsp; 6490 | &nbsp;&nbsp; 22858 |
| JUMBO SA | &nbsp;&nbsp; 2867 | &nbsp;&nbsp; 98951 |
| National Bank of Greece SA | &nbsp;&nbsp; 37493 | &nbsp;&nbsp; 478064 |
| Piraeus Financial Holdings SA | &nbsp;&nbsp; 88179 | &nbsp;&nbsp; 610885 |
| **Total** | **Total** | &nbsp;&nbsp; **1210758** |
| **Ireland 4.3%** | **Ireland 4.3%** | **Ireland 4.3%** |
| Cairn Homes PLC | &nbsp;&nbsp; 267635 | &nbsp;&nbsp; 676234 |
| Glanbia PLC | &nbsp;&nbsp; 28353 | &nbsp;&nbsp; 418041 |
| Irish Continental Group PLC | &nbsp;&nbsp; 72636 | &nbsp;&nbsp; 470589 |
| Uniphar PLC | &nbsp;&nbsp; 47852 | &nbsp;&nbsp; 212073 |
| **Total** | **Total** | &nbsp;&nbsp; **1776937** |
| **Italy 4.6%** | **Italy 4.6%** | **Italy 4.6%** |
| Buzzi SpA | &nbsp;&nbsp; 13582 | &nbsp;&nbsp; 753259 |
| Carel Industries SpA | &nbsp;&nbsp; 9869 | &nbsp;&nbsp; 263071 |
| De' Longhi SpA | &nbsp;&nbsp; 12390 | &nbsp;&nbsp; 415956 |
| Intercos SpA | &nbsp;&nbsp; 13712 | &nbsp;&nbsp; 208684 |
| Reply SpA | &nbsp;&nbsp; 1490 | &nbsp;&nbsp; 257502 |
| **Total** | **Total** | &nbsp;&nbsp; **1898472** |
| **Jersey 1.2%** | **Jersey 1.2%** | **Jersey 1.2%** |
| JTC PLC | &nbsp;&nbsp; 40175 | &nbsp;&nbsp; 470617 |
| **Netherlands 2.2%** | **Netherlands 2.2%** | **Netherlands 2.2%** |
| BE Semiconductor Industries NV | &nbsp;&nbsp; 1720 | &nbsp;&nbsp; 257232 |
| CTP NV<sup>(b)</sup> <br>| &nbsp;&nbsp; 31041 | &nbsp;&nbsp; 653961 |
| **Total** | **Total** | &nbsp;&nbsp; **911193** |
| **Norway 3.0%** | **Norway 3.0%** | **Norway 3.0%** |
| Storebrand ASA | &nbsp;&nbsp; 65717 | &nbsp;&nbsp; 930742 |
| TOMRA Systems ASA | &nbsp;&nbsp; 19640 | &nbsp;&nbsp; 306552 |
| **Total** | **Total** | &nbsp;&nbsp; **1237294** |
| **Portugal 1.8%** | **Portugal 1.8%** | **Portugal 1.8%** |
| Banco Comercial Portugues SA | &nbsp;&nbsp; 953478 | &nbsp;&nbsp; 742794 |
| **Spain 3.3%** | **Spain 3.3%** | **Spain 3.3%** |
| Fluidra SA | &nbsp;&nbsp; 16909 | &nbsp;&nbsp; 423920 |
| Indra Sistemas SA | &nbsp;&nbsp; 6960 | &nbsp;&nbsp; 301969 |
| Vidrala SA | &nbsp;&nbsp; 1847 | &nbsp;&nbsp; 214623 |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn European Fund<sup>SM</sup>, June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| Viscofan SA | &nbsp;&nbsp; 5794 | &nbsp;&nbsp; 412143 |
| **Total** | **Total** | &nbsp;&nbsp; **1352655** |
| **Sweden 4.7%** | **Sweden 4.7%** | **Sweden 4.7%** |
| Avanza Bank Holding AB | &nbsp;&nbsp; 17991 | &nbsp;&nbsp; 610464 |
| Hexpol AB | &nbsp;&nbsp; 39473 | &nbsp;&nbsp; 381840 |
| Nordnet AB | &nbsp;&nbsp; 23293 | &nbsp;&nbsp; 633147 |
| Thule Group AB | &nbsp;&nbsp; 11354 | &nbsp;&nbsp; 327038 |
| **Total** | **Total** | &nbsp;&nbsp; **1952489** |
| **Switzerland 5.3%** | **Switzerland 5.3%** | **Switzerland 5.3%** |
| Accelleron Industries AG | &nbsp;&nbsp; 3204 | &nbsp;&nbsp; 225782 |
| Belimo Holding AG, Registered Shares | &nbsp;&nbsp; 269 | &nbsp;&nbsp; 274192 |
| Burckhardt Compression Holding AG | &nbsp;&nbsp; 397 | &nbsp;&nbsp; 330072 |
| Galenica AG | &nbsp;&nbsp; 1850 | &nbsp;&nbsp; 202452 |
| Inficon Holding AG, Registered Shares | &nbsp;&nbsp; 1741 | &nbsp;&nbsp; 233828 |
| Kardex Holding AG | &nbsp;&nbsp; 1296 | &nbsp;&nbsp; 450760 |
| R&S Group Holding AG<sup>(a)</sup> <br>| &nbsp;&nbsp; 7089 | &nbsp;&nbsp; 258739 |
| Tecan Group AG, Registered Shares | &nbsp;&nbsp; 954 | &nbsp;&nbsp; 195233 |
| **Total** | **Total** | &nbsp;&nbsp; **2171058** |
| **United Kingdom 32.8%** | **United Kingdom 32.8%** | **United Kingdom 32.8%** |
| 4imprint Group PLC | &nbsp;&nbsp; 4705 | &nbsp;&nbsp; 236183 |
| Allfunds Group PLC | &nbsp;&nbsp; 72532 | &nbsp;&nbsp; 557362 |
| Auction Technology Group PLC<sup>(a)</sup> <br>| &nbsp;&nbsp; 56097 | &nbsp;&nbsp; 350742 |
| Avon Technologies PLC | &nbsp;&nbsp; 3369 | &nbsp;&nbsp; 89252 |
| Beazley PLC | &nbsp;&nbsp; 47260 | &nbsp;&nbsp; 606819 |
| Bodycote PLC | &nbsp;&nbsp; 50280 | &nbsp;&nbsp; 403403 |
| Breedon Group PLC | &nbsp;&nbsp; 118231 | &nbsp;&nbsp; 626439 |
| Bridgepoint Group Ltd., Registered Shares<sup>(b)</sup> <br>| &nbsp;&nbsp; 49885 | &nbsp;&nbsp; 212819 |
| Capital & Counties Properties PLC | &nbsp;&nbsp; 302029 | &nbsp;&nbsp; 646716 |
| Chemring Group PLC | &nbsp;&nbsp; 91207 | &nbsp;&nbsp; 707762 |
| Clarkson PLC | &nbsp;&nbsp; 4602 | &nbsp;&nbsp; 206268 |
| ConvaTec Group PLC | &nbsp;&nbsp; 158738 | &nbsp;&nbsp; 628769 |
| CVS Group PLC | &nbsp;&nbsp; 34607 | &nbsp;&nbsp; 594118 |
| Diploma PLC | &nbsp;&nbsp; 7098 | &nbsp;&nbsp; 476488 |
| discoverIE Group plc | &nbsp;&nbsp; 27238 | &nbsp;&nbsp; 243771 |

---

---

| | | |
|:---|:---|:---|
| **Common Stocks (continued)** | **Common Stocks (continued)** | **Common Stocks (continued)** |
| **Issuer** | **Shares** | **Value ($)** |
| Electrocomponents PLC | &nbsp;&nbsp; 22479 | &nbsp;&nbsp; 177449 |
| Genus PLC | &nbsp;&nbsp; 16605 | &nbsp;&nbsp; 466308 |
| GlobalData PLC | &nbsp;&nbsp; 194410 | &nbsp;&nbsp; 393614 |
| Greggs PLC | &nbsp;&nbsp; 15009 | &nbsp;&nbsp; 395773 |
| Howden Joinery Group PLC | &nbsp;&nbsp; 33632 | &nbsp;&nbsp; 395496 |
| IG Group Holdings PLC | &nbsp;&nbsp; 27640 | &nbsp;&nbsp; 404187 |
| IMI PLC | &nbsp;&nbsp; 7611 | &nbsp;&nbsp; 219008 |
| Intermediate Capital Group PLC | &nbsp;&nbsp; 14855 | &nbsp;&nbsp; 394042 |
| LondonMetric Property PLC | &nbsp;&nbsp; 291823 | &nbsp;&nbsp; 814886 |
| Moonpig Group PLC | &nbsp;&nbsp; 146717 | &nbsp;&nbsp; 451688 |
| Quilter PLC<sup>(b)</sup> <br>| &nbsp;&nbsp; 401276 | &nbsp;&nbsp; 864223 |
| Rightmove PLC | &nbsp;&nbsp; 22588 | &nbsp;&nbsp; 244480 |
| Rotork PLC | &nbsp;&nbsp; 44503 | &nbsp;&nbsp; 196340 |
| Safestore Holdings PLC | &nbsp;&nbsp; 91339 | &nbsp;&nbsp; 887666 |
| SigmaRoc PLC<sup>(a)</sup> <br>| &nbsp;&nbsp; 275518 | &nbsp;&nbsp; 407158 |
| YouGov PLC | &nbsp;&nbsp; 39818 | &nbsp;&nbsp; 205270 |
| **Total** | **Total** | &nbsp;&nbsp; **13504499** |
| Total Common Stocks <br>(Cost $33,280,554) | Total Common Stocks <br>(Cost $33,280,554) | &nbsp;&nbsp; **39464040** |

---

---

| | | |
|:---|:---|:---|
| **Preferred Stocks 0.6%** | **Preferred Stocks 0.6%** | **Preferred Stocks 0.6%** |
| **Issuer** | **Shares** | **Value ($)** |
| **Germany 0.6%** | **Germany 0.6%** | **Germany 0.6%** |
| FUCHS SE | &nbsp;&nbsp; 4686 | &nbsp;&nbsp; 258984 |
| Total Preferred Stocks <br>(Cost $217,687) | Total Preferred Stocks <br>(Cost $217,687) | &nbsp;&nbsp; **258984** |

---

---

| | | |
|:---|:---|:---|
| **Money Market Funds 2.1%** | **Money Market Funds 2.1%** | **Money Market Funds 2.1%** |
|  | **Shares** | **Value ($)** |
| Columbia Short-Term Cash Fund, 4.473%<sup>(c),(d)</sup> <br>| &nbsp;&nbsp; 878881 | &nbsp;&nbsp; 878705 |
| Total Money Market Funds <br>(Cost $878,632) | Total Money Market Funds <br>(Cost $878,632) | &nbsp;&nbsp; **878705** |
| **Total Investments in Securities** <br>**(Cost $34,376,873)** | **Total Investments in Securities** <br>**(Cost $34,376,873)** | &nbsp;&nbsp; **40601729** |
| **Other Assets & Liabilities, Net** |  | &nbsp;&nbsp; **565521** |
| **Net Assets** | **Net Assets** | &nbsp;&nbsp; **$41167250** |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn European Fund<sup>SM</sup>, June 30, 2025 (Unaudited)

**Notes to Portfolio of Investments** 

&nbsp;&nbsp;&nbsp;&nbsp;(a) Non-income producing investment.

&nbsp;&nbsp;&nbsp;&nbsp;(b) Represents privately placed and other securities and instruments exempt from Securities
 and Exchange Commission registration (collectively, private placements), such as Section 4(a)(2) and Rule 144A eligible securities, which are often sold only
 to qualified institutional buyers. At June 30, 2025, the total value of these securities amounted to $1,731,003, which represents 4.20% of total net assets.

&nbsp;&nbsp;&nbsp;&nbsp;(c) The rate shown is the seven-day current annualized yield at June 30, 2025.

&nbsp;&nbsp;&nbsp;&nbsp;(d) Under Section 2(a)(3) of the Investment Company Act of 1940, an affiliated company is one in which the Fund owns 5% or more of the company's outstanding voting securities, or a company which is under common ownership or control with the Fund.
 The value of the holdings and transactions in these affiliated companies during the period ended June 30, 2025 are as follows:

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Affiliated issuers** | **Beginning** <br>**of period($)**<br>| **Purchases($)** | **Sales($)** | **Net change in** <br>**unrealized** <br>**appreciation** <br>**(depreciation)($)**<br>| **End of** <br>**period($)**<br>| **Realized gain** <br>**(loss)($)**<br>| **Dividends($)** | **End of** <br>**period shares**<br>|
| Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% | Columbia Short-Term Cash Fund, 4.473% |
|  | 361715 | &nbsp;&nbsp; 10788034 | &nbsp;&nbsp; (10271117)<br>| &nbsp;&nbsp; 73 | &nbsp;&nbsp; 878705 | &nbsp;&nbsp; (27)<br>| &nbsp;&nbsp; 10229 | &nbsp;&nbsp; 878881 |

---

**Fair value measurements** 

The Fund categorizes its fair value measurements according to a three-level hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs by prioritizing that the most observable input be used when available. Observable inputs are those that market participants would use in pricing an investment based on market data obtained from sources independent of the reporting entity. Unobservable inputs are those that reflect the Fund's assumptions about the information market participants would use in pricing an investment. An investment's level within the fair value hierarchy is based on the lowest level of any input that is deemed significant to the asset's or liability's fair value measurement. The input levels are not necessarily an indication of the risk or liquidity associated with investments at that level. For example, certain U.S. government securities are generally high quality and liquid, however, they are reflected as Level 2 because the inputs used to determine fair value may not always be quoted prices in an active market.

Fair value inputs are summarized in the three broad levels listed below:

■

Level 1 — Valuations based on quoted prices for investments in active markets that the Fund has the ability to access at the measurement date. Valuation adjustments are not applied to Level 1 investments.

■

Level 2 — Valuations based on other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risks, etc.).

■

Level 3 — Valuations based on significant unobservable inputs (including the Fund's own assumptions and judgment in determining the fair value of investments).

Inputs that are used in determining fair value of an investment may include price information, credit data, volatility statistics, and other factors. These inputs can be either observable or unobservable. The availability of observable inputs can vary between investments, and is affected by various factors such as the type of investment, and the volume and level of activity for that investment or similar investments in the marketplace. The inputs will be considered by the Investment Manager, along with any other relevant factors in the calculation of an investment's fair value. The Fund uses prices and inputs that are current as of the measurement date, which may include periods of market dislocations. During these periods, the availability of prices and inputs may be reduced for many investments. This condition could cause an investment to be reclassified between the various levels within the hierarchy.

Values of foreign equity securities actively traded in markets where there is a significant delay in the local close relative to the New York Stock Exchange may include an adjustment to reflect the impact of market movements following the close of local trading, as described in Note 2 to the financial statements – Security valuation. When such adjustments have been made, the foreign equity securities are classified as Level 2.

Investments falling into the Level 3 category, if any, are primarily supported by quoted prices from brokers and dealers participating in the market for those investments. However, these may be classified as Level 3 investments due to lack of market transparency and corroboration to support these quoted prices. Additionally, valuation models may be used as the pricing source for any remaining investments classified as Level 3. These models may rely on one or more significant unobservable inputs and/or significant assumptions by the Investment Manager. Inputs used in valuations may include, but are not limited to, financial statement analysis, capital account balances, discount rates and estimated cash flows, and comparable company data.

The Fund's Board of Trustees (the Board) has designated the Investment Manager, through its Valuation Committee (the Committee), as valuation designee, responsible for determining the fair value of the assets of the Fund for which market quotations are not readily available using valuation procedures approved by the Board. The Committee consists of voting and non-voting members from various groups within the Investment Manager's organization, including operations and accounting, trading and investments, compliance, risk management and legal.

The Committee meets at least monthly to review and approve valuation matters, which may include a description of specific valuation determinations, data regarding pricing information received from approved pricing vendors and brokers and the results of Board-approved valuation policies and procedures (the Policies). The Policies address, among other things, instances when market quotations are or are not readily available, including recommendations of third party pricing vendors and a determination of appropriate pricing methodologies; events that require specific valuation determinations and assessment of fair value techniques; securities with a potential for stale pricing, including those that are illiquid, restricted, or in default; and the effectiveness of third party pricing vendors, including periodic reviews of vendors. The Committee meets more frequently, as needed, to discuss additional valuation matters, which may include the need to review back-testing results, review time-sensitive information or approve related valuation actions. Representatives of Columbia Management Investment Advisers, LLC report to the Board at each of its regularly scheduled meetings to discuss valuation matters and actions during the period, similar to those described earlier.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Portfolio of Investments (continued)

Columbia Acorn European Fund<sup>SM</sup>, June 30, 2025 (Unaudited)

**Fair value measurements (continued)**

The following table is a summary of the inputs used to value the Fund's investments at June 30, 2025:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** | **Total ($)** |
| **Investments in Securities** |  |  |  |  |
| Common Stocks |  |  |  |  |
| Austria |  | &nbsp;&nbsp;&nbsp;&nbsp; 1948861 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1948861 |
| Belgium |  | &nbsp;&nbsp;&nbsp;&nbsp; 1396593 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1396593 |
| Denmark |  | &nbsp;&nbsp;&nbsp;&nbsp; 198129 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 198129 |
| Finland |  | &nbsp;&nbsp;&nbsp;&nbsp; 884422 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 884422 |
| France |  | &nbsp;&nbsp;&nbsp;&nbsp; 4719450 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 4719450 |
| Germany |  | &nbsp;&nbsp;&nbsp;&nbsp; 3087819 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3087819 |
| Greece | 121809 | &nbsp;&nbsp;&nbsp;&nbsp; 1088949 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1210758 |
| Ireland | 1146823 | &nbsp;&nbsp;&nbsp;&nbsp; 630114 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1776937 |
| Italy | 208684 | &nbsp;&nbsp;&nbsp;&nbsp; 1689788 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1898472 |
| Jersey |  | &nbsp;&nbsp;&nbsp;&nbsp; 470617 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 470617 |
| Netherlands |  | &nbsp;&nbsp;&nbsp;&nbsp; 911193 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 911193 |
| Norway |  | &nbsp;&nbsp;&nbsp;&nbsp; 1237294 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1237294 |
| Portugal |  | &nbsp;&nbsp;&nbsp;&nbsp; 742794 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 742794 |
| Spain |  | &nbsp;&nbsp;&nbsp;&nbsp; 1352655 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1352655 |
| Sweden |  | &nbsp;&nbsp;&nbsp;&nbsp; 1952489 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 1952489 |
| Switzerland |  | &nbsp;&nbsp;&nbsp;&nbsp; 2171058 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 2171058 |
| United Kingdom | 4071929 | &nbsp;&nbsp;&nbsp;&nbsp; 9432570 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 13504499 |
| Total Common Stocks | 5549245 | &nbsp;&nbsp;&nbsp;&nbsp; 33914795 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 39464040 |
| Preferred Stocks |  |  |  |  |
| Germany |  | &nbsp;&nbsp;&nbsp;&nbsp; 258984 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 258984 |
| Total Preferred Stocks |  | &nbsp;&nbsp;&nbsp;&nbsp; 258984 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 258984 |
| Money Market Funds | 878705 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 878705 |
| Total Investments in Securities | 6427950 | &nbsp;&nbsp;&nbsp;&nbsp; 34173779 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 40601729 |

---

See the Portfolio of Investments for all investment classifications not indicated in the table.

The Fund's assets assigned to the Level 2 input category are generally valued using the market approach, in which a security's value is determined through reference to prices and information from market transactions for similar or identical assets. These assets include certain foreign securities for which a third party statistical pricing service may be employed for purposes of fair market valuation. The model utilized by such third party statistical pricing service takes into account a security's correlation to available market data including relevant general and sector indices, currency fluctuations, depositary receipts, and futures, as applicable.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Assets and Liabilities

June 30, 2025 (Unaudited)

---

| | | | |
|:---|:---|:---|:---|
|  | **Columbia** <br>**Acorn**<sup>®</sup> <br>**Fund**<br>| **Columbia** <br>**Acorn** <br>**International**<sup>®</sup><br>| **Columbia** <br>**Acorn** <br>**International** <br>**Select**<sup>SM</sup><br>|
| **Assets** |  |  |  |
| Investments in securities, at value\* |  |  |  |
| Unaffiliated issuers (cost $2,127,258,296, $625,399,297, $160,468,969, respectively) | $2449405508 | &nbsp;&nbsp; $921374070 | &nbsp;&nbsp; $201207252 |
| Affiliated issuers (cost $69,002,265, $4,102,999, $1,674,211, respectively) | 80272877 | &nbsp;&nbsp; 4103404 | &nbsp;&nbsp; 1674308 |
| Foreign currency (cost $20, $890, $101, respectively) | 21 | &nbsp;&nbsp; 925 | &nbsp;&nbsp; 102 |
| Receivable for: |  |  |  |
| Capital shares sold | 154765 | &nbsp;&nbsp; 46217 | &nbsp;&nbsp; 1901 |
| Dividends | 194157 | &nbsp;&nbsp; 1025882 | &nbsp;&nbsp; 290093 |
| Securities lending income | 18676 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Foreign tax reclaims | 10222 | &nbsp;&nbsp; 1838129 | &nbsp;&nbsp; 896861 |
| Expense reimbursement due from Investment Manager |  | &nbsp;&nbsp; 5098 | &nbsp;&nbsp; 5792 |
| Prepaid expenses |  | &nbsp;&nbsp; 1 | &nbsp;&nbsp; — |
| Deferred compensation of board members | 182 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Other assets | 4163 | &nbsp;&nbsp; 9202 | &nbsp;&nbsp; 4163 |
| Total assets | 2530060571 | &nbsp;&nbsp; 928402928 | &nbsp;&nbsp; 204080472 |
| **Liabilities** |  |  |  |
| Due upon return of securities on loan | 61863077 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Payable for: |  |  |  |
| Capital shares redeemed | 2008896 | &nbsp;&nbsp; 716096 | &nbsp;&nbsp; 77829 |
| Foreign capital gains taxes deferred |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 280718 |
| Management services fees | 145966 | &nbsp;&nbsp; 65458 | &nbsp;&nbsp; 14535 |
| Distribution and/or service fees | 10401 | &nbsp;&nbsp; 2726 | &nbsp;&nbsp; 2441 |
| Transfer agent fees | 203453 | &nbsp;&nbsp; 74461 | &nbsp;&nbsp; 23590 |
| Compensation of chief compliance officer | 248 | &nbsp;&nbsp; 91 | &nbsp;&nbsp; 19 |
| Compensation of board members |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 794 |
| Other expenses | 17486 | &nbsp;&nbsp; 36037 | &nbsp;&nbsp; 19049 |
| Deferred compensation of board members | 4077555 | &nbsp;&nbsp; 1827999 | &nbsp;&nbsp; 140482 |
| Total liabilities | 68327082 | &nbsp;&nbsp; 2722868 | &nbsp;&nbsp; 559457 |
| **Net assets applicable to outstanding capital stock** | **$2461733489** | &nbsp;&nbsp; **$925680060** | &nbsp;&nbsp; **$203521015** |
| **Represented by** |  |  |  |
| Paid in capital | 2256986464 | &nbsp;&nbsp; 715904622 | &nbsp;&nbsp; 171450496 |
| Total distributable earnings (loss) | 204747025 | &nbsp;&nbsp; 209775438 | &nbsp;&nbsp; 32070519 |
| **Total - representing net assets applicable to outstanding capital stock** | **$2461733489** | &nbsp;&nbsp; **$925680060** | &nbsp;&nbsp; **$203521015** |
| \* Includes the value of securities on loan | 60428091 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Assets and Liabilities (continued)

June 30, 2025 (Unaudited)

---

| | | | |
|:---|:---|:---|:---|
|  | **Columbia**<br> **Acorn**<sup>®</sup><br> **Fund**<br>| **Columbia**<br> **Acorn**<br> **International**<sup>®</sup><br>| **Columbia**<br> **Acorn**<br> **International**<br> **Select**<sup>SM</sup><br>|
| **Class A** |  |  |  |
| Net assets | $483456776 | &nbsp;&nbsp; $132673452 | &nbsp;&nbsp; $118891294 |
| Shares outstanding | 58743207 | &nbsp;&nbsp; 5396507 | &nbsp;&nbsp; 4234230 |
| Net asset value per share | $8.23 | &nbsp;&nbsp; $24.59 | &nbsp;&nbsp; $28.08 |
| Maximum sales charge  | 5.75% | &nbsp;&nbsp; 5.75% | &nbsp;&nbsp; 5.75% |
| Maximum offering price per share (calculated by dividing the net asset value per share by 1.0 minus the <br> maximum sales charge for Class A shares)<br>| $8.73 | &nbsp;&nbsp; $26.09 | &nbsp;&nbsp; $29.79 |
| **Class C** |  |  |  |
| Net assets | $5545905 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— |
| Shares outstanding | 491213 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Net asset value per share | $11.29 | &nbsp;&nbsp; $— | &nbsp;&nbsp; $— |
| **Institutional Class** |  |  |  |
| Net assets | $1614973921 | &nbsp;&nbsp; $579520326 | &nbsp;&nbsp; $59098752 |
| Shares outstanding | 133979643 | &nbsp;&nbsp; 23393897 | &nbsp;&nbsp; 2059162 |
| Net asset value per share | $12.05 | &nbsp;&nbsp; $24.77 | &nbsp;&nbsp; $28.70 |
| **Institutional 2 Class** |  |  |  |
| Net assets | $26190839 | &nbsp;&nbsp; $19398435 | &nbsp;&nbsp; $3414804 |
| Shares outstanding | 1967967 | &nbsp;&nbsp; 783302 | &nbsp;&nbsp; 117581 |
| Net asset value per share | $13.31 | &nbsp;&nbsp; $24.76 | &nbsp;&nbsp; $29.04 |
| **Institutional 3 Class** |  |  |  |
| Net assets | $24667743 | &nbsp;&nbsp; $79108065 | &nbsp;&nbsp; $9151797 |
| Shares outstanding | 1819973 | &nbsp;&nbsp; 3126402 | &nbsp;&nbsp; 315107 |
| Net asset value per share | $13.55 | &nbsp;&nbsp; $25.30 | &nbsp;&nbsp; $29.04 |
| **Class S** |  |  |  |
| Net assets | $306898305 | &nbsp;&nbsp; $114979782 | &nbsp;&nbsp; $12964368 |
| Shares outstanding | 25458140 | &nbsp;&nbsp; 4641084 | &nbsp;&nbsp; 451697 |
| Net asset value per share | $12.06 | &nbsp;&nbsp; $24.77 | &nbsp;&nbsp; $28.70 |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Assets and Liabilities (continued)

June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
|  | **Columbia** <br>**Thermostat** <br>**Fund**<sup>SM</sup><br>| **Columbia** <br>**Acorn** <br>**European** <br>**Fund**<sup>SM</sup><br>|
| **Assets** |  |  |
| Investments in securities, at value |  |  |
| Unaffiliated issuers (cost $—, $33,498,241, respectively) | $— | &nbsp;&nbsp; $39723024 |
| Affiliated issuers (cost $1,144,030,842, $878,632, respectively) | 1249487859 | &nbsp;&nbsp; 878705 |
| Cash |  | &nbsp;&nbsp; 3123 |
| Receivable for: |  |  |
| Investments sold |  | &nbsp;&nbsp; 965149 |
| Capital shares sold | 450902 | &nbsp;&nbsp; 117950 |
| Dividends | 2521525 | &nbsp;&nbsp; 43465 |
| Securities lending income |  | &nbsp;&nbsp; 162 |
| Foreign tax reclaims |  | &nbsp;&nbsp; 224092 |
| Expense reimbursement due from Investment Manager |  | &nbsp;&nbsp; 1395 |
| Other assets | 4162 | &nbsp;&nbsp; 18753 |
| Total assets | 1252464448 | &nbsp;&nbsp; 41975818 |
| **Liabilities** |  |  |
| Foreign currency (cost $—, $2,321, respectively) |  | &nbsp;&nbsp; 2334 |
| Payable for: |  |  |
| Investments purchased | 2502061 | &nbsp;&nbsp; 614523 |
| Capital shares redeemed | 756503 | &nbsp;&nbsp; 130509 |
| Management services fees | 10230 | &nbsp;&nbsp; 3273 |
| Distribution and/or service fees | 15157 | &nbsp;&nbsp; 525 |
| Transfer agent fees | 120757 | &nbsp;&nbsp; 5240 |
| Compensation of chief compliance officer | 117 | &nbsp;&nbsp; 4 |
| Compensation of board members |  | &nbsp;&nbsp; 1627 |
| Other expenses | 27479 | &nbsp;&nbsp; 19742 |
| Deferred compensation of board members | 427131 | &nbsp;&nbsp; 30791 |
| Total liabilities | 3859435 | &nbsp;&nbsp; 808568 |
| **Net assets applicable to outstanding capital stock** | **$1248605013** | &nbsp;&nbsp; **$41167250** |
| **Represented by** |  |  |
| Paid in capital | 1254262030 | &nbsp;&nbsp; 30785962 |
| Total distributable earnings (loss) | (5657017)<br>| &nbsp;&nbsp; 10381288 |
| **Total - representing net assets applicable to outstanding capital stock** | **$1248605013** | &nbsp;&nbsp; **$41167250** |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Assets and Liabilities (continued)

June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
|  | **Columbia**<br> **Thermostat**<br> **Fund**<sup>SM</sup><br>| **Columbia**<br> **Acorn**<br> **European**<br> **Fund**<sup>SM</sup><br>|
| **Class A** |  |  |
| Net assets | $392341115 | &nbsp;&nbsp; $25700770 |
| Shares outstanding | 22295200 | &nbsp;&nbsp; 886999 |
| Net asset value per share | $17.60 | &nbsp;&nbsp; $28.97 |
| Maximum sales charge  | 5.75% | &nbsp;&nbsp; 5.75% |
| Maximum offering price per share (calculated by dividing the net asset value per share by 1.0 minus the maximum sales charge for <br> Class A shares)<br>| $18.67 | &nbsp;&nbsp; $30.74 |
| **Class C** |  |  |
| Net assets | $86891545 | &nbsp;&nbsp; $— |
| Shares outstanding | 4919753 | &nbsp;&nbsp; — |
| Net asset value per share | $17.66 | &nbsp;&nbsp; $— |
| **Institutional Class** |  |  |
| Net assets | $664365296 | &nbsp;&nbsp; $15466480 |
| Shares outstanding | 38490946 | &nbsp;&nbsp; 528793 |
| Net asset value per share | $17.26 | &nbsp;&nbsp; $29.25 |
| **Institutional 2 Class** |  |  |
| Net assets | $81025055 | &nbsp;&nbsp; $— |
| Shares outstanding | 4647961 | &nbsp;&nbsp; — |
| Net asset value per share | $17.43 | &nbsp;&nbsp; $— |
| **Institutional 3 Class** |  |  |
| Net assets | $11169282 | &nbsp;&nbsp; $— |
| Shares outstanding | 642030 | &nbsp;&nbsp; — |
| Net asset value per share | $17.40 | &nbsp;&nbsp; $— |
| **Class S** |  |  |
| Net assets | $12812720 | &nbsp;&nbsp; $— |
| Shares outstanding | 742311 | &nbsp;&nbsp; — |
| Net asset value per share | $17.26 | &nbsp;&nbsp; $— |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Operations

Six Months Ended June 30, 2025 (Unaudited)

---

| | | | |
|:---|:---|:---|:---|
|  | **Columbia** <br>**Acorn**<sup>®</sup> <br>**Fund**<br>| **Columbia** <br>**Acorn** <br>**International**<sup>®</sup><br>| **Columbia** <br>**Acorn** <br>**International** <br>**Select**<sup>SM</sup><br>|
| **Net investment income** |  |  |  |
| Income: |  |  |  |
| Dividends — unaffiliated issuers | $4619060 | &nbsp;&nbsp; $10919218 | &nbsp;&nbsp; $2707864 |
| Dividends — affiliated issuers | 1746724 | &nbsp;&nbsp; 135239 | &nbsp;&nbsp; 50294 |
| Income from securities lending — net | 159475 | &nbsp;&nbsp; 33739 | &nbsp;&nbsp; — |
| European Union tax reclaim | 1212619 | &nbsp;&nbsp; — | &nbsp;&nbsp; 916899 |
| Foreign taxes withheld | (8850)<br>| &nbsp;&nbsp; (935683)<br>| &nbsp;&nbsp; (220676)<br>|
| Total income | 7729028 | &nbsp;&nbsp; 10152513 | &nbsp;&nbsp; 3454381 |
| Expenses: |  |  |  |
| Management services fees | 8583098 | &nbsp;&nbsp; 3761964 | &nbsp;&nbsp; 833662 |
| Distribution and/or service fees |  |  |  |
| Class A | 603640 | &nbsp;&nbsp; 154082 | &nbsp;&nbsp; 140429 |
| Class C | 29751 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Transfer agent fees |  |  |  |
| Class A | 205584 | &nbsp;&nbsp; 70472 | &nbsp;&nbsp; 110566 |
| Class C | 2524 | &nbsp;&nbsp; — | &nbsp;&nbsp; — |
| Institutional Class | 678655 | &nbsp;&nbsp; 304610 | &nbsp;&nbsp; 54435 |
| Institutional 2 Class | 6739 | &nbsp;&nbsp; 4860 | &nbsp;&nbsp; 1012 |
| Institutional 3 Class | 757 | &nbsp;&nbsp; 2589 | &nbsp;&nbsp; 228 |
| Class S | 131412 | &nbsp;&nbsp; 62115 | &nbsp;&nbsp; 11992 |
| Administration fees | 322198 | &nbsp;&nbsp; 110533 | &nbsp;&nbsp; 23974 |
| Custodian fees | 9322 | &nbsp;&nbsp; 49871 | &nbsp;&nbsp; 10316 |
| Printing and postage fees | 44929 | &nbsp;&nbsp; 38439 | &nbsp;&nbsp; 21344 |
| Registration fees | 48123 | &nbsp;&nbsp; 40819 | &nbsp;&nbsp; 38490 |
| Accounting services fees | 14288 | &nbsp;&nbsp; 15769 | &nbsp;&nbsp; 15442 |
| Legal fees | 37121 | &nbsp;&nbsp; 13647 | &nbsp;&nbsp; 7749 |
| Line of credit interest |  | &nbsp;&nbsp; 3510 | &nbsp;&nbsp; 60 |
| Compensation of chief compliance officer | 209 | &nbsp;&nbsp; 72 | &nbsp;&nbsp; 16 |
| Compensation of board members | 33805 | &nbsp;&nbsp; 14482 | &nbsp;&nbsp; 6748 |
| Deferred compensation of board members | (474532)<br>| &nbsp;&nbsp; (211861)<br>| &nbsp;&nbsp; (9951)<br>|
| Other | 70781 | &nbsp;&nbsp; 52994 | &nbsp;&nbsp; 30307 |
| Total expenses | 10348404 | &nbsp;&nbsp; 4488967 | &nbsp;&nbsp; 1296819 |
| Fees waived or expenses reimbursed by Investment Manager and its affiliates |  | &nbsp;&nbsp; (140677)<br>| &nbsp;&nbsp; (293819)<br>|
| Fees waived by transfer agent |  |  |  |
| Institutional 2 Class |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (79)<br>|
| Institutional 3 Class |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (146)<br>|
| Total net expenses | 10348404 | &nbsp;&nbsp; 4348290 | &nbsp;&nbsp; 1002775 |
| **Net investment income (loss)** | (2619376)<br>| &nbsp;&nbsp; 5804223 | &nbsp;&nbsp; 2451606 |
| **Realized and unrealized gain (loss) — net** |  |  |  |
| Net realized gain (loss) on: |  |  |  |
| Investments — unaffiliated issuers | 71297570 | &nbsp;&nbsp; (3723570)<br>| &nbsp;&nbsp; 2055953 |
| Investments — affiliated issuers | 1877 | &nbsp;&nbsp; (2511)<br>| &nbsp;&nbsp; 685 |
| Foreign currency translations |  | &nbsp;&nbsp; 109461 | &nbsp;&nbsp; 55008 |
| Net realized gain (loss) | 71299447 | &nbsp;&nbsp; (3616620)<br>| &nbsp;&nbsp; 2111646 |
| Net change in unrealized appreciation (depreciation) on: |  |  |  |
| Investments — unaffiliated issuers | (169971524)<br>| &nbsp;&nbsp; 139614833 | &nbsp;&nbsp; 21853418 |
| Investments — affiliated issuers | (3645969)<br>| &nbsp;&nbsp; 405 | &nbsp;&nbsp; (102)<br>|
| Foreign currency translations | 1 | &nbsp;&nbsp; 202392 | &nbsp;&nbsp; 89487 |
| Foreign capital gains tax |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (9988)<br>|
| Net change in unrealized appreciation (depreciation) | (173617492)<br>| &nbsp;&nbsp; 139817630 | &nbsp;&nbsp; 21932815 |
| Net realized and unrealized gain (loss) | (102318045)<br>| &nbsp;&nbsp; 136201010 | &nbsp;&nbsp; 24044461 |
| **Net increase (decrease) in net assets resulting from operations** | **$(104937421)**<br>| &nbsp;&nbsp; **$142005233** | &nbsp;&nbsp; **$26496067** |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Operations (continued)

Six Months Ended June 30, 2025 (Unaudited)

---

| | | |
|:---|:---|:---|
|  | **Columbia** <br>**Thermostat** <br>**Fund**<sup>SM</sup><br>| **Columbia** <br>**Acorn** <br>**European** <br>**Fund**<sup>SM</sup><br>|
| **Net investment income** |  |  |
| Income: |  |  |
| Dividends — unaffiliated issuers | $— | &nbsp;&nbsp; $841672 |
| Dividends — affiliated issuers | 17264686 | &nbsp;&nbsp; 10229 |
| Income from securities lending — net |  | &nbsp;&nbsp; 1110 |
| Foreign taxes withheld |  | &nbsp;&nbsp; (83805)<br>|
| Total income | 17264686 | &nbsp;&nbsp; 769206 |
| Expenses: |  |  |
| Management services fees | 588905 | &nbsp;&nbsp; 205291 |
| Distribution and/or service fees |  |  |
| Class A | 470628 | &nbsp;&nbsp; 28876 |
| Class C | 421949 | &nbsp;&nbsp; — |
| Transfer agent fees |  |  |
| Class A | 178278 | &nbsp;&nbsp; 14530 |
| Class C | 39955 | &nbsp;&nbsp; — |
| Institutional Class | 292924 | &nbsp;&nbsp; 10401 |
| Institutional 2 Class | 20732 | &nbsp;&nbsp; — |
| Institutional 3 Class | 419 | &nbsp;&nbsp; — |
| Class S | 5860 | &nbsp;&nbsp; — |
| Administration fees | 146580 | &nbsp;&nbsp; 5105 |
| Custodian fees | 1153 | &nbsp;&nbsp; 14781 |
| Printing and postage fees | 39618 | &nbsp;&nbsp; 10759 |
| Registration fees | 56238 | &nbsp;&nbsp; 18222 |
| Accounting services fees | 4172 | &nbsp;&nbsp; 14288 |
| Legal fees | 18907 | &nbsp;&nbsp; 6206 |
| Line of credit interest | 539 | &nbsp;&nbsp; 90 |
| Compensation of chief compliance officer | 99 | &nbsp;&nbsp; 3 |
| Compensation of board members | 17638 | &nbsp;&nbsp; 5100 |
| Deferred compensation of board members | (23556)<br>| &nbsp;&nbsp; (929)<br>|
| Other | 32413 | &nbsp;&nbsp; 1865 |
| Total expenses | 2313451 | &nbsp;&nbsp; 334588 |
| Fees waived or expenses reimbursed by Investment Manager and its affiliates | (49804)<br>| &nbsp;&nbsp; (82389)<br>|
| Fees waived by transfer agent |  |  |
| Institutional 2 Class | (3567)<br>| &nbsp;&nbsp; — |
| Institutional 3 Class | (257)<br>| &nbsp;&nbsp; — |
| Total net expenses | 2259823 | &nbsp;&nbsp; 252199 |
| **Net investment income** | 15004863 | &nbsp;&nbsp; 517007 |
| **Realized and unrealized gain (loss) — net** |  |  |
| Net realized gain (loss) on: |  |  |
| Investments — unaffiliated issuers |  | &nbsp;&nbsp; 10199016 |
| Investments — affiliated issuers | (7867321)<br>| &nbsp;&nbsp; (27)<br>|
| Capital gain distributions from underlying affiliated funds | 13889382 | &nbsp;&nbsp; — |
| Foreign currency translations |  | &nbsp;&nbsp; (4038)<br>|
| Net realized gain | 6022061 | &nbsp;&nbsp; 10194951 |
| Net change in unrealized appreciation (depreciation) on: |  |  |
| Investments — unaffiliated issuers |  | &nbsp;&nbsp; (3148684)<br>|
| Investments — affiliated issuers | 78958157 | &nbsp;&nbsp; 73 |
| Foreign currency translations |  | &nbsp;&nbsp; 23621 |
| Net change in unrealized appreciation (depreciation) | 78958157 | &nbsp;&nbsp; (3124990)<br>|
| Net realized and unrealized gain | 84980218 | &nbsp;&nbsp; 7069961 |
| **Net increase in net assets resulting from operations** | **$99985081** | &nbsp;&nbsp; **$7586968** |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Changes in Net Assets

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Columbia** <br>**Acorn**<sup>®</sup> **Fund** | **Columbia** <br>**Acorn**<sup>®</sup> **Fund** | **Columbia Acorn** <br>**International**<sup>®</sup> | **Columbia Acorn** <br>**International**<sup>®</sup> |
|  | **Six Months Ended** <br>**June 30, 2025** <br>**(Unaudited)**<br>| **Year Ended** <br>**December 31, 2024**<br>| **Six Months Ended** <br>**June 30, 2025** <br>**(Unaudited)**<br>| **Year Ended** <br>**December 31, 2024**<br>|
| **Operations** |  |  |  |  |
| Net investment income (loss) | $(2619376)<br>| &nbsp;&nbsp; $(15049222)<br>| &nbsp;&nbsp; $5804223 | &nbsp;&nbsp; $10026120 |
| Net realized gain (loss) | 71299447 | &nbsp;&nbsp; 354316937 | &nbsp;&nbsp; (3616620)<br>| &nbsp;&nbsp; 84164253 |
| Net change in unrealized appreciation (depreciation) | (173617492)<br>| &nbsp;&nbsp; 33556369 | &nbsp;&nbsp; 139817630 | &nbsp;&nbsp; (139384521)<br>|
| Net increase (decrease) in net assets resulting from operations | (104937421)<br>| &nbsp;&nbsp; 372824084 | &nbsp;&nbsp; 142005233 | &nbsp;&nbsp; (45194148)<br>|
| **Distributions to shareholders** |  |  |  |  |
| Net investment income and net realized gains  |  |  |  |  |
| Class A |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (3234863)<br>| &nbsp;&nbsp; (14776573)<br>|
| Advisor Class |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (187821)<br>|
| Institutional Class |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (14046800)<br>| &nbsp;&nbsp; (70673340)<br>|
| Institutional 2 Class |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (472416)<br>| &nbsp;&nbsp; (2116606)<br>|
| Institutional 3 Class |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (1876200)<br>| &nbsp;&nbsp; (12977717)<br>|
| Class S |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (2802700)<br>| &nbsp;&nbsp; (9229839)<br>|
| Total distributions to shareholders |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (22432979)<br>| &nbsp;&nbsp; (109961896)<br>|
| Decrease in net assets from capital stock activity | (162162773)<br>| &nbsp;&nbsp; (426753331)<br>| &nbsp;&nbsp; (78195552)<br>| &nbsp;&nbsp; (118727568)<br>|
| Total increase (decrease) in net assets | (267100194)<br>| &nbsp;&nbsp; (53929247)<br>| &nbsp;&nbsp; 41376702 | &nbsp;&nbsp; (273883612)<br>|
| Net assets at beginning of period | 2728833683 | &nbsp;&nbsp; 2782762930 | &nbsp;&nbsp; 884303358 | &nbsp;&nbsp; 1158186970 |
| **Net assets at end of period** | **$2461733489** | &nbsp;&nbsp; **$2728833683** | &nbsp;&nbsp; **$925680060** | &nbsp;&nbsp; **$884303358** |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Changes in Net Assets (continued)

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Columbia Acorn** <br>**International Select**<sup>SM</sup> | **Columbia Acorn** <br>**International Select**<sup>SM</sup> | **Columbia** <br>**Thermostat Fund**<sup>SM</sup> | **Columbia** <br>**Thermostat Fund**<sup>SM</sup> |
|  | **Six Months Ended** <br>**June 30, 2025** <br>**(Unaudited)**<br>| **Year Ended** <br>**December 31, 2024**<br>| **Six Months Ended** <br>**June 30, 2025** <br>**(Unaudited)**<br>| **Year Ended** <br>**December 31, 2024**<br>|
| **Operations** |  |  |  |  |
| Net investment income | $2451606 | &nbsp;&nbsp; $2095239 | &nbsp;&nbsp; $15004863 | &nbsp;&nbsp; $37470246 |
| Net realized gain | 2111646 | &nbsp;&nbsp; 17965244 | &nbsp;&nbsp; 6022061 | &nbsp;&nbsp; 22317876 |
| Net change in unrealized appreciation (depreciation) | 21932815 | &nbsp;&nbsp; (19497864)<br>| &nbsp;&nbsp; 78958157 | &nbsp;&nbsp; 34872187 |
| Net increase in net assets resulting from operations | 26496067 | &nbsp;&nbsp; 562619 | &nbsp;&nbsp; 99985081 | &nbsp;&nbsp; 94660309 |
| **Distributions to shareholders** |  |  |  |  |
| Net investment income and net realized gains  |  |  |  |  |
| Class A | (3064221)<br>| &nbsp;&nbsp; (1124318)<br>| &nbsp;&nbsp; (1843574)<br>| &nbsp;&nbsp; (12416154)<br>|
| Advisor Class |  | &nbsp;&nbsp; (10754)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (302495)<br>|
| Class C |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (408755)<br>| &nbsp;&nbsp; (2211271)<br>|
| Institutional Class | (1623542)<br>| &nbsp;&nbsp; (826746)<br>| &nbsp;&nbsp; (3171179)<br>| &nbsp;&nbsp; (21710377)<br>|
| Institutional 2 Class | (97517)<br>| &nbsp;&nbsp; (56532)<br>| &nbsp;&nbsp; (384539)<br>| &nbsp;&nbsp; (2679962)<br>|
| Institutional 3 Class | (261308)<br>| &nbsp;&nbsp; (114637)<br>| &nbsp;&nbsp; (52124)<br>| &nbsp;&nbsp; (372731)<br>|
| Class S | (355373)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; (61254)<br>| &nbsp;&nbsp; (398576)<br>|
| Total distributions to shareholders | (5401961)<br>| &nbsp;&nbsp; (2132987)<br>| &nbsp;&nbsp; (5921425)<br>| &nbsp;&nbsp; (40091566)<br>|
| Decrease in net assets from capital stock activity | (7199882)<br>| &nbsp;&nbsp; (33869049)<br>| &nbsp;&nbsp; (44084496)<br>| &nbsp;&nbsp; (198986914)<br>|
| Total increase (decrease) in net assets | 13894224 | &nbsp;&nbsp; (35439417)<br>| &nbsp;&nbsp; 49979160 | &nbsp;&nbsp; (144418171)<br>|
| Net assets at beginning of period | 189626791 | &nbsp;&nbsp; 225066208 | &nbsp;&nbsp; 1198625853 | &nbsp;&nbsp; 1343044024 |
| **Net assets at end of period** | **$203521015** | &nbsp;&nbsp; **$189626791** | &nbsp;&nbsp; **$1248605013** | &nbsp;&nbsp; **$1198625853** |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Changes in Net Assets (continued)

---

| | | |
|:---|:---|:---|
|  | **Columbia Acorn** <br>**European Fund**<sup>SM</sup> | **Columbia Acorn** <br>**European Fund**<sup>SM</sup> |
|  | **Six Months Ended** <br>**June 30, 2025** <br>**(Unaudited)**<br>| **Year Ended** <br>**December 31, 2024**<br>|
| **Operations** |  |  |
| Net investment income | $517007 | &nbsp;&nbsp; $88737 |
| Net realized gain | 10194951 | &nbsp;&nbsp; 12835372 |
| Net change in unrealized appreciation (depreciation) | (3124990)<br>| &nbsp;&nbsp; (14829291)<br>|
| Net increase (decrease) in net assets resulting from operations | 7586968 | &nbsp;&nbsp; (1905182)<br>|
| **Distributions to shareholders** |  |  |
| Net investment income and net realized gains  |  |  |
| Class A |  | &nbsp;&nbsp; (598281)<br>|
| Advisor Class |  | &nbsp;&nbsp; (15596)<br>|
| Institutional Class |  | &nbsp;&nbsp; (488108)<br>|
| Total distributions to shareholders |  | &nbsp;&nbsp; (1101985)<br>|
| Decrease in net assets from capital stock activity | (7529187)<br>| &nbsp;&nbsp; (16527056)<br>|
| Total increase (decrease) in net assets | 57781 | &nbsp;&nbsp; (19534223)<br>|
| Net assets at beginning of period | 41109469 | &nbsp;&nbsp; 60643692 |
| **Net assets at end of period** | **$41167250** | &nbsp;&nbsp; **$41109469** |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Changes in Net Assets (continued)

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Columbia** <br>**Acorn**<sup>®</sup> **Fund** | **Columbia** <br>**Acorn**<sup>®</sup> **Fund** | **Columbia** <br>**Acorn**<sup>®</sup> **Fund** | **Columbia** <br>**Acorn**<sup>®</sup> **Fund** | **Columbia Acorn** <br>**International**<sup>®</sup> | **Columbia Acorn** <br>**International**<sup>®</sup> | **Columbia Acorn** <br>**International**<sup>®</sup> | **Columbia Acorn** <br>**International**<sup>®</sup> |
|  | **Six Months Ended** | **Six Months Ended** | **Year Ended** | **Year Ended** | **Six Months Ended** | **Six Months Ended** | **Year Ended** | **Year Ended** |
|  | **June 30, 2025 (Unaudited)** | **June 30, 2025 (Unaudited)** | **December 31, 2024**  | **December 31, 2024**  | **June 30, 2025 (Unaudited)** | **June 30, 2025 (Unaudited)** | **December 31, 2024**  | **December 31, 2024**  |
|  | **Shares** | **Dollars ($)** | **Shares** | **Dollars ($)** | **Shares** | **Dollars ($)** | **Shares** | **Dollars ($)** |
| **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** |
| Class A |  |  |  |  |  |  |  |  |
| Shares sold | 571081 | &nbsp;&nbsp; 4487505 | &nbsp;&nbsp; 1132352 | &nbsp;&nbsp; 9163800 | &nbsp;&nbsp; 80690 | &nbsp;&nbsp; 1851473 | &nbsp;&nbsp; 338163 | &nbsp;&nbsp; 8410184 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 129517 | &nbsp;&nbsp; 3098041 | &nbsp;&nbsp; 623582 | &nbsp;&nbsp; 14150032 |
| Shares redeemed | (5525452)<br>| &nbsp;&nbsp; (43832453)<br>| &nbsp;&nbsp; (13562866)<br>| &nbsp;&nbsp; (109021278)<br>| &nbsp;&nbsp; (536946)<br>| &nbsp;&nbsp; (12124420)<br>| &nbsp;&nbsp; (1361129)<br>| &nbsp;&nbsp; (33790944)<br>|
| Net decrease | (4954371)<br>| &nbsp;&nbsp; (39344948)<br>| &nbsp;&nbsp; (12430514)<br>| &nbsp;&nbsp; (99857478)<br>| &nbsp;&nbsp; (326739)<br>| &nbsp;&nbsp; (7174906)<br>| &nbsp;&nbsp; (399384)<br>| &nbsp;&nbsp; (11230728)<br>|
| Advisor Class |  |  |  |  |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 218852 | &nbsp;&nbsp; 2732848 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 22985 | &nbsp;&nbsp; 590751 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 7258 | &nbsp;&nbsp; 187630 |
| Shares redeemed |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (3279577)<br>| &nbsp;&nbsp; (46124474)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (248274)<br>| &nbsp;&nbsp; (6151410)<br>|
| Net decrease |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (3060725)<br>| &nbsp;&nbsp; (43391626)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (218031)<br>| &nbsp;&nbsp; (5373029)<br>|
| Class C |  |  |  |  |  |  |  |  |
| Shares sold | 16580 | &nbsp;&nbsp; 178163 | &nbsp;&nbsp; 46214 | &nbsp;&nbsp; 496832 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 1368 | &nbsp;&nbsp; 29826 |
| Shares redeemed | (142298)<br>| &nbsp;&nbsp; (1544156)<br>| &nbsp;&nbsp; (294421)<br>| &nbsp;&nbsp; (3234271)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (148003)<br>| &nbsp;&nbsp; (3228484)<br>|
| Net decrease | (125718)<br>| &nbsp;&nbsp; (1365993)<br>| &nbsp;&nbsp; (248207)<br>| &nbsp;&nbsp; (2737439)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (146635)<br>| &nbsp;&nbsp; (3198658)<br>|
| Institutional Class |  |  |  |  |  |  |  |  |
| Shares sold | 1124194 | &nbsp;&nbsp; 12747428 | &nbsp;&nbsp; 4779528 | &nbsp;&nbsp; 60466900 | &nbsp;&nbsp; 126671 | &nbsp;&nbsp; 2878818 | &nbsp;&nbsp; 379620 | &nbsp;&nbsp; 9275114 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 519977 | &nbsp;&nbsp; 12531446 | &nbsp;&nbsp; 2738250 | &nbsp;&nbsp; 63070993 |
| Shares redeemed | (8498805)<br>| &nbsp;&nbsp; (99006884)<br>| &nbsp;&nbsp; (56498495)<br>| &nbsp;&nbsp; (679545275)<br>| &nbsp;&nbsp; (1486814)<br>| &nbsp;&nbsp; (33631696)<br>| &nbsp;&nbsp; (11509843)<br>| &nbsp;&nbsp; (296693997)<br>|
| Net decrease | (7374611)<br>| &nbsp;&nbsp; (86259456)<br>| &nbsp;&nbsp; (51718967)<br>| &nbsp;&nbsp; (619078375)<br>| &nbsp;&nbsp; (840166)<br>| &nbsp;&nbsp; (18221432)<br>| &nbsp;&nbsp; (8391973)<br>| &nbsp;&nbsp; (224347890)<br>|
| Institutional 2 Class |  |  |  |  |  |  |  |  |
| Shares sold | 267635 | &nbsp;&nbsp; 3522824 | &nbsp;&nbsp; 350551 | &nbsp;&nbsp; 4595267 | &nbsp;&nbsp; 72276 | &nbsp;&nbsp; 1650916 | &nbsp;&nbsp; 66030 | &nbsp;&nbsp; 1649754 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 19586 | &nbsp;&nbsp; 471822 | &nbsp;&nbsp; 92289 | &nbsp;&nbsp; 2113154 |
| Shares redeemed | (283256)<br>| &nbsp;&nbsp; (3590341)<br>| &nbsp;&nbsp; (751649)<br>| &nbsp;&nbsp; (9623144)<br>| &nbsp;&nbsp; (70511)<br>| &nbsp;&nbsp; (1636002)<br>| &nbsp;&nbsp; (290130)<br>| &nbsp;&nbsp; (7229364)<br>|
| Net increase (decrease) | (15621)<br>| &nbsp;&nbsp; (67517)<br>| &nbsp;&nbsp; (401098)<br>| &nbsp;&nbsp; (5027877)<br>| &nbsp;&nbsp; 21351 | &nbsp;&nbsp; 486736 | &nbsp;&nbsp; (131811)<br>| &nbsp;&nbsp; (3466456)<br>|
| Institutional 3 Class |  |  |  |  |  |  |  |  |
| Shares sold | 198947 | &nbsp;&nbsp; 2586699 | &nbsp;&nbsp; 341360 | &nbsp;&nbsp; 4439835 | &nbsp;&nbsp; 132034 | &nbsp;&nbsp; 3008439 | &nbsp;&nbsp; 461541 | &nbsp;&nbsp; 11337102 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 75874 | &nbsp;&nbsp; 1867250 | &nbsp;&nbsp; 383395 | &nbsp;&nbsp; 8931728 |
| Shares redeemed | (481250)<br>| &nbsp;&nbsp; (6209694)<br>| &nbsp;&nbsp; (534626)<br>| &nbsp;&nbsp; (7078513)<br>| &nbsp;&nbsp; (1966221)<br>| &nbsp;&nbsp; (47374309)<br>| &nbsp;&nbsp; (971545)<br>| &nbsp;&nbsp; (24990518)<br>|
| Net decrease | (282303)<br>| &nbsp;&nbsp; (3622995)<br>| &nbsp;&nbsp; (193266)<br>| &nbsp;&nbsp; (2638678)<br>| &nbsp;&nbsp; (1758313)<br>| &nbsp;&nbsp; (42498620)<br>| &nbsp;&nbsp; (126609)<br>| &nbsp;&nbsp; (4721688)<br>|
| Class R |  |  |  |  |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 1674 | &nbsp;&nbsp; 40933 |
| Shares redeemed |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (84904)<br>| &nbsp;&nbsp; (2070566)<br>|
| Net decrease |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (83230)<br>| &nbsp;&nbsp; (2029633)<br>|
| Class S |  |  |  |  |  |  |  |  |
| Shares sold | 93776 | &nbsp;&nbsp; 1112335 | &nbsp;&nbsp; 30814407 | &nbsp;&nbsp; 380431067 | &nbsp;&nbsp; 10350 | &nbsp;&nbsp; 233751 | &nbsp;&nbsp; 5384804 | &nbsp;&nbsp; 142655849 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 116118 | &nbsp;&nbsp; 2798454 | &nbsp;&nbsp; 425476 | &nbsp;&nbsp; 9220057 |
| Shares redeemed | (2785907)<br>| &nbsp;&nbsp; (32614199)<br>| &nbsp;&nbsp; (2664136)<br>| &nbsp;&nbsp; (34452925)<br>| &nbsp;&nbsp; (611037)<br>| &nbsp;&nbsp; (13819535)<br>| &nbsp;&nbsp; (684627)<br>| &nbsp;&nbsp; (16235392)<br>|
| Net increase (decrease) | (2692131)<br>| &nbsp;&nbsp; (31501864)<br>| &nbsp;&nbsp; 28150271 | &nbsp;&nbsp; 345978142 | &nbsp;&nbsp; (484569)<br>| &nbsp;&nbsp; (10787330)<br>| &nbsp;&nbsp; 5125653 | &nbsp;&nbsp; 135640514 |
| **Total net decrease** | **(15444755)**<br>| &nbsp;&nbsp; **(162162773)**<br>| &nbsp;&nbsp; **(39902506)**<br>| &nbsp;&nbsp; **(426753331)**<br>| &nbsp;&nbsp; **(3388436)**<br>| &nbsp;&nbsp; **(78195552)**<br>| &nbsp;&nbsp; **(4372020)**<br>| &nbsp;&nbsp; **(118727568)**<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Changes in Net Assets (continued)

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Columbia Acorn** <br>**International Select**<sup>SM</sup> | **Columbia Acorn** <br>**International Select**<sup>SM</sup> | **Columbia Acorn** <br>**International Select**<sup>SM</sup> | **Columbia Acorn** <br>**International Select**<sup>SM</sup> | **Columbia** <br>**Thermostat Fund**<sup>SM</sup> | **Columbia** <br>**Thermostat Fund**<sup>SM</sup> | **Columbia** <br>**Thermostat Fund**<sup>SM</sup> | **Columbia** <br>**Thermostat Fund**<sup>SM</sup> |
|  | **Six Months Ended** | **Six Months Ended** | **Year Ended** | **Year Ended** | **Six Months Ended** | **Six Months Ended** | **Year Ended** | **Year Ended** |
|  | **June 30, 2025 (Unaudited)** | **June 30, 2025 (Unaudited)** | **December 31, 2024**  | **December 31, 2024**  | **June 30, 2025 (Unaudited)** | **June 30, 2025 (Unaudited)** | **December 31, 2024**  | **December 31, 2024**  |
|  | **Shares** | **Dollars ($)** | **Shares** | **Dollars ($)** | **Shares** | **Dollars ($)** | **Shares** | **Dollars ($)** |
| **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** |
| Class A |  |  |  |  |  |  |  |  |
| Shares sold | 40597 | &nbsp;&nbsp; 1082703 | &nbsp;&nbsp; 72601 | &nbsp;&nbsp; 1877055 | &nbsp;&nbsp; 728395 | &nbsp;&nbsp; 12113229 | &nbsp;&nbsp; 1560668 | &nbsp;&nbsp; 25017144 |
| Distributions reinvested | 102517 | &nbsp;&nbsp; 2826390 | &nbsp;&nbsp; 38497 | &nbsp;&nbsp; 1033246 | &nbsp;&nbsp; 98973 | &nbsp;&nbsp; 1705309 | &nbsp;&nbsp; 703749 | &nbsp;&nbsp; 11451576 |
| Shares redeemed | (301894)<br>| &nbsp;&nbsp; (8028190)<br>| &nbsp;&nbsp; (745084)<br>| &nbsp;&nbsp; (19426483)<br>| &nbsp;&nbsp; (2233295)<br>| &nbsp;&nbsp; (36949550)<br>| &nbsp;&nbsp; (5986998)<br>| &nbsp;&nbsp; (96073826)<br>|
| Net decrease | (158780)<br>| &nbsp;&nbsp; (4119097)<br>| &nbsp;&nbsp; (633986)<br>| &nbsp;&nbsp; (16516182)<br>| &nbsp;&nbsp; (1405927)<br>| &nbsp;&nbsp; (23131012)<br>| &nbsp;&nbsp; (3722581)<br>| &nbsp;&nbsp; (59605106)<br>|
| Advisor Class |  |  |  |  |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 8189 | &nbsp;&nbsp; 221213 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 1363908 | &nbsp;&nbsp; 21181473 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 387 | &nbsp;&nbsp; 10723 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 19097 | &nbsp;&nbsp; 301351 |
| Shares redeemed |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (44025)<br>| &nbsp;&nbsp; (1173900)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (5875625)<br>| &nbsp;&nbsp; (96946631)<br>|
| Net decrease |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (35449)<br>| &nbsp;&nbsp; (941964)<br>| &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; (4492620)<br>| &nbsp;&nbsp; (75463807)<br>|
| Class C |  |  |  |  |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp; — | &nbsp;&nbsp; 642 | &nbsp;&nbsp; 13933 | &nbsp;&nbsp; 281017 | &nbsp;&nbsp; 4686051 | &nbsp;&nbsp; 457227 | &nbsp;&nbsp; 7299907 |
| Distributions reinvested |  | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 22270 | &nbsp;&nbsp; 385272 | &nbsp;&nbsp; 126698 | &nbsp;&nbsp; 2073544 |
| Shares redeemed |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (48724)<br>| &nbsp;&nbsp; (1079132)<br>| &nbsp;&nbsp; (744460)<br>| &nbsp;&nbsp; (12402753)<br>| &nbsp;&nbsp; (2287469)<br>| &nbsp;&nbsp; (36778190)<br>|
| Net decrease |  | &nbsp;&nbsp; — | &nbsp;&nbsp; (48082)<br>| &nbsp;&nbsp; (1065199)<br>| &nbsp;&nbsp; (441173)<br>| &nbsp;&nbsp; (7331430)<br>| &nbsp;&nbsp; (1703544)<br>| &nbsp;&nbsp; (27404739)<br>|
| Institutional Class |  |  |  |  |  |  |  |  |
| Shares sold | 60902 | &nbsp;&nbsp; 1668453 | &nbsp;&nbsp; 114467 | &nbsp;&nbsp; 3045470 | &nbsp;&nbsp; 3898776 | &nbsp;&nbsp; 63649489 | &nbsp;&nbsp; 10066666 | &nbsp;&nbsp; 161650690 |
| Distributions reinvested | 48375 | &nbsp;&nbsp; 1363202 | &nbsp;&nbsp; 26520 | &nbsp;&nbsp; 726909 | &nbsp;&nbsp; 153595 | &nbsp;&nbsp; 2595756 | &nbsp;&nbsp; 1142666 | &nbsp;&nbsp; 18218419 |
| Shares redeemed | (164355)<br>| &nbsp;&nbsp; (4406554)<br>| &nbsp;&nbsp; (1089922)<br>| &nbsp;&nbsp; (29535423)<br>| &nbsp;&nbsp; (4731263)<br>| &nbsp;&nbsp; (76659993)<br>| &nbsp;&nbsp; (13641826)<br>| &nbsp;&nbsp; (215349951)<br>|
| Net decrease | (55078)<br>| &nbsp;&nbsp; (1374899)<br>| &nbsp;&nbsp; (948935)<br>| &nbsp;&nbsp; (25763044)<br>| &nbsp;&nbsp; (678892)<br>| &nbsp;&nbsp; (10414748)<br>| &nbsp;&nbsp; (2432494)<br>| &nbsp;&nbsp; (35480842)<br>|
| Institutional 2 Class |  |  |  |  |  |  |  |  |
| Shares sold | 3439 | &nbsp;&nbsp; 96384 | &nbsp;&nbsp; 10380 | &nbsp;&nbsp; 281427 | &nbsp;&nbsp; 719096 | &nbsp;&nbsp; 11910371 | &nbsp;&nbsp; 1629460 | &nbsp;&nbsp; 25850054 |
| Distributions reinvested | 3420 | &nbsp;&nbsp; 97506 | &nbsp;&nbsp; 2039 | &nbsp;&nbsp; 56528 | &nbsp;&nbsp; 22527 | &nbsp;&nbsp; 384539 | &nbsp;&nbsp; 166441 | &nbsp;&nbsp; 2679962 |
| Shares redeemed | (41311)<br>| &nbsp;&nbsp; (1138994)<br>| &nbsp;&nbsp; (80948)<br>| &nbsp;&nbsp; (2160394)<br>| &nbsp;&nbsp; (871962)<br>| &nbsp;&nbsp; (14248878)<br>| &nbsp;&nbsp; (2646019)<br>| &nbsp;&nbsp; (41946646)<br>|
| Net decrease | (34452)<br>| &nbsp;&nbsp; (945104)<br>| &nbsp;&nbsp; (68529)<br>| &nbsp;&nbsp; (1822439)<br>| &nbsp;&nbsp; (130339)<br>| &nbsp;&nbsp; (1953968)<br>| &nbsp;&nbsp; (850118)<br>| &nbsp;&nbsp; (13416630)<br>|
| Institutional 3 Class |  |  |  |  |  |  |  |  |
| Shares sold | 6345 | &nbsp;&nbsp; 172219 | &nbsp;&nbsp; 32621 | &nbsp;&nbsp; 887685 | &nbsp;&nbsp; 85164 | &nbsp;&nbsp; 1392291 | &nbsp;&nbsp; 116878 | &nbsp;&nbsp; 1868513 |
| Distributions reinvested | 9145 | &nbsp;&nbsp; 260730 | &nbsp;&nbsp; 4132 | &nbsp;&nbsp; 114544 | &nbsp;&nbsp; 3049 | &nbsp;&nbsp; 51930 | &nbsp;&nbsp; 23111 | &nbsp;&nbsp; 371235 |
| Shares redeemed | (31448)<br>| &nbsp;&nbsp; (870071)<br>| &nbsp;&nbsp; (62603)<br>| &nbsp;&nbsp; (1700783)<br>| &nbsp;&nbsp; (106831)<br>| &nbsp;&nbsp; (1735071)<br>| &nbsp;&nbsp; (195591)<br>| &nbsp;&nbsp; (3100122)<br>|
| Net decrease | (15958)<br>| &nbsp;&nbsp; (437122)<br>| &nbsp;&nbsp; (25850)<br>| &nbsp;&nbsp; (698554)<br>| &nbsp;&nbsp; (18618)<br>| &nbsp;&nbsp; (290850)<br>| &nbsp;&nbsp; (55602)<br>| &nbsp;&nbsp; (860374)<br>|
| Class S |  |  |  |  |  |  |  |  |
| Shares sold | 5031 | &nbsp;&nbsp; 138305 | &nbsp;&nbsp; 507130 | &nbsp;&nbsp; 14077388 | &nbsp;&nbsp; 523 | &nbsp;&nbsp; 8364 | &nbsp;&nbsp; 832840 | &nbsp;&nbsp; 13754131 |
| Distributions reinvested | 12611 | &nbsp;&nbsp; 355373 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; 3625 | &nbsp;&nbsp; 61254 | &nbsp;&nbsp; 24942 | &nbsp;&nbsp; 398576 |
| Shares redeemed | (30198)<br>| &nbsp;&nbsp; (817338)<br>| &nbsp;&nbsp; (42877)<br>| &nbsp;&nbsp; (1139055)<br>| &nbsp;&nbsp; (64126)<br>| &nbsp;&nbsp; (1032106)<br>| &nbsp;&nbsp; (55493)<br>| &nbsp;&nbsp; (908123)<br>|
| Net increase (decrease) | (12556)<br>| &nbsp;&nbsp; (323660)<br>| &nbsp;&nbsp; 464253 | &nbsp;&nbsp; 12938333 | &nbsp;&nbsp; (59978)<br>| &nbsp;&nbsp; (962488)<br>| &nbsp;&nbsp; 802289 | &nbsp;&nbsp; 13244584 |
| **Total net decrease** | **(276824)**<br>| &nbsp;&nbsp; **(7199882)**<br>| &nbsp;&nbsp; **(1296578)**<br>| &nbsp;&nbsp; **(33869049)**<br>| &nbsp;&nbsp; **(2734927)**<br>| &nbsp;&nbsp; **(44084496)**<br>| &nbsp;&nbsp; **(12454670)**<br>| &nbsp;&nbsp; **(198986914)**<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Statement of Changes in Net Assets (continued)

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Columbia Acorn** <br>**European Fund**<sup>SM</sup> | **Columbia Acorn** <br>**European Fund**<sup>SM</sup> | **Columbia Acorn** <br>**European Fund**<sup>SM</sup> | **Columbia Acorn** <br>**European Fund**<sup>SM</sup> |
|  | **Six Months Ended** | **Six Months Ended** | **Year Ended** | **Year Ended** |
|  | **June 30, 2025 (Unaudited)** | **June 30, 2025 (Unaudited)** | **December 31, 2024**  | **December 31, 2024**  |
|  | **Shares** | **Dollars ($)** | **Shares** | **Dollars ($)** |
| **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** | **Capital stock activity** |
| Class A |  |  |  |  |
| Shares sold | 171956 | &nbsp;&nbsp;&nbsp;&nbsp; 4405073 | &nbsp;&nbsp;&nbsp;&nbsp; 194802 | &nbsp;&nbsp;&nbsp;&nbsp; 4856694 |
| Distributions reinvested |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 23930 | &nbsp;&nbsp;&nbsp;&nbsp; 597993 |
| Shares redeemed | (251065)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (6266634)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (445772)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (11331707)<br>|
| Net decrease | (79109)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (1861561)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (227040)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (5877020)<br>|
| Advisor Class |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 25009 | &nbsp;&nbsp;&nbsp;&nbsp; 647374 |
| Distributions reinvested |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 580 | &nbsp;&nbsp;&nbsp;&nbsp; 15559 |
| Shares redeemed |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (97314)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (2474422)<br>|
| Net decrease |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (71725)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (1811489)<br>|
| Class C |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 106 | &nbsp;&nbsp;&nbsp;&nbsp; 2516 |
| Shares redeemed |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (72798)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (1709763)<br>|
| Net decrease |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (72692)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (1707247)<br>|
| Institutional Class |  |  |  |  |
| Shares sold | 36746 | &nbsp;&nbsp;&nbsp;&nbsp; 962904 | &nbsp;&nbsp;&nbsp;&nbsp; 132787 | &nbsp;&nbsp;&nbsp;&nbsp; 3317734 |
| Distributions reinvested |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 19359 | &nbsp;&nbsp;&nbsp;&nbsp; 485098 |
| Shares redeemed | (258260)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (6630530)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (325949)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (8389451)<br>|
| Net decrease | (221514)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (5667626)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (173803)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (4586619)<br>|
| Institutional 2 Class |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3862 | &nbsp;&nbsp;&nbsp;&nbsp; 100981 |
| Shares redeemed |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (105850)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (2599932)<br>|
| Net decrease |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (101988)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (2498951)<br>|
| Institutional 3 Class |  |  |  |  |
| Shares sold |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 3 | &nbsp;&nbsp;&nbsp;&nbsp; 50 |
| Shares redeemed |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (1898)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (45780)<br>|
| Net decrease |  | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (1895)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (45730)<br>|
| **Total net decrease** | **(300623)**<br>| &nbsp;&nbsp;&nbsp;&nbsp; **(7529187)**<br>| &nbsp;&nbsp;&nbsp;&nbsp; **(649143)**<br>| &nbsp;&nbsp;&nbsp;&nbsp; **(16527056)**<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights

Columbia Acorn<sup>®</sup> Fund

The following tables are intended to help you understand the Funds' financial performance. Certain information reflects financial results for a single share of a class held for the periods shown. Per share net investment income (loss) amounts are calculated based on average shares outstanding during the period. Total return assumes reinvestment of all dividends and distributions, if any. Total return does not reflect payment of sales charges, if any. Total return and portfolio turnover are not annualized for periods of less than one year. The ratios of expenses and net investment income are annualized for periods of less than one year. The portfolio turnover rate is calculated without regard to purchase and sales transactions of short-term instruments and certain derivatives, if any. If such transactions were included, a fund's portfolio turnover rate may be higher.

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income** <br>**(loss)**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | $8.55<br>| &nbsp;&nbsp; (0.02 )<sup>(c)</sup><br>| &nbsp;&nbsp; (0.30) <br>| &nbsp;&nbsp; (0.32) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024 | $7.49<br>| &nbsp;&nbsp; (0.06) <br>| 1.12<br>| 1.06<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2023 | $6.16<br>| &nbsp;&nbsp; (0.03) <br>| 1.36<br>| 1.33<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $10.01<br>| &nbsp;&nbsp; (0.04) <br>| &nbsp;&nbsp; (3.34) <br>| &nbsp;&nbsp; (3.38) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.47) <br>| &nbsp;&nbsp; (0.47) <br>|
| Year Ended 12/31/2021 | $12.69<br>| &nbsp;&nbsp; (0.10) <br>| 1.07<br>| 0.97<br>| &nbsp;&nbsp; (0.14) <br>| &nbsp;&nbsp; (3.51) <br>| &nbsp;&nbsp; (3.65) <br>|
| Year Ended 12/31/2020 | $11.71<br>| &nbsp;&nbsp; (0.06) <br>| 3.24<br>| 3.18<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (2.20) <br>| &nbsp;&nbsp; (2.20) <br>|
| **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** |
| Six Months Ended 6/30/2025 (Unaudited) | $11.77<br>| &nbsp;&nbsp; (0.06 )<sup>(c)</sup><br>| &nbsp;&nbsp; (0.42) <br>| &nbsp;&nbsp; (0.48) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024 | $10.39<br>| &nbsp;&nbsp; (0.17) <br>| 1.55<br>| 1.38<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2023 | $8.61<br>| &nbsp;&nbsp; (0.11) <br>| 1.89<br>| 1.78<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $13.72<br>| &nbsp;&nbsp; (0.13) <br>| &nbsp;&nbsp; (4.57) <br>| &nbsp;&nbsp; (4.70) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.41) <br>| &nbsp;&nbsp; (0.41) <br>|
| Year Ended 12/31/2021 | $16.14<br>| &nbsp;&nbsp; (0.26) <br>| 1.40<br>| 1.14<br>| &nbsp;&nbsp; (0.13) <br>| &nbsp;&nbsp; (3.43) <br>| &nbsp;&nbsp; (3.56) <br>|
| Year Ended 12/31/2020<sup>(g)</sup> <br>| $16.57<br>| &nbsp;&nbsp; (0.20) <br>| 4.08<br>| 3.88<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (4.31) <br>| &nbsp;&nbsp; (4.31) <br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $12.51<br>| &nbsp;&nbsp; (0.01 )<sup>(c)</sup><br>| &nbsp;&nbsp; (0.45) <br>| &nbsp;&nbsp; (0.46) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024 | $10.93<br>| &nbsp;&nbsp; (0.06) <br>| 1.64<br>| 1.58<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2023 | $8.97<br>| &nbsp;&nbsp; (0.02) <br>| 1.98<br>| 1.96<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $14.22<br>| &nbsp;&nbsp; (0.03) <br>| &nbsp;&nbsp; (4.75) <br>| &nbsp;&nbsp; (4.78) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.47) <br>| &nbsp;&nbsp; (0.47) <br>|
| Year Ended 12/31/2021 | $16.60<br>| &nbsp;&nbsp; (0.09) <br>| 1.43<br>| 1.34<br>| &nbsp;&nbsp; (0.13) <br>| &nbsp;&nbsp; (3.59) <br>| &nbsp;&nbsp; (3.72) <br>|
| Year Ended 12/31/2020 | $14.70<br>| &nbsp;&nbsp; (0.04) <br>| 4.14<br>| 4.10<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (2.20) <br>| &nbsp;&nbsp; (2.20) <br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $13.81<br>| &nbsp;&nbsp; (0.01 )<sup>(c)</sup><br>| &nbsp;&nbsp; (0.49) <br>| &nbsp;&nbsp; (0.50) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024 | $12.06<br>| &nbsp;&nbsp; (0.06) <br>| 1.81<br>| 1.75<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2023 | $9.89<br>| &nbsp;&nbsp; (0.02) <br>| 2.19<br>| 2.17<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $15.62<br>| &nbsp;&nbsp; (0.03) <br>| &nbsp;&nbsp; (5.23) <br>| &nbsp;&nbsp; (5.26) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.47) <br>| &nbsp;&nbsp; (0.47) <br>|
| Year Ended 12/31/2021 | $17.88<br>| &nbsp;&nbsp; (0.10) <br>| 1.57<br>| 1.47<br>| &nbsp;&nbsp; (0.13) <br>| &nbsp;&nbsp; (3.60) <br>| &nbsp;&nbsp; (3.73) <br>|
| Year Ended 12/31/2020 | $15.69<br>| &nbsp;&nbsp; (0.04) <br>| 4.43<br>| 4.39<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (2.20) <br>| &nbsp;&nbsp; (2.20) <br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $14.06<br>| &nbsp;&nbsp; (0.01 )<sup>(c)</sup><br>| &nbsp;&nbsp; (0.50) <br>| &nbsp;&nbsp; (0.51) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024 | $12.28<br>| &nbsp;&nbsp; (0.05) <br>| 1.83<br>| 1.78<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2023 | $10.07<br>| &nbsp;&nbsp; (0.02) <br>| 2.23<br>| 2.21<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $15.88<br>| &nbsp;&nbsp; (0.02) <br>| &nbsp;&nbsp; (5.32) <br>| &nbsp;&nbsp; (5.34) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.47) <br>| &nbsp;&nbsp; (0.47) <br>|
| Year Ended 12/31/2021 | $18.12<br>| &nbsp;&nbsp; (0.09) <br>| 1.60<br>| 1.51<br>| &nbsp;&nbsp; (0.14) <br>| &nbsp;&nbsp; (3.61) <br>| &nbsp;&nbsp; (3.75) <br>|
| Year Ended 12/31/2020 | $15.87<br>| &nbsp;&nbsp; (0.04) <br>| 4.49<br>| 4.45<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (2.20) <br>| &nbsp;&nbsp; (2.20) <br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn<sup>®</sup> Fund

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Total gross** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a)</sup> <br>| &nbsp;&nbsp;&nbsp; **Total net** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a),(b)</sup> <br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income (loss)** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $8.23<br>| &nbsp;&nbsp;&nbsp;&nbsp; (3.74%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.05%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.05%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.41% )<sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $483457<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $8.55<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.15% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.16%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.74%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $544609<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $7.49<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.59% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.15%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.46%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $570240<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $6.16<br>| &nbsp;&nbsp;&nbsp;&nbsp; (34.01%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08% <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08% <br><sup>(e),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.53%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $521243<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $10.01<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.79%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.80%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $919643<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $12.69<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.18% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.11%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.11% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.56%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $983709<br>|
| **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $11.29<br>| &nbsp;&nbsp;&nbsp;&nbsp; (4.08%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (1.17% )<sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $5546<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $11.77<br>| &nbsp;&nbsp;&nbsp;&nbsp; 13.28% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.91%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.83% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (1.49%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $7263<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $10.39<br>| &nbsp;&nbsp;&nbsp;&nbsp; 20.67% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.90%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.83% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (1.21%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $8991<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $8.61<br>| &nbsp;&nbsp;&nbsp;&nbsp; (34.48%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.83% <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.83% <br><sup>(e),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (1.29%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $9153<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $13.72<br>| &nbsp;&nbsp;&nbsp;&nbsp; 7.95%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.83%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.83% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (1.54%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $24546<br>|
|  Year Ended 12/31/2020 <br><sup>(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; $16.14<br>| &nbsp;&nbsp;&nbsp;&nbsp; 28.27% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.86% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (1.30%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $55861<br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $12.05<br>| &nbsp;&nbsp;&nbsp;&nbsp; (3.68%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.16% )<sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $1614974<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $12.51<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.46% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.91%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.49%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $1767918<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $10.93<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.85% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.90%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.21%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $2110299<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $8.97<br>| &nbsp;&nbsp;&nbsp;&nbsp; (33.78%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83% <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83% <br><sup>(e),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.28%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $1865518<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $14.22<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.99%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.55%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $3413006<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $16.60<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.51% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.86% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.30%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $3569794<br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $13.31<br>| &nbsp;&nbsp;&nbsp;&nbsp; (3.62%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.77%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.77%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.13% )<sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $26191<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $13.81<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.51% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.89%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.46%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $27386<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $12.06<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.94% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.87%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.18%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $28765<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $9.89<br>| &nbsp;&nbsp;&nbsp;&nbsp; (33.83% )<sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.81% <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80% <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.26%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $23445<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $15.62<br>| &nbsp;&nbsp;&nbsp;&nbsp; 9.09% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.52%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $52797<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $17.88<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.50% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.82%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.27%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $61000<br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $13.55<br>| &nbsp;&nbsp;&nbsp;&nbsp; (3.63%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.72%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.72%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.08% )<sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $24668<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $14.06<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.50% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.84%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.41%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $29552<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $12.28<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.95% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.76%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.17%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $28181<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $10.07<br>| &nbsp;&nbsp;&nbsp;&nbsp; (33.77%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.77% <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.77% <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.23%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $47945<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $15.88<br>| &nbsp;&nbsp;&nbsp;&nbsp; 9.16%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.46%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $78955<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $18.12<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.54% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.78%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.78%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.25%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $155338<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn<sup>®</sup> Fund

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income** <br>**(loss)**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | $12.51<br>| &nbsp;&nbsp; (0.01 )<sup>(c)</sup><br>| &nbsp;&nbsp; (0.44) <br>| &nbsp;&nbsp; (0.45) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024<sup>(h)</sup> <br>| $12.23<br>| &nbsp;&nbsp; (0.01) <br>| 0.29<br>| 0.28<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|

---

---

| | |
|:---|:---|
| **Notes to Financial Highlights**  | **Notes to Financial Highlights**  |
| (a) | In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund's reported expense ratios. |
| (b) | Total net expenses include the impact of certain fee waivers/expense reimbursements made by the Investment Manager and certain of its affiliates, if applicable.  |
| (c) | Includes income resulting from European Union tax reclaims. The effect of these amounted to: |

---

---

| | | |
|:---|:---|:---|
| **Class** | **Net Investment income per share ($)** | **Net Investment income ratio (%)** |
| **Six Months Ended 6/30/2025 (Unaudited)** |  |  |
| Class A | lessthan<br> 0.01<br>| 0.10 |
| Class C | 0.01 | 0.10 |
| Institutional Class | 0.01 | 0.10 |
| Institutional 2 Class | 0.01 | 0.10 |
| Institutional 3 Class | 0.01 | 0.10 |
| Class S | 0.01 | 0.10 |

---

&nbsp;&nbsp;&nbsp;&nbsp;(d) Had the Investment Manager and/or Transfer Agent not waived fees and/or reimbursed
 a portion of expenses, total return would have been reduced.

&nbsp;&nbsp;&nbsp;&nbsp;(e) The benefits derived from expense reductions had an impact of less than 0.01%.

&nbsp;&nbsp;&nbsp;&nbsp;(f) Ratios include Trustees' fees deferred during the current period as well as any gains or losses on the Trustees' deferred compensation balances as a result of market fluctuations. If these had been excluded, expenses would have been higher by 0.03%.

&nbsp;&nbsp;&nbsp;&nbsp;(g) Per share amounts have been adjusted on a retroactive basis to reflect a 4 to 1 reverse
 stock split completed after the close of business on September 11, 2020.

&nbsp;&nbsp;&nbsp;&nbsp;(h) Class S shares commenced operations on October 2, 2024. Per share data and total return
 reflect activity from that date.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn<sup>®</sup> Fund

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Total gross** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a)</sup> <br>| &nbsp;&nbsp;&nbsp; **Total net** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a),(b)</sup> <br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income (loss)** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $12.06<br>| &nbsp;&nbsp;&nbsp;&nbsp; (3.60%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.17% )<sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $306898<br>|
|  Year Ended 12/31/2024 <br><sup>(h)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; $12.51<br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.29% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.95%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.83%<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.41%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $352105<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights

Columbia Acorn International<sup>®</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income** <br>**(loss)**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | $21.54<br>| 0.12<br>| 3.54<br>| 3.66<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; (0.53) <br>| &nbsp;&nbsp; (0.61) <br>|
| Year Ended 12/31/2024 | $25.46<br>| 0.18 <br><sup>(d)</sup><br>| &nbsp;&nbsp; (1.41) <br>| &nbsp;&nbsp; (1.23) <br>| &nbsp;&nbsp; (0.71) <br>| &nbsp;&nbsp; (1.98) <br>| &nbsp;&nbsp; (2.69) <br>|
| Year Ended 12/31/2023 | $21.34<br>| 0.09<br>| 4.03<br>| 4.12<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $33.19<br>| 0.17 <br><sup>(g)</sup><br>| &nbsp;&nbsp; (11.35) <br>| &nbsp;&nbsp; (11.18) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.67) <br>| &nbsp;&nbsp; (0.67) <br>|
| Year Ended 12/31/2021 | $34.31<br>| 0.01<br>| 4.08<br>| 4.09<br>| &nbsp;&nbsp; (0.38) <br>| &nbsp;&nbsp; (4.83) <br>| &nbsp;&nbsp; (5.21) <br>|
| Year Ended 12/31/2020 | $34.20<br>| 0.06<br>| 4.51<br>| 4.57<br>| &nbsp;&nbsp; (0.20) <br>| &nbsp;&nbsp; (4.26) <br>| &nbsp;&nbsp; (4.46) <br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $21.68<br>| 0.15<br>| 3.55<br>| 3.70<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; (0.53) <br>| &nbsp;&nbsp; (0.61) <br>|
| Year Ended 12/31/2024 | $25.66<br>| 0.26 <br><sup>(d)</sup><br>| &nbsp;&nbsp; (1.43) <br>| &nbsp;&nbsp; (1.17) <br>| &nbsp;&nbsp; (0.83) <br>| &nbsp;&nbsp; (1.98) <br>| &nbsp;&nbsp; (2.81) <br>|
| Year Ended 12/31/2023 | $21.46<br>| 0.15<br>| 4.05<br>| 4.20<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $33.28<br>| 0.23 <br><sup>(g)</sup><br>| &nbsp;&nbsp; (11.38) <br>| &nbsp;&nbsp; (11.15) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.67) <br>| &nbsp;&nbsp; (0.67) <br>|
| Year Ended 12/31/2021 | $34.47<br>| 0.10<br>| 4.09<br>| 4.19<br>| &nbsp;&nbsp; (0.55) <br>| &nbsp;&nbsp; (4.83) <br>| &nbsp;&nbsp; (5.38) <br>|
| Year Ended 12/31/2020 | $34.25<br>| 0.14<br>| 4.54<br>| 4.68<br>| &nbsp;&nbsp; (0.20) <br>| &nbsp;&nbsp; (4.26) <br>| &nbsp;&nbsp; (4.46) <br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $21.66<br>| 0.16<br>| 3.55<br>| 3.71<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; (0.53) <br>| &nbsp;&nbsp; (0.61) <br>|
| Year Ended 12/31/2024 | $25.66<br>| 0.26 <br><sup>(d)</sup><br>| &nbsp;&nbsp; (1.42) <br>| &nbsp;&nbsp; (1.16) <br>| &nbsp;&nbsp; (0.86) <br>| &nbsp;&nbsp; (1.98) <br>| &nbsp;&nbsp; (2.84) <br>|
| Year Ended 12/31/2023 | $21.45<br>| 0.17<br>| 4.04<br>| 4.21<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $33.25<br>| 0.24 <br><sup>(g)</sup><br>| &nbsp;&nbsp; (11.37) <br>| &nbsp;&nbsp; (11.13) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.67) <br>| &nbsp;&nbsp; (0.67) <br>|
| Year Ended 12/31/2021 | $34.46<br>| 0.12<br>| 4.09<br>| 4.21<br>| &nbsp;&nbsp; (0.59) <br>| &nbsp;&nbsp; (4.83) <br>| &nbsp;&nbsp; (5.42) <br>|
| Year Ended 12/31/2020 | $34.22<br>| 0.16<br>| 4.54<br>| 4.70<br>| &nbsp;&nbsp; (0.20) <br>| &nbsp;&nbsp; (4.26) <br>| &nbsp;&nbsp; (4.46) <br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $22.12<br>| 0.17<br>| 3.62<br>| 3.79<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; (0.53) <br>| &nbsp;&nbsp; (0.61) <br>|
| Year Ended 12/31/2024 | $26.15<br>| 0.28 <br><sup>(d)</sup><br>| &nbsp;&nbsp; (1.45) <br>| &nbsp;&nbsp; (1.17) <br>| &nbsp;&nbsp; (0.88) <br>| &nbsp;&nbsp; (1.98) <br>| &nbsp;&nbsp; (2.86) <br>|
| Year Ended 12/31/2023 | $21.84<br>| 0.18<br>| 4.13<br>| 4.31<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $33.83<br>| 0.26 <br><sup>(g)</sup><br>| &nbsp;&nbsp; (11.58) <br>| &nbsp;&nbsp; (11.32) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.67) <br>| &nbsp;&nbsp; (0.67) <br>|
| Year Ended 12/31/2021 | $34.99<br>| 0.15<br>| 4.14<br>| 4.29<br>| &nbsp;&nbsp; (0.62) <br>| &nbsp;&nbsp; (4.83) <br>| &nbsp;&nbsp; (5.45) <br>|
| Year Ended 12/31/2020 | $34.67<br>| 0.19<br>| 4.59<br>| 4.78<br>| &nbsp;&nbsp; (0.20) <br>| &nbsp;&nbsp; (4.26) <br>| &nbsp;&nbsp; (4.46) <br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn International<sup>®</sup>

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income (loss)** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $24.59<br>| &nbsp;&nbsp;&nbsp;&nbsp; 17.07%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.25% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.22% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $132673<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $21.54<br>| &nbsp;&nbsp;&nbsp;&nbsp; (5.09%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.38% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.22% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.73% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 28%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $123302<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $25.46<br>| &nbsp;&nbsp;&nbsp;&nbsp; 19.31%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.37% <br><sup>(c),(f)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.24% <br><sup>(c),(e),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.41%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 46%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $155877<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $21.34<br>| &nbsp;&nbsp;&nbsp;&nbsp; (33.81%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.27% <br><sup>(c),(f),(h)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.23% <br><sup>(c),(e),(f),(h)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.71%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $151725<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $33.19<br>| &nbsp;&nbsp;&nbsp;&nbsp; 12.63%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.24% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.23% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.03%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $282125<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $34.31<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.68%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.28% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.24% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 55%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $283478<br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $24.77<br>| &nbsp;&nbsp;&nbsp;&nbsp; 17.15%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.00% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.96% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.34%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $579520<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $21.68<br>| &nbsp;&nbsp;&nbsp;&nbsp; (4.82%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.13% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.97% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.01% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 28%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $525326<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $25.66<br>| &nbsp;&nbsp;&nbsp;&nbsp; 19.57%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.12% <br><sup>(c),(f)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.99% <br><sup>(c),(e),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.66%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 46%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $837217<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $21.46<br>| &nbsp;&nbsp;&nbsp;&nbsp; (33.63%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.03% <br><sup>(c),(f),(h)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.98% <br><sup>(c),(e),(f),(h)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.96%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $906415<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $33.28<br>| &nbsp;&nbsp;&nbsp;&nbsp; 12.89%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.99% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.98% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.28%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $1727042<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $34.47<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.99%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.03% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.99% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.46%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 55%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $1760927<br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $24.76<br>| &nbsp;&nbsp;&nbsp;&nbsp; 17.21%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.94% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.90% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.42%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $19398<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $21.66<br>| &nbsp;&nbsp;&nbsp;&nbsp; (4.79%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.09% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.92% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.03% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 28%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $16507<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $25.66<br>| &nbsp;&nbsp;&nbsp;&nbsp; 19.63%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.05% <br><sup>(c),(f)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.92% <br><sup>(c),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.75%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 46%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $22937<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $21.45<br>| &nbsp;&nbsp;&nbsp;&nbsp; (33.60%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 0.97% <br><sup>(c),(f),(h)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.92% <br><sup>(c),(f),(h)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.04%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $80059<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $33.25<br>| &nbsp;&nbsp;&nbsp;&nbsp; 12.97%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.95% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.92% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.34%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $126973<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $34.46<br>| &nbsp;&nbsp;&nbsp;&nbsp; 15.06%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.97% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.92% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.53%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 55%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $129576<br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $25.30<br>| &nbsp;&nbsp;&nbsp;&nbsp; 17.21%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.88% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.85% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.46%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $79108<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $22.12<br>| &nbsp;&nbsp;&nbsp;&nbsp; (4.75%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.03% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.88% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.07% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 28%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $108049<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $26.15<br>| &nbsp;&nbsp;&nbsp;&nbsp; 19.73%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.01% <br><sup>(c),(f)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.89% <br><sup>(c),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.77%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 46%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $131038<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $21.84<br>| &nbsp;&nbsp;&nbsp;&nbsp; (33.58%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 0.92% <br><sup>(c),(f),(h)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.88% <br><sup>(c),(f),(h)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.10%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $133738<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $33.83<br>| &nbsp;&nbsp;&nbsp;&nbsp; 13.00%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.90% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.88% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.40%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $179991<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $34.99<br>| &nbsp;&nbsp;&nbsp;&nbsp; 15.10%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.93% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.88% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.60%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 55%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $277614<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn International<sup>®</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income** <br>**(loss)**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | $21.68<br>| 0.15<br>| 3.55<br>| 3.70<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; (0.53) <br>| &nbsp;&nbsp; (0.61) <br>|
| Year Ended 12/31/2024<sup>(i)</sup> <br>| $26.68<br>| 0.00 <br><sup>(d),(j)</sup><br>| &nbsp;&nbsp; (3.14) <br>| &nbsp;&nbsp; (3.14) <br>| &nbsp;&nbsp; (0.31) <br>| &nbsp;&nbsp; (1.55) <br>| &nbsp;&nbsp; (1.86) <br>|

---

---

| | |
|:---|:---|
| **Notes to Financial Highlights**  | **Notes to Financial Highlights**  |
| (a) | In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund's reported expense ratios. |
| (b) | Total net expenses include the impact of certain fee waivers/expense reimbursements made by the Investment Manager and certain of its affiliates, if applicable.  |
| (c) | Ratios include line of credit interest expense. For the periods indicated below, if line of credit interest expense had been excluded, expenses would have been lower by: |

---

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **Class** | **6/30/2025** | **12/31/2024** | **12/31/2023** | **12/31/2022** | **12/31/2021** | **12/31/2020** |
| Class A | less than 0.01% | less than 0.01% | &nbsp;&nbsp; 0.01% | less than 0.01% | &nbsp;&nbsp; —% | less than 0.01% |
| Institutional Class | less than 0.01% | less than 0.01% | &nbsp;&nbsp; 0.01% | less than 0.01% | &nbsp;&nbsp; —% | less than 0.01% |
| Institutional 2 Class | less than 0.01% | less than 0.01% | less than 0.01% | less than 0.01% | &nbsp;&nbsp; —% | less than 0.01% |
| Institutional 3 Class | less than 0.01% | less than 0.01% | &nbsp;&nbsp; 0.01% | less than 0.01% | &nbsp;&nbsp; —% | less than 0.01% |
| Class S | less than 0.01% | less than 0.01% | &nbsp;&nbsp; —% | &nbsp;&nbsp; —% | &nbsp;&nbsp; —% | &nbsp;&nbsp; —% |

---

&nbsp;&nbsp;&nbsp;&nbsp;(d) Includes income resulting from European Union tax reclaims. The effect of these amounted
 to:

---

| | | |
|:---|:---|:---|
| **Class** | **Net Investment income per share ($)** | **Net Investment income ratio (%)** |
| **Year Ended 12/31/2024** |  |  |
| Class A | 0.04 | 0.17 |
| Institutional Class | 0.04 | 0.17 |
| Institutional 2 Class | 0.04 | 0.17 |
| Institutional 3 Class | 0.04 | 0.17 |
| Class S | 0.01 | 0.17 |

---

&nbsp;&nbsp;&nbsp;&nbsp;(e) The benefits derived from expense reductions had an impact of less than 0.01%.

&nbsp;&nbsp;&nbsp;&nbsp;(f) Ratios include interest on collateral expense which is less than 0.01%.

&nbsp;&nbsp;&nbsp;&nbsp;(g) Net investment income per share includes European Union tax reclaims. The effect of
 these reclaims amounted to $0.02 per share.

&nbsp;&nbsp;&nbsp;&nbsp;(h) Ratios include Trustees' fees deferred during the current period as well as any gains or losses on the Trustees' deferred compensation balances as a result of market fluctuations. If these had been excluded, expenses would have been higher by 0.03%.

&nbsp;&nbsp;&nbsp;&nbsp;(i) Class S shares commenced operations on October 2, 2024. Per share data and total return
 reflect activity from that date.

&nbsp;&nbsp;&nbsp;&nbsp;(j) Rounds to zero.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn International<sup>®</sup>

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income (loss)** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $24.77<br>| &nbsp;&nbsp;&nbsp;&nbsp; 17.15%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.00% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.97% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.32%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $114980<br>|
|  Year Ended 12/31/2024 <br><sup>(i)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; $21.68<br>| &nbsp;&nbsp;&nbsp;&nbsp; (11.76%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.20% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.97% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.08% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 28%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $111119<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights

Columbia Acorn International Select<sup>SM</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income** <br>**(loss)**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | $25.18<br>| 0.32 <br><sup>(c)</sup><br>| 3.32<br>| 3.64<br>| &nbsp;&nbsp; (0.74) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.74) <br>|
| Year Ended 12/31/2024 | $25.48<br>| 0.23<br>| &nbsp;&nbsp; (0.29) <br>| &nbsp;&nbsp; (0.06) <br>| &nbsp;&nbsp; (0.24) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.24) <br>|
| Year Ended 12/31/2023 | $21.57<br>| 0.07<br>| 3.84<br>| 3.91<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $35.43<br>| 0.12 <br><sup>(f)</sup><br>| &nbsp;&nbsp; (13.06) <br>| &nbsp;&nbsp; (12.94) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.92) <br>| &nbsp;&nbsp; (0.92) <br>|
| Year Ended 12/31/2021 | $33.67<br>| &nbsp;&nbsp; (0.05) <br>| 3.50<br>| 3.45<br>| &nbsp;&nbsp; (0.28) <br>| &nbsp;&nbsp; (1.41) <br>| &nbsp;&nbsp; (1.69) <br>|
| Year Ended 12/31/2020 | $28.58<br>| &nbsp;&nbsp; (0.03) <br>| 5.21<br>| 5.18<br>| &nbsp;&nbsp; (0.09) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.09) <br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $25.75<br>| 0.36 <br><sup>(c)</sup><br>| 3.39<br>| 3.75<br>| &nbsp;&nbsp; (0.80) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.80) <br>|
| Year Ended 12/31/2024 | $26.04<br>| 0.31<br>| &nbsp;&nbsp; (0.30) <br>| 0.01<br>| &nbsp;&nbsp; (0.30) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.30) <br>|
| Year Ended 12/31/2023 | $21.99<br>| 0.13<br>| 3.92<br>| 4.05<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $36.01<br>| 0.18 <br><sup>(f)</sup><br>| &nbsp;&nbsp; (13.28) <br>| &nbsp;&nbsp; (13.10) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.92) <br>| &nbsp;&nbsp; (0.92) <br>|
| Year Ended 12/31/2021 | $34.25<br>| 0.04<br>| 3.56<br>| 3.60<br>| &nbsp;&nbsp; (0.43) <br>| &nbsp;&nbsp; (1.41) <br>| &nbsp;&nbsp; (1.84) <br>|
| Year Ended 12/31/2020 | $29.00<br>| 0.03<br>| 5.31<br>| 5.34<br>| &nbsp;&nbsp; (0.09) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.09) <br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $26.07<br>| 0.37 <br><sup>(c)</sup><br>| 3.44<br>| 3.81<br>| &nbsp;&nbsp; (0.84) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.84) <br>|
| Year Ended 12/31/2024 | $26.34<br>| 0.34<br>| &nbsp;&nbsp; (0.28) <br>| 0.06<br>| &nbsp;&nbsp; (0.33) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.33) <br>|
| Year Ended 12/31/2023 | $22.22<br>| 0.15<br>| 3.97<br>| 4.12<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $36.33<br>| 0.20 <br><sup>(f)</sup><br>| &nbsp;&nbsp; (13.39) <br>| &nbsp;&nbsp; (13.19) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.92) <br>| &nbsp;&nbsp; (0.92) <br>|
| Year Ended 12/31/2021 | $34.57<br>| 0.06<br>| 3.60<br>| 3.66<br>| &nbsp;&nbsp; (0.49) <br>| &nbsp;&nbsp; (1.41) <br>| &nbsp;&nbsp; (1.90) <br>|
| Year Ended 12/31/2020 | $29.24<br>| 0.08<br>| 5.34<br>| 5.42<br>| &nbsp;&nbsp; (0.09) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.09) <br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $26.07<br>| 0.39 <br><sup>(c)</sup><br>| 3.43<br>| 3.82<br>| &nbsp;&nbsp; (0.85) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.85) <br>|
| Year Ended 12/31/2024 | $26.35<br>| 0.35<br>| &nbsp;&nbsp; (0.29) <br>| 0.06<br>| &nbsp;&nbsp; (0.34) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.34) <br>|
| Year Ended 12/31/2023 | $22.21<br>| 0.17<br>| 3.97<br>| 4.14<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2022 | $36.31<br>| 0.21 <br><sup>(f)</sup><br>| &nbsp;&nbsp; (13.39) <br>| &nbsp;&nbsp; (13.18) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.92) <br>| &nbsp;&nbsp; (0.92) <br>|
| Year Ended 12/31/2021 | $34.56<br>| 0.09<br>| 3.59<br>| 3.68<br>| &nbsp;&nbsp; (0.52) <br>| &nbsp;&nbsp; (1.41) <br>| &nbsp;&nbsp; (1.93) <br>|
| Year Ended 12/31/2020 | $29.22<br>| 0.07<br>| 5.36<br>| 5.43<br>| &nbsp;&nbsp; (0.09) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.09) <br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn International Select<sup>SM</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Total gross** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a)</sup> <br>| &nbsp;&nbsp;&nbsp; **Total net** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a),(b)</sup> <br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income (loss)** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $28.08<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.50%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.47% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.16% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.44% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $118891<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $25.18<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.30%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.55% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.23% <br><sup>(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.86%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 69%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $110629<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $25.48<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.13%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.55% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.23% <br><sup>(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.30%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $128076<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $21.57<br>| &nbsp;&nbsp;&nbsp;&nbsp; (36.80%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.50% <br><sup>(d),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.24% <br><sup>(d),(e),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.48%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $124963<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $35.43<br>| &nbsp;&nbsp;&nbsp;&nbsp; 10.49%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.44% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.23% <br><sup>(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.15%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $235103<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $33.67<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.48%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.26% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.10%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 68%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $230519<br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $28.70<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.63%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.22% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.91% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.69% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $59099<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $25.75<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.04%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.29% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.98% <br><sup>(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.14%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 69%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $54447<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $26.04<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.42%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.30% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.98% <br><sup>(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.55%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $79765<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $21.99<br>| &nbsp;&nbsp;&nbsp;&nbsp; (36.65%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.25% <br><sup>(d),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.99% <br><sup>(d),(e),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.73%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $79829<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $36.01<br>| &nbsp;&nbsp;&nbsp;&nbsp; 10.79%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.19% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.98% <br><sup>(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.10%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $159876<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $34.25<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.50%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.23%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.02% <br><sup>(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.12%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 68%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $155133<br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $29.04<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.67%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.08% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.77% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.74% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $3415<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $26.07<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.14%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.16% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.84% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.25%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 69%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $3963<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $26.34<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.54%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.16% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.86% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $5810<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $22.22<br>| &nbsp;&nbsp;&nbsp;&nbsp; (36.57%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.11% <br><sup>(d),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.89% <br><sup>(d),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.78%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $9225<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $36.33<br>| &nbsp;&nbsp;&nbsp;&nbsp; 10.87%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.10% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.89% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.17%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $51805<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $34.57<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.63%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.15%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.93%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 68%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $77420<br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $29.04<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.72%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.02% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.71% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.89% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $9152<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $26.07<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.14%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.11% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.79% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.31%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 69%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $8631<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $26.35<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.64%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.11% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.81% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.70%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 43%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $9404<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $22.21<br>| &nbsp;&nbsp;&nbsp;&nbsp; (36.56%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.06% <br><sup>(d),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.84% <br><sup>(d),(g)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.81%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $11188<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $36.31<br>| &nbsp;&nbsp;&nbsp;&nbsp; 10.93%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.05% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.84% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.24%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 27%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $28694<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $34.56<br>| &nbsp;&nbsp;&nbsp;&nbsp; 18.67%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.09%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.89%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.24%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 68%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $27064<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn International Select<sup>SM</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income** <br>**(loss)**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | $25.75<br>| 0.36 <br><sup>(c)</sup><br>| 3.39<br>| 3.75<br>| &nbsp;&nbsp; (0.80) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.80) <br>|
| Year Ended 12/31/2024<sup>(h)</sup> <br>| $27.97<br>| 0.03<br>| &nbsp;&nbsp; (2.25) <br>| &nbsp;&nbsp; (2.22) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|

---

---

| | |
|:---|:---|
| **Notes to Financial Highlights**  | **Notes to Financial Highlights**  |
| (a) | In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund's reported expense ratios. |
| (b) | Total net expenses include the impact of certain fee waivers/expense reimbursements made by the Investment Manager and certain of its affiliates, if applicable.  |
| (c) | Includes income resulting from European Union tax reclaims. The effect of these amounted to: |

---

---

| | | |
|:---|:---|:---|
| **Class** | **Net Investment income per share ($)** | **Net Investment income ratio (%)** |
| **Six Months Ended 6/30/2025 (Unaudited)** |  |  |
| Class A | 0.13 | 0.95 |
| Institutional Class | 0.13 | 0.95 |
| Institutional 2 Class | 0.13 | 0.95 |
| Institutional 3 Class | 0.13 | 0.95 |
| Class S | 0.13 | 0.95 |

---

&nbsp;&nbsp;&nbsp;&nbsp;(d) Ratios include line of credit interest expense which is less than 0.01%.

&nbsp;&nbsp;&nbsp;&nbsp;(e) The benefits derived from expense reductions had an impact of less than 0.01%.

&nbsp;&nbsp;&nbsp;&nbsp;(f) Net investment income per share includes European Union tax reclaims. The effect of
 these reclaims amounted to $0.02 per share.

&nbsp;&nbsp;&nbsp;&nbsp;(g) Ratios include Trustees' fees deferred during the current period as well as any gains or losses on the Trustees' deferred compensation balances as a result of market fluctuations. If these had been excluded, expenses would have been higher by 0.02%.

&nbsp;&nbsp;&nbsp;&nbsp;(h) Class S shares commenced operations on October 2, 2024. Per share data and total return
 reflect activity from that date.

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn International Select<sup>SM</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Total gross** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a)</sup> <br>| &nbsp;&nbsp;&nbsp; **Total net** <br>**expense** <br>**ratio to** <br>**average** <br>**net assets**<sup>(a),(b)</sup> <br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income (loss)** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $28.70<br>| &nbsp;&nbsp;&nbsp;&nbsp; 14.63%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.22% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.91% <br><sup>(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.69% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 9%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $12964<br>|
|  Year Ended 12/31/2024 <br><sup>(h)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; $25.75<br>| &nbsp;&nbsp;&nbsp;&nbsp; (7.94%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.38%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.98%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.47%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 69%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $11956<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights

Columbia Thermostat Fund<sup>SM</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | $16.28<br>| 0.20<br>| 1.20<br>| 1.40<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.08) <br>|
| Year Ended 12/31/2024 | $15.61<br>| 0.46<br>| 0.74<br>| 1.20<br>| &nbsp;&nbsp; (0.53) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.53) <br>|
| Year Ended 12/31/2023 | $14.36<br>| 0.39<br>| 1.24<br>| 1.63<br>| &nbsp;&nbsp; (0.38) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.38) <br>|
| Year Ended 12/31/2022 | $17.01<br>| 0.26<br>| &nbsp;&nbsp; (2.49) <br>| &nbsp;&nbsp; (2.23) <br>| &nbsp;&nbsp; (0.28) <br>| &nbsp;&nbsp; (0.14) <br>| &nbsp;&nbsp; (0.42) <br>|
| Year Ended 12/31/2021 | $18.31<br>| 0.24<br>| 0.89<br>| 1.13<br>| &nbsp;&nbsp; (0.26) <br>| &nbsp;&nbsp; (2.17) <br>| &nbsp;&nbsp; (2.43) <br>|
| Year Ended 12/31/2020 | $15.12<br>| 0.26<br>| 4.13<br>| 4.39<br>| &nbsp;&nbsp; (0.27) <br>| &nbsp;&nbsp; (0.93) <br>| &nbsp;&nbsp; (1.20) <br>|
| **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** |
| Six Months Ended 6/30/2025 (Unaudited) | $16.40<br>| 0.14<br>| 1.20<br>| 1.34<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.08) <br>|
| Year Ended 12/31/2024 | $15.73<br>| 0.34<br>| 0.74<br>| 1.08<br>| &nbsp;&nbsp; (0.41) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.41) <br>|
| Year Ended 12/31/2023 | $14.48<br>| 0.27<br>| 1.25<br>| 1.52<br>| &nbsp;&nbsp; (0.27) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.27) <br>|
| Year Ended 12/31/2022 | $17.14<br>| 0.14<br>| &nbsp;&nbsp; (2.49) <br>| &nbsp;&nbsp; (2.35) <br>| &nbsp;&nbsp; (0.17) <br>| &nbsp;&nbsp; (0.14) <br>| &nbsp;&nbsp; (0.31) <br>|
| Year Ended 12/31/2021 | $18.43<br>| 0.09<br>| 0.90<br>| 0.99<br>| &nbsp;&nbsp; (0.11) <br>| &nbsp;&nbsp; (2.17) <br>| &nbsp;&nbsp; (2.28) <br>|
| Year Ended 12/31/2020 | $15.23<br>| 0.12<br>| 4.16<br>| 4.28<br>| &nbsp;&nbsp; (0.15) <br>| &nbsp;&nbsp; (0.93) <br>| &nbsp;&nbsp; (1.08) <br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $15.95<br>| 0.22<br>| 1.17<br>| 1.39<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.08) <br>|
| Year Ended 12/31/2024 | $15.30<br>| 0.50<br>| 0.72<br>| 1.22<br>| &nbsp;&nbsp; (0.57) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.57) <br>|
| Year Ended 12/31/2023 | $14.08<br>| 0.42<br>| 1.22<br>| 1.64<br>| &nbsp;&nbsp; (0.42) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.42) <br>|
| Year Ended 12/31/2022 | $16.69<br>| 0.29<br>| &nbsp;&nbsp; (2.44) <br>| &nbsp;&nbsp; (2.15) <br>| &nbsp;&nbsp; (0.32) <br>| &nbsp;&nbsp; (0.14) <br>| &nbsp;&nbsp; (0.46) <br>|
| Year Ended 12/31/2021 | $18.01<br>| 0.28<br>| 0.87<br>| 1.15<br>| &nbsp;&nbsp; (0.30) <br>| &nbsp;&nbsp; (2.17) <br>| &nbsp;&nbsp; (2.47) <br>|
| Year Ended 12/31/2020 | $14.88<br>| 0.31<br>| 4.07<br>| 4.38<br>| &nbsp;&nbsp; (0.32) <br>| &nbsp;&nbsp; (0.93) <br>| &nbsp;&nbsp; (1.25) <br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $16.10<br>| 0.22<br>| 1.19<br>| 1.41<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.08) <br>|
| Year Ended 12/31/2024 | $15.44<br>| 0.50<br>| 0.73<br>| 1.23<br>| &nbsp;&nbsp; (0.57) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.57) <br>|
| Year Ended 12/31/2023 | $14.21<br>| 0.43<br>| 1.22<br>| 1.65<br>| &nbsp;&nbsp; (0.42) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.42) <br>|
| Year Ended 12/31/2022 | $16.84<br>| 0.29<br>| &nbsp;&nbsp; (2.45) <br>| &nbsp;&nbsp; (2.16) <br>| &nbsp;&nbsp; (0.33) <br>| &nbsp;&nbsp; (0.14) <br>| &nbsp;&nbsp; (0.47) <br>|
| Year Ended 12/31/2021 | $18.14<br>| 0.29<br>| 0.89<br>| 1.18<br>| &nbsp;&nbsp; (0.31) <br>| &nbsp;&nbsp; (2.17) <br>| &nbsp;&nbsp; (2.48) <br>|
| Year Ended 12/31/2020 | $14.99<br>| 0.31<br>| 4.09<br>| 4.40<br>| &nbsp;&nbsp; (0.32) <br>| &nbsp;&nbsp; (0.93) <br>| &nbsp;&nbsp; (1.25) <br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $16.06<br>| 0.23<br>| 1.19<br>| 1.42<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.08) <br>|
| Year Ended 12/31/2024 | $15.41<br>| 0.51<br>| 0.72<br>| 1.23<br>| &nbsp;&nbsp; (0.58) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.58) <br>|
| Year Ended 12/31/2023 | $14.18<br>| 0.44<br>| 1.22<br>| 1.66<br>| &nbsp;&nbsp; (0.43) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.43) <br>|
| Year Ended 12/31/2022 | $16.80<br>| 0.31<br>| &nbsp;&nbsp; (2.45) <br>| &nbsp;&nbsp; (2.14) <br>| &nbsp;&nbsp; (0.34) <br>| &nbsp;&nbsp; (0.14) <br>| &nbsp;&nbsp; (0.48) <br>|
| Year Ended 12/31/2021 | $18.11<br>| 0.36<br>| 0.82<br>| 1.18<br>| &nbsp;&nbsp; (0.32) <br>| &nbsp;&nbsp; (2.17) <br>| &nbsp;&nbsp; (2.49) <br>|
| Year Ended 12/31/2020 | $14.96<br>| 0.33<br>| 4.08<br>| 4.41<br>| &nbsp;&nbsp; (0.33) <br>| &nbsp;&nbsp; (0.93) <br>| &nbsp;&nbsp; (1.26) <br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Thermostat Fund<sup>SM</sup>

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $17.60<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.63%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.49% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.45%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 60%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $392341<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $16.28<br>| &nbsp;&nbsp;&nbsp;&nbsp; 7.68%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.56% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.50% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.83%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 114%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $385771<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $15.61<br>| &nbsp;&nbsp;&nbsp;&nbsp; 11.38%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.57% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.49% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.59%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 148%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $428092<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $14.36<br>| &nbsp;&nbsp;&nbsp;&nbsp; (13.14%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 0.54% <br><sup>(c),(e)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.50% <br><sup>(c),(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.70%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 88%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $450566<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $17.01<br>| &nbsp;&nbsp;&nbsp;&nbsp; 6.16%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.54% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.50% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.26%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 49%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $624373<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $18.31<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.27%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.56% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.50% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.53%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 97%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $505238<br>|
| **Class C** | **Class C** | **Class C** | **Class C** | **Class C** | **Class C** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $17.66<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.20%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.24% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.70%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 60%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $86892<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $16.40<br>| &nbsp;&nbsp;&nbsp;&nbsp; 6.86%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.31% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.25% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.07%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 114%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $87900<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $15.73<br>| &nbsp;&nbsp;&nbsp;&nbsp; 10.52%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.32% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.24% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.82%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 148%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $111123<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $14.48<br>| &nbsp;&nbsp;&nbsp;&nbsp; (13.75%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.29% <br><sup>(c),(e)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.25% <br><sup>(c),(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.93%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 88%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $126802<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $17.14<br>| &nbsp;&nbsp;&nbsp;&nbsp; 5.40%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.29% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.25% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.48%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 49%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $189990<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $18.43<br>| &nbsp;&nbsp;&nbsp;&nbsp; 28.28%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.31% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.25% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.72%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 97%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $208937<br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $17.26<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.74%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.24% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.69%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 60%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $664365<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $15.95<br>| &nbsp;&nbsp;&nbsp;&nbsp; 7.97%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.31% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.25% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 3.12%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 114%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $624613<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $15.30<br>| &nbsp;&nbsp;&nbsp;&nbsp; 11.66%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.32% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.24% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.85%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 148%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $636587<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $14.08<br>| &nbsp;&nbsp;&nbsp;&nbsp; (12.92%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 0.29% <br><sup>(c),(e)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.25% <br><sup>(c),(d),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.93%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 88%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $600671<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $16.69<br>| &nbsp;&nbsp;&nbsp;&nbsp; 6.42%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.29% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.25% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.52%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 49%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $902841<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $18.01<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.63%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.31% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.25% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.80%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 97%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $729119<br>|
| **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** | **Institutional 2 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $17.43<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.78%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.20% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.19% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.74%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 60%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $81025<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $16.10<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.01%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.27% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.20% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 3.11%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 114%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $76935<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $15.44<br>| &nbsp;&nbsp;&nbsp;&nbsp; 11.67%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.28% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.20% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.88%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 148%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $86925<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $14.21<br>| &nbsp;&nbsp;&nbsp;&nbsp; (12.88%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 0.25% <br><sup>(c),(e)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.20% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.94%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 88%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $90290<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $16.84<br>| &nbsp;&nbsp;&nbsp;&nbsp; 6.53%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.25% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.20% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.53%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 49%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $169246<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $18.14<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.59%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.27% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.21% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.82%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 97%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $129197<br>|
| **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** | **Institutional 3 Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $17.40<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.87%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.16% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.14% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.79%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 60%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $11169<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $16.06<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.00%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.23% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.16% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 3.18%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 114%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $10613<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $15.41<br>| &nbsp;&nbsp;&nbsp;&nbsp; 11.73%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.24% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.16% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.96%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 148%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $11038<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $14.18<br>| &nbsp;&nbsp;&nbsp;&nbsp; (12.82%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 0.21% <br><sup>(c),(e)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.16% <br><sup>(c),(e)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.04%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 88%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $10184<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $16.80<br>| &nbsp;&nbsp;&nbsp;&nbsp; 6.52%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.21% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.17% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.94%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 49%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $15581<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $18.11<br>| &nbsp;&nbsp;&nbsp;&nbsp; 29.69%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.24% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.17% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.89%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 97%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $2862<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Thermostat Fund<sup>SM</sup>

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Distributions** <br>**from net** <br>**realized** <br>**gains**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | $15.95<br>| 0.22<br>| 1.17<br>| 1.39<br>| &nbsp;&nbsp; (0.08) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.08) <br>|
| Year Ended 12/31/2024<sup>(f)</sup> <br>| $16.61<br>| 0.17<br>| &nbsp;&nbsp; (0.33 )<sup>(g)</sup><br>| &nbsp;&nbsp; (0.16) <br>| &nbsp;&nbsp; (0.50) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; (0.50) <br>|

---

---

| | |
|:---|:---|
| **Notes to Financial Highlights**  | **Notes to Financial Highlights**  |
| (a) | In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund's reported expense ratios. |
| (b) | Total net expenses include the impact of certain fee waivers/expense reimbursements made by the Investment Manager and certain of its affiliates, if applicable.  |
| (c) | Ratios include line of credit interest expense which is less than 0.01%.  |
| (d) | The benefits derived from expense reductions had an impact of less than 0.01%. |
| (e) | Ratios include Trustees' fees deferred during the current period as well as any gains or losses on the Trustees' deferred compensation balances as a result of market fluctuations. If these had been excluded, expenses would have been higher by 0.01%.  |
| (f) | Class S shares commenced operations on October 2, 2024. Per share data and total return reflect activity from that date. |
| (g) | Calculation of the net gain (loss) per share (both realized and unrealized) does not correlate to the aggregate realized and unrealized gain (loss) presented in the Statement of Operations due to timing of Fund shares sold and redeemed in relation to fluctuations in the market value of the portfolio. For a new share class, the difference may be due to the timing of the commencement of operations for the share class. |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Thermostat Fund<sup>SM</sup>

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class S** | **Class S** | **Class S** | **Class S** | **Class S** | **Class S** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $17.26<br>| &nbsp;&nbsp;&nbsp;&nbsp; 8.74%<br>&nbsp;&nbsp;&nbsp;&nbsp; 0.24% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.70%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 60%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $12813<br>|
|  Year Ended 12/31/2024 <br><sup>(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; $15.95<br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.95%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 0.34% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 0.25% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 4.44%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 114%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $12794<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights

Columbia Acorn European Fund<sup>SM</sup>

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Net asset value,** <br>**beginning of** <br>**period**<br>| **Net** <br>**investment** <br>**income** <br>**(loss)**<br>| **Net** <br>**realized** <br>**and** <br>**unrealized** <br>**gain (loss)**<br>| **Total from** <br>**investment** <br>**operations**<br>| **Distributions** <br>**from net** <br>**investment** <br>**income**<br>| **Total** <br>**distributions to** <br>**shareholders**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | $23.87<br>| 0.33<br>| 4.77<br>| 5.10<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024 | $25.55<br>| 0.02<br>| &nbsp;&nbsp; (1.12) <br>| &nbsp;&nbsp; (1.10) <br>| &nbsp;&nbsp; (0.58) <br>| &nbsp;&nbsp; (0.58) <br>|
| Year Ended 12/31/2023 | $20.61<br>| 0.06<br>| 5.04<br>| 5.10<br>| &nbsp;&nbsp; (0.16) <br>| &nbsp;&nbsp; (0.16) <br>|
| Year Ended 12/31/2022 | $33.33<br>| 0.06 <br><sup>(e)</sup><br>| &nbsp;&nbsp; (12.78) <br>| &nbsp;&nbsp; (12.72) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2021 | $27.49<br>| &nbsp;&nbsp; (0.14) <br>| 6.04<br>| 5.90<br>| &nbsp;&nbsp; (0.06) <br>| &nbsp;&nbsp; (0.06) <br>|
| Year Ended 12/31/2020 | $22.52<br>| &nbsp;&nbsp; (0.12) <br>| 5.22<br>| 5.10<br>| &nbsp;&nbsp; (0.13) <br>| &nbsp;&nbsp; (0.13) <br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | $24.06<br>| 0.34<br>| 4.85<br>| 5.19<br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2024 | $25.76<br>| 0.08<br>| &nbsp;&nbsp; (1.14) <br>| &nbsp;&nbsp; (1.06) <br>| &nbsp;&nbsp; (0.64) <br>| &nbsp;&nbsp; (0.64) <br>|
| Year Ended 12/31/2023 | $20.77<br>| 0.11<br>| 5.10<br>| 5.21<br>| &nbsp;&nbsp; (0.22) <br>| &nbsp;&nbsp; (0.22) <br>|
| Year Ended 12/31/2022 | $33.51<br>| 0.11 <br><sup>(e)</sup><br>| &nbsp;&nbsp; (12.85) <br>| &nbsp;&nbsp; (12.74) <br>| &nbsp;&nbsp; —<br>| &nbsp;&nbsp; —<br>|
| Year Ended 12/31/2021 | $27.64<br>| &nbsp;&nbsp; (0.06) <br>| 6.06<br>| 6.00<br>| &nbsp;&nbsp; (0.13) <br>| &nbsp;&nbsp; (0.13) <br>|
| Year Ended 12/31/2020 | $22.59<br>| &nbsp;&nbsp; (0.06) <br>| 5.24<br>| 5.18<br>| &nbsp;&nbsp; (0.13) <br>| &nbsp;&nbsp; (0.13) <br>|

---

---

| | |
|:---|:---|
| **Notes to Financial Highlights**  | **Notes to Financial Highlights**  |
| (a) | In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund's reported expense ratios. |
| (b) | Total net expenses include the impact of certain fee waivers/expense reimbursements made by the Investment Manager and certain of its affiliates, if applicable.  |
| (c) | Ratios include line of credit interest expense which is less than 0.01%.  |
| (d) | The benefits derived from expense reductions had an impact of less than 0.01%. |
| (e) | Net investment income per share includes special dividends. The effect of these dividends amounted to $0.01 per share. |
| (f) | Ratios include Trustees' fees deferred during the current period as well as any gains or losses on the Trustees' deferred compensation balances as a result of market fluctuations. If these had been excluded, expenses would have been higher by 0.01%.  |

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Financial Highlights (continued)

Columbia Acorn European Fund<sup>SM</sup>

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | &nbsp;&nbsp;&nbsp; **Net** <br>**asset** <br>**value,** <br>**end of** <br>**period**<br>| &nbsp;&nbsp;&nbsp; **Total** <br>**return**<br>| &nbsp;&nbsp;&nbsp; **Net investment** <br>**income (loss)** <br>**ratio to** <br>**average** <br>**net assets**<br>| &nbsp;&nbsp;&nbsp; **Portfolio** <br>**turnover**<br>| &nbsp;&nbsp;&nbsp; **Net** <br>**assets,** <br>**end of** <br>**period** <br>**(000's)**<br>|
| **Class A** | **Class A** | **Class A** | **Class A** | **Class A** | **Class A** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $28.97<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.37%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.79% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.37% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.58%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 53%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $25701<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $23.87<br>| &nbsp;&nbsp;&nbsp;&nbsp; (4.39%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.97% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.45% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.08%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 47%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $23057<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $25.55<br>| &nbsp;&nbsp;&nbsp;&nbsp; 24.76%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.92% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.45% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.24%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 23%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $30487<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $20.61<br>| &nbsp;&nbsp;&nbsp;&nbsp; (38.16%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.80% <br><sup>(c),(f)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.45% <br><sup>(c),(d),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.25%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 31%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $28892<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $33.33<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.47%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.63% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.44% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.45%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $66374<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $27.49<br>| &nbsp;&nbsp;&nbsp;&nbsp; 22.80%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.86% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.45% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.54%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 45%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $42059<br>|
| **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** | **Institutional Class** |
| Six Months Ended 6/30/2025 (Unaudited) | &nbsp;&nbsp;&nbsp;&nbsp; $29.25<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.57%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.55% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.13% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.65%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 53%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $15466<br>|
| Year Ended 12/31/2024 | &nbsp;&nbsp;&nbsp;&nbsp; $24.06<br>| &nbsp;&nbsp;&nbsp;&nbsp; (4.18%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.72% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.20% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.32%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 47%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $18053<br>|
| Year Ended 12/31/2023 | &nbsp;&nbsp;&nbsp;&nbsp; $25.76<br>| &nbsp;&nbsp;&nbsp;&nbsp; 25.09%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.67% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.20% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.47%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 23%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $23802<br>|
| Year Ended 12/31/2022 | &nbsp;&nbsp;&nbsp;&nbsp; $20.77<br>| &nbsp;&nbsp;&nbsp;&nbsp; (38.02%) <br>&nbsp;&nbsp;&nbsp;&nbsp; 1.54% <br><sup>(c),(f)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.20% <br><sup>(c),(d),(f)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.46%<br>| &nbsp;&nbsp;&nbsp;&nbsp; 31%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $38307<br>|
| Year Ended 12/31/2021 | &nbsp;&nbsp;&nbsp;&nbsp; $33.51<br>| &nbsp;&nbsp;&nbsp;&nbsp; 21.76%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.38% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.19% <br><sup>(c),(d)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.21%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 21%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $111462<br>|
| Year Ended 12/31/2020 | &nbsp;&nbsp;&nbsp;&nbsp; $27.64<br>| &nbsp;&nbsp;&nbsp;&nbsp; 23.08%<br>&nbsp;&nbsp;&nbsp;&nbsp; 1.61% <br><sup>(c)</sup><br>&nbsp;&nbsp;&nbsp;&nbsp; 1.20% <br><sup>(c)</sup><br>| &nbsp;&nbsp;&nbsp;&nbsp; (0.29%) <br>| &nbsp;&nbsp;&nbsp;&nbsp; 45%<br>| &nbsp;&nbsp;&nbsp;&nbsp; $55171<br>|

---

The accompanying Notes to Financial Statements are an integral part of this statement.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements

June 30, 2025 (Unaudited)

Note 1. Organization

Columbia Acorn<sup>®</sup> Fund, Columbia Acorn International<sup>®</sup>, Columbia Acorn International Select<sup>SM</sup>, Columbia Thermostat Fund<sup>SM</sup> and Columbia Acorn European Fund<sup>SM</sup> (each a Fund and collectively, the Funds) are each a series of Columbia Acorn Trust (the Trust). The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust. Each Fund is a diversified fund.

Columbia Thermostat Fund<sup>SM</sup> is a "fund of funds", investing significantly in affiliated funds managed by Columbia Management Investment Advisers, LLC (the Investment Manager or Columbia Management), a wholly-owned subsidiary of Ameriprise Financial, Inc. (Ameriprise Financial), or its affiliates (Underlying Funds). Columbia Thermostat Fund<sup>SM</sup> is exposed to the same risks as the Underlying Funds in direct proportion to the allocation of its assets among the Underlying Funds. For information on the investment strategies, operations and risks of the Underlying Funds, please refer to the Fund's current prospectus as well as the prospectuses and shareholder reports of the Underlying Funds, which are available from the Securities and Exchange Commission website at www.sec.gov or on the Underlying Funds' website at columbiathreadneedleus.com/investor.

**Fund shares**

The Trust may issue an unlimited number of shares (without par value). The Funds currently offer the share classes listed in the Statement of Assets and Liabilities. Although all share classes generally have identical voting, dividend and liquidation rights, each share class votes separately when required by the Trust's organizational documents or by law. Each share class has its own expense and sales charge structure. Different share classes may have different minimum initial investment amounts and pay different net investment income distribution amounts to the extent the expenses of distributing such share classes vary. Distributions to shareholders in a liquidation event will be proportional to the net asset value of each share class.

As described in each Fund's prospectus, Class A and Class C shares are available to the general public for investment. Class C shares automatically convert to Class A shares of the same Fund after 8 years. Institutional Class, Institutional 2 Class, Institutional 3 Class and Class S shares are available for purchase through authorized investment professionals to omnibus retirement plans and to certain other investors as also described in each Fund's prospectus.

Note 2. Summary of significant accounting policies

**Basis of preparation** 

Each Fund is an investment company that applies the accounting and reporting guidance in the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946, *Financial Services - Investment Companies (ASC 946).* The financial statements are prepared in accordance with U.S. generally accepted accounting principles (GAAP), which requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates.

The following is a summary of significant accounting policies followed by the Funds in the preparation of their financial statements.

**Segment reporting**

The intent of ASU 2023-07, Segment Reporting is to enable investors to better understand an entity's overall performance and to assess its potential future cash flows through improved segment disclosures. Prior to July 7, 2025, the chief operating decision maker (CODM) was Columbia Wanger Asset Management, LLC (CWAM), a wholly-owned subsidiary of Columbia Management. Effective July 7, 2025, Columbia Management is the CODM. The CODM, through its Investment Oversight Committee and Global Executive Group, is responsible for assessing performance and making decisions about resource allocation. The CODM has determined that the Funds have a single operating segment because the CODM monitors the operating results of the Funds as a whole and the Funds' long-term strategic asset allocation is pre-determined

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

in accordance with the terms of each Fund's prospectus, based on a defined investment strategy which is executed by the Funds' portfolio managers as a team. The financial information provided to and reviewed by the CODM is consistent with that presented within the Funds' financial statements.

**Security valuation**

Equity securities listed on an exchange are valued at the closing price or last trade price on their primary exchange at the close of business of the New York Stock Exchange. Securities with a closing price not readily available or not listed on any exchange are valued at the mean between the closing bid and ask prices. Listed preferred stocks convertible into common stocks are valued using an evaluated price from a pricing service.

Foreign equity securities are valued based on the closing price or last trade price on their primary exchange at the close of business of the New York Stock Exchange. If any foreign equity security closing prices are not readily available, the securities are valued at the mean of the latest quoted bid and ask prices on such exchanges or markets. Foreign currency exchange rates are determined at the scheduled closing time of the New York Stock Exchange. Many securities markets and exchanges outside the U.S. close prior to the close of the New York Stock Exchange; therefore, the closing prices for securities in such markets or on such exchanges may not fully reflect events that occur after such close but before the close of the New York Stock Exchange. In those situations, foreign securities will be fair valued pursuant to a policy approved by the Board of Trustees. Under the policy, the Fund may utilize a third-party pricing service to determine these fair values. The third-party pricing service takes into account multiple factors, including relevant general and sector indices, currency fluctuations, depositary receipts, and futures, as applicable, to determine a good faith estimate that reasonably reflects the current market conditions as of the close of the New York Stock Exchange. The fair value of a security is likely to be different from the quoted or published price, if available.

Investments in open-end investment companies (other than exchange-traded funds (ETFs)), are valued at the latest net asset value reported by those companies as of the valuation time.

Investments in the Underlying Funds (other than exchange-traded funds (ETFs)), are valued at the latest net asset value reported by those companies as of the valuation time.

Investments for which market quotations are not readily available, or that have quotations which management believes are not reflective of market value or reliable, are valued at fair value as determined in good faith under procedures approved by the Board of Trustees. If a security or class of securities (such as foreign securities) is valued at fair value, such value is likely to be different from the quoted or published price for the security, if available.

The determination of fair value often requires significant judgment. To determine fair value, management may use assumptions including but not limited to future cash flows and estimated risk premiums. Multiple inputs from various sources may be used to determine fair value.

GAAP requires disclosure regarding the inputs and valuation techniques used to measure fair value and any changes in valuation inputs or techniques. In addition, investments shall be disclosed by major category. This information is disclosed following the Funds' Portfolio of Investments.

**Foreign currency transactions and translations** 

The values of all assets and liabilities denominated in foreign currencies are generally translated into U.S. dollars at exchange rates determined at the close of regular trading on the New York Stock Exchange. Net realized and unrealized gains (losses) on foreign currency transactions and translations include gains (losses) arising from the fluctuation in exchange rates between trade and settlement dates on securities transactions, gains (losses) arising from the disposition of foreign currency and currency gains (losses) between the accrual and payment dates on dividends, interest income and foreign withholding taxes.

For financial statement purposes, the Funds do not distinguish that portion of gains (losses) on investments which is due to changes in foreign exchange rates from that which is due to changes in market prices of the investments. Such fluctuations are included with the net realized and unrealized gains (losses) on investments in the Statement of Operations.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

**Security transactions**

Security transactions are accounted for on the trade date. Cost is determined and gains (losses) are based upon the specific identification method for both financial statement and federal income tax purposes.

**Income recognition**

Corporate actions and dividend income are generally recorded net of any non-reclaimable tax withholdings, on the ex-dividend date or upon receipt of an ex-dividend notification in the case of certain foreign securities.

The Funds may receive distributions from holdings in exchange-traded funds (ETFs), limited partnerships (LPs), other regulated investment companies (RICs), and real estate investment trusts (REITs), which report information as to the character of their distributions annually. These distributions are allocated to dividend income, capital gain and return of capital based on actual information reported. To the extent actual information has not yet been reported by the REITs, estimates for return of capital may be made by the Funds' management. Return of capital is recorded as a reduction of the cost basis of securities held. If the Funds no longer own the applicable securities, return of capital is recorded as a realized gain. Management's estimates are subsequently adjusted when the actual character of the distributions is disclosed by the REITs, which could result in a proportionate change in return of capital to shareholders. No estimates are made for ETFs and RICs.

Awards from class action litigation are recorded as a reduction of cost basis if the Fund still owns the applicable securities on the payment date. If the Fund no longer owns the applicable securities on the payment date, the proceeds are recorded as realized gains.

Income and capital gain distributions from the Underlying Funds, if any, are recorded on the ex-dividend date.

**Securities lending**

Each Fund, except Columbia Thermostat Fund<sup>SM</sup>, may lend securities up to one-third of the value of its total assets to certain approved brokers, dealers, banks and or other institutional borrowers of securities that the Funds' securities lending agent has determined are credit worthy under guidelines established by the Board of Trustees, to earn additional income. The Funds retain the benefits of owning the securities, including the economic equivalent of dividends or interest generated by the security. The Funds also receive a fee for the loan. The Funds have the ability to recall the loans at any time and could do so in order to vote proxies or to sell the loaned securities. Each loan is collateralized by cash that exceeds the value of the securities on loan. The market value of the loaned securities is determined daily at the close of business of a Fund and any additional required collateral is delivered to the Fund on the next business day. The Funds have elected to invest the cash collateral in the Dreyfus Government Cash Management Fund, a third-party institutional government money market fund in accordance with investment guidelines contained in the securities lending agreement and approved by the Board of Trustees. The income earned from the securities lending program is paid to each Fund, net of any fees remitted to Goldman Sachs Agency Lending, the Funds' lending agent, and net of any borrower rebates. The Investment Manager does not retain any fees earned by the lending program. Generally, in the event of borrower default, a Fund has the right to use the collateral to offset any losses incurred. In the event a Fund is delayed or prevented from exercising its right to dispose of the collateral, there may be a potential loss to the Fund. Some of these losses may be indemnified by the lending agent. The Funds bear the risk of loss with respect to the investment of collateral. The net securities lending income earned as of June 30, 2025 by each Fund is included in the Statement of Operations.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

**Offsetting of assets and liabilities** 

The following table presents the Fund's gross and net amount of assets and liabilities available for offset under netting arrangements and under a securities lending agreement as well as any related collateral received or pledged by the Funds as of June 30, 2025:

---

| | |
|:---|:---|
|  | **Columbia** <br>**Acorn**<sup>®</sup> **Fund**<br>|
|  | **Goldman** <br>**Sachs ($)**<br>|
| **Liabilities** |  |
| Collateral on Securities Loaned | 61863077 |
| Total Liabilities | 61863077 |
| **Total Financial and Derivative Net Assets** | **(61863077)**<br>|
| Financial Instruments | 60428091 |
| **Net Amount** <sup>(a)</sup> <br>| **(1434986)**<br>|

---

&nbsp;&nbsp;&nbsp;&nbsp;(a) Represents the net amount due from/(to) counterparties in the event of default.

**Securities lending transactions** 

The following table indicates the total amount of securities loaned by type, reconciled to gross liability payable upon return of the securities loaned by the Funds as of June 30, 2025:

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Overnight and** <br>**continuous**<br>| **Up to** <br>**30 days**<br>| **30-90** <br>**days**<br>| **Greater than** <br>**90 days**<br>| **Total** |
| **Columbia Acorn**<sup>®</sup> **Fund** |  |  |  |  |  |
| Securities lending transactions  |  |  |  |  |  |
| Equity securities  | $60428091 | &nbsp;&nbsp; $—<br>| &nbsp;&nbsp; $—<br>| &nbsp;&nbsp; $—<br>| &nbsp;&nbsp; $60428091 |
| Gross amount of recognized liabilities for securities lending (collateral received)  |  |  |  |  | &nbsp;&nbsp; 61863077 |
| Amounts due to counterparty in the event of default |  |  |  |  | &nbsp;&nbsp; $1434986 |

---

**Expenses**

General expenses of the Trust are allocated to the Funds and other funds of the Trust based upon relative net assets or other expense allocation methodologies determined by the nature of the expense. Expenses directly attributable to a Fund are charged to that Fund. Expenses directly attributable to a specific class of shares are charged to that share class.

**Determination of class net asset value** 

All income, expenses (other than class-specific expenses which are charged directly to that share class, as shown in the Statement of Operations) and realized and unrealized gains (losses) are allocated to each class of a Fund on a daily basis, based on the relative net assets of each class, for purposes of determining the net asset value of each class.

**Federal income tax status**

For federal income tax purposes, each Fund is treated as a separate entity. The Funds intend to qualify each year as separate regulated investment companies under Subchapter M of the Internal Revenue Code, as amended, and will distribute substantially all of their investment company taxable income and net capital gain, if any, for their tax year, and as such will not be subject to federal income taxes. In addition, the Funds intend to distribute in each calendar year substantially all of their ordinary income, capital gain net income and certain other amounts, if any, such that the Funds should not be subject to federal excise tax. Therefore, no federal income or excise tax provisions are recorded.

**Foreign taxes**

The Funds may be subject to foreign taxes on income, gains on investments or currency repatriation, a portion of which may be recoverable. The Fund will accrue such taxes and recoveries, as applicable, based upon its current interpretation of tax rules and regulations that exist in the markets in which it invests.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

Realized gains in certain countries may be subject to foreign taxes at the Fund level, based on statutory rates. The Fund accrues for such foreign taxes on realized and unrealized gains at the appropriate rate for each jurisdiction, as applicable. The amount, if any, is disclosed as a liability in the Statement of Assets and Liabilities.

The Fund may file withholding tax reclaims in certain European Union countries to recover a portion of foreign taxes previously withheld on dividends earned, which may be reclaimable based upon certain provisions in the Treaty on the Functioning of the European Union (EU) and subsequent rulings by the European Court of Justice. The Fund may record a reclaim receivable when the amount is known, the Fund has received notice of a pending refund, and there are no significant uncertainties on collectability. Income received from EU reclaims is included in the Statement of Operations.

**Distributions to shareholders**

Distributions from net investment income, if any, are declared and paid semi-annually. Net realized capital gains, if any, are distributed at least annually. Income distributions and capital gain distributions are determined in accordance with federal income tax regulations, which may differ from GAAP.

**Guarantees and indemnifications** 

Under the Trust's organizational documents and, in some cases, by contract, its officers and trustees are indemnified against certain liabilities arising out of the performance of their duties to the Trust or its funds. In addition, certain of the Funds' contracts with their service providers contain general indemnification clauses. The Funds' maximum exposure under these arrangements is unknown since the amount of any future claims that may be made against the Funds cannot be determined, and the Funds have no historical basis for predicting the likelihood of any such claims.

**Recent accounting pronouncements and regulatory updates**

*Accounting Standards Update 2023-09 Income Taxes (Topic 740)*

In December 2023, the FASB issued Accounting Standards Update No. 2023-09 Income Taxes (Topic 740) Improvements to Income Tax Disclosures. The amendments were issued to enhance the transparency and decision usefulness of income tax disclosures primarily related to rate reconciliation and income taxes paid information. The amendments are effective for annual periods beginning after December 15, 2024, with early adoption permitted. Management expects that the adoption of the amendments will not have a material impact on its financial statements.

Note 3. Fees and other transactions with affiliates

**Management services fees**

Prior to July 7, 2025, CWAM was the Investment Manager and furnished investment supervision to the Funds and was responsible for the overall management of the Funds' business affairs.

Prior to April 1, 2025, CWAM furnished investment advisory services to the Funds under an investment advisory agreement (the Advisory Agreement) and provided administrative services to the Funds under a separate administrative services agreement (the Administration Agreement). Effective April 1, 2025, the Funds entered into a new management services agreement (the Management Agreement) that combined the management services fee that was previously paid under the Advisory Agreement with the administrative services fee that was previously paid under the Administration Agreement. On June 26, 2025, the Funds' Board of Trustees approved a Novation of Management Agreement pursuant to which all rights, duties and obligations under the Funds' then-current Management Agreement with CWAM transferred to its parent company Columbia Management on July 7, 2025. Prior to July, 7, 2025, Columbia Management was the sub-administrator of the Funds and the investment adviser of each of the other Columbia funds except for each series of Columbia Funds Variable Series Trust (formerly Wanger Advisors Trust). The services provided to, and management fees paid by, the Funds did not change as a result of this transfer and the current portfolio managers of the Funds continued to manage the Funds after the transition.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

For the period from January 1, 2025 through February 28, 2025, CWAM received an advisory fee based on each Fund's daily net assets that declined as each Fund's net assets increased at the following annual rates:

---

| | | | |
|:---|:---|:---|:---|
|  | **High (%)** | **Low (%)** | &nbsp;&nbsp;&nbsp; **Annualized** <br>**effective advisory** <br>**fee rate (%)**<br>|
| Columbia Acorn<sup>®</sup> Fund | 0.74 | &nbsp;&nbsp;&nbsp;&nbsp;0.63 | &nbsp;&nbsp;&nbsp;&nbsp;0.69 |
| Columbia Acorn International<sup>®</sup> | 1.10 | &nbsp;&nbsp;&nbsp;&nbsp;0.72 | &nbsp;&nbsp;&nbsp;&nbsp;0.86 |
| Columbia Acorn International Select<sup>SM</sup> | 0.89 | &nbsp;&nbsp;&nbsp;&nbsp;0.85 | &nbsp;&nbsp;&nbsp;&nbsp;0.89 |
| Columbia Thermostat Fund<sup>SM</sup> | 0.10 | &nbsp;&nbsp;&nbsp;&nbsp;0.10 | &nbsp;&nbsp;&nbsp;&nbsp;0.10 |
| Columbia Acorn European Fund<sup>SM</sup> | 1.19 | &nbsp;&nbsp;&nbsp;&nbsp;0.74 | &nbsp;&nbsp;&nbsp;&nbsp;1.19 |

---

Effective March 1, 2025, the Board of Trustees approved a reduction in the advisory fee rates payable to CWAM by the Funds, as noted below. For the period March 1, 2025 through March 31, 2025 CWAM received an advisory fee based on each Fund's daily net assets that declined as each Fund's net assets increased at the following annual rates:

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| | | | |
|:---|:---|:---|:---|
|  | **High (%)** | **Low (%)** | &nbsp;&nbsp;&nbsp; **Annualized** <br>**effective advisory** <br>**fee rate (%)**<br>|
| Columbia Acorn<sup>®</sup> Fund | 0.74 | &nbsp;&nbsp;&nbsp;&nbsp;0.61 | &nbsp;&nbsp;&nbsp;&nbsp;0.67 |
| Columbia Acorn International<sup>®</sup> | 0.87 | &nbsp;&nbsp;&nbsp;&nbsp;0.70 | &nbsp;&nbsp;&nbsp;&nbsp;0.81 |
| Columbia Acorn International Select<sup>SM</sup> | 0.82 | &nbsp;&nbsp;&nbsp;&nbsp;0.63 | &nbsp;&nbsp;&nbsp;&nbsp;0.82 |
| Columbia Thermostat Fund<sup>SM</sup> | 0.10 | &nbsp;&nbsp;&nbsp;&nbsp;0.10 | &nbsp;&nbsp;&nbsp;&nbsp;0.10 |
| Columbia Acorn European Fund<sup>SM</sup> | 0.92 | &nbsp;&nbsp;&nbsp;&nbsp;0.74 | &nbsp;&nbsp;&nbsp;&nbsp;0.92 |

---

Advisory fees paid by the Funds for the period January 1, 2025 through March 31, 2025 are included in Management services fees on the Statement of Operations.

For the period April 1, 2025 through June 30, 2025, CWAM received a management services fee based on each Fund's daily net assets that declined as each Fund's net assets increased at the following annual rates:

---

| | | | |
|:---|:---|:---|:---|
|  | **High (%)** | **Low (%)** | &nbsp;&nbsp;&nbsp; **Annualized effective** <br>**management services** <br>**fee rate (%)**<br>|
| Columbia Acorn<sup>®</sup> Fund | 0.790 | &nbsp;&nbsp;&nbsp;&nbsp;0.625 | &nbsp;&nbsp;&nbsp;&nbsp;0.725 |
| Columbia Acorn International<sup>®</sup> | 0.920 | &nbsp;&nbsp;&nbsp;&nbsp;0.715 | &nbsp;&nbsp;&nbsp;&nbsp;0.864 |
| Columbia Acorn International Select<sup>SM</sup> | 0.870 | &nbsp;&nbsp;&nbsp;&nbsp;0.645 | &nbsp;&nbsp;&nbsp;&nbsp;0.870 |
| Columbia Thermostat Fund<sup>SM</sup> | 0.100 | &nbsp;&nbsp;&nbsp;&nbsp;0.100 | &nbsp;&nbsp;&nbsp;&nbsp;0.100 |
| Columbia Acorn European Fund<sup>SM</sup> | 0.970 | &nbsp;&nbsp;&nbsp;&nbsp;0.755 | &nbsp;&nbsp;&nbsp;&nbsp;0.970 |

---

For the period January 1, 2025 through June 30, 2025, the effective blended advisory fee (for the period January 1, 2025 through March 31, 2025) and management services fee (for the period April 1, 2025 through June 30, 2025), as a percentage of each Fund's average daily net assets, were as follows:

---

| | |
|:---|:---|
|  | **Annualized** <br>**effective blended** <br>**fee rate (%)**<br>|
| Columbia Acorn<sup>®</sup> Fund | 0.703 |
| Columbia Acorn International<sup>®</sup> | 0.853 |
| Columbia Acorn International Select<sup>SM</sup> | 0.868 |
| Columbia Thermostat Fund<sup>SM</sup> | 0.100 |
| Columbia Acorn European Fund<sup>SM</sup> | 1.035 |

---

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

**Participating Affiliates** 

The Investment Manager and its investment advisory affiliates (Participating Affiliates), may coordinate in providing services to their clients. These Participating Affiliates, like the Investment Manager, are direct or indirect subsidiaries of Ameriprise Financial and are registered with the appropriate respective regulators and, where required, the Securities and Exchange Commission and the Commodity Futures Trading Commission in the United States. The Investment Manager engages employees of Participating Affiliates to provide portfolio management services to the Funds. These employees provide services to the Investment Manager pursuant to personnel-sharing agreements or other inter-company arrangements and the Funds pay no additional fees and expenses as a result of any such arrangements.

Specifically, pursuant to such arrangements, employees of Participating Affiliates serve as "associated persons" of the Investment Manager and, in this capacity, serve as Fund portfolio managers and provide portfolio management services to the Funds on behalf of the Investment Manager subject to the oversight and supervision of the Investment Manager and the Funds' Chief Compliance Officer, consistent with the investment objectives, policies and limitations set forth in each Fund's prospectus and SAI, and the Investment Manager's and the Funds' compliance policies and procedures.

**Administration fees**

Prior to April 1, 2025, CWAM received an administration fee from the Funds at the following annual rates:

---

| | |
|:---|:---|
| **Columbia Acorn Trust** | **Columbia Acorn Trust** |
| **Aggregate average daily** <br>**net assets of the trust**<br>| **Annual** <br>**fee rate**<br>|
| Up to $8 billion | 0.050% |
| $8 billion to $16 billion | 0.040% |
| $16 billion to $35 billion | 0.030% |
| $35 billion to $45 billion | 0.025% |
| $45 billion and over | 0.015% |

---

For the period January 1, 2025 through March 31, 2025, the annualized effective administration fee rate was 0.050% of each Fund's average daily net assets, with the exception of Columbia Thermostat Fund<sup>SM</sup>. Columbia Thermostat Fund<sup>SM</sup> contractually waived administration fees for the period March 1, 2025 through March 31, 2025. For the period January 1, 2025 through March 31, 2025, the annualized effective administration fee rate, including the impact of administration fee waivers, for Columbia Thermostat Fund<sup>SM</sup> was 0.030% of the Fund's average daily net assets.

**Compensation of Board members** 

Members of the Board of Trustees who are not officers or employees of the Investment Manager or Ameriprise Financial are compensated for their services to the Funds as disclosed in the Statement of Operations. Under a Deferred Compensation Plan (the Deferred Plan), these members of the Board of Trustees may elect to defer payment of up to 100% of their compensation. Deferred amounts are treated as though equivalent dollar amounts had been invested in shares of certain funds managed by the Investment Manager. Each Fund's liability for these amounts is adjusted for market value changes and remains in the Funds until distributed in accordance with the Deferred Plan. All amounts payable under the Deferred Plan constitute a general unsecured obligation of the Funds. The expense for the Deferred Plan, which includes Trustees' fees deferred during the current period as well as any gains or losses on the Trustees' deferred compensation balances as a result of market fluctuations, is included in "Deferred compensation of board members" in the Statement of Operations.

**Compensation of Chief Compliance Officer**

The Board of Trustees has appointed a Chief Compliance Officer for the Funds in accordance with federal securities regulations. As disclosed in the Statement of Operations, a portion of the Chief Compliance Officer's total compensation is allocated to the Funds, along with other allocations to affiliated registered investment companies managed by the Investment Manager and its affiliates, based on relative net assets.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

**Transfer agency fees**

Under a Transfer and Dividend Disbursing Agent Agreement, Columbia Management Investment Services Corp. (the Transfer Agent), an affiliate of the Investment Manager and a wholly-owned subsidiary of Ameriprise Financial, is responsible for providing transfer agency services to the Funds. The Transfer Agent has contracted with SS&C GIDS, Inc. (SS&C GIDS) to serve as sub-transfer agent. The Transfer Agent pays the fees of SS&C GIDS for services as sub-transfer agent and SS&C GIDS is not entitled to reimbursement for such fees from the Funds (with the exception of out-of-pocket fees).

The Funds pay the Transfer Agent a monthly transfer agency fee based on the number or the average value of accounts, depending on the type of account. In addition, the Funds pay the Transfer Agent a fee for shareholder services based on the number of accounts or on a percentage of the average aggregate value of a Fund's shares maintained in omnibus accounts up to the lesser of the amount charged by the financial intermediary or a cap established by the Board of Trustees from time to time.

The Transfer Agent also receives compensation from the Funds for various shareholder services and reimbursements for certain out-of-pocket fees. Total transfer agency fees for Institutional 2 Class and Institutional 3 Class shares are subject to an annual limitation of not more than 0.07% and 0.02%, respectively, of the average daily net assets attributable to each share class. Prior to April 30, 2025, Institutional 2 Class shares were subject to a contractual transfer agency fee annual limitation of not more than 0.05% and Institutional 3 Class shares were subject to a contractual transfer agency fee annual limitation of not more than 0.00% of the average daily net assets attributable to each share class for Columbia Acorn International Select<sup>SM</sup>. In addition, prior to April 30, 2025, Institutional 2 Class shares were subject to a contractual transfer agency fee annual limitation of not more than 0.04% and Institutional 3 Class shares were subject to a contractual transfer agency fee annual limitation of not more than 0.00% of the average daily net assets attributable to each share class for Columbia Thermostat Fund<sup>SM</sup>.

For the six months ended June 30, 2025, each Fund's annualized effective transfer agency fee rate as a percentage of average daily net assets was as follows:

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **Fund**  | **Class A** <br>**(%)**<br>| **Class C** <br>**(%)**<br>| **Institutional** <br>**Class (%)**<br>| **Institutional 2** <br>**Class (%)**<br>| **Institutional 3** <br>**Class (%)**<br>| **Class S** <br>**(%)**<br>|
| Columbia Acorn<sup>®</sup> Fund | 0.09 | 0.08 | 0.09 | 0.05 | 0.01 | 0.09 |
| Columbia Acorn International<sup>®</sup> | 0.11 | &nbsp;&nbsp; — | 0.11 | 0.06 | 0.01 | 0.11 |
| Columbia Acorn International Select<sup>SM</sup> | 0.20 | &nbsp;&nbsp; — | 0.20 | 0.05 | 0.00 | 0.20 |
| Columbia Thermostat Fund<sup>SM</sup> | 0.09 | 0.09 | 0.09 | 0.05 | 0.00 | 0.09 |
| Columbia Acorn European Fund<sup>SM</sup> | 0.13 | &nbsp;&nbsp; — | 0.13 | &nbsp;&nbsp; — | &nbsp;&nbsp; — | &nbsp;&nbsp; — |

---

An annual minimum account balance fee of $20 may apply to certain accounts with a value below the applicable share class's initial minimum investment requirements to reduce the impact of small accounts on transfer agency fees. These minimum account balance fees are remitted to the Funds and recorded as part of expense reductions in the Statement of Operations. For the six months ended June 30, 2025, no minimum account balance fees were charged by the Funds.

**Distribution and service fees**

The Funds have entered into an agreement with Columbia Management Investment Distributors, Inc. (the Distributor), an affiliate of the Investment Manager and a wholly-owned subsidiary of Ameriprise Financial, for distribution and shareholder services. The Board of Trustees has approved, and the Funds have adopted, distribution and shareholder service plans (the Plans) applicable to certain share classes, which set the distribution and service fees for the Funds. These fees are calculated daily and are intended to compensate the Distributor and/or eligible selling and/or servicing agents for selling shares of the Funds and providing services to investors.

Under the Plans, the Funds pay a monthly service fee to the Distributor at the maximum annual rate of 0.25% of the average daily net assets attributable to Class A and Class C shares of the Funds. Also under the Plans, the Funds pay a monthly distribution fee to the Distributor at the maximum annual rate of 0.75% of the average daily net assets attributable to Class C shares of the Funds.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

**Sales charges** 

Sales charges, including front-end charges and contingent deferred sales charges (CDSCs), received by the Distributor for distributing Fund shares for the six months ended June 30, 2025, if any, are listed below:

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Front End (%)** | **Front End (%)** | **CDSC (%)** | **Amount ($)** | **Amount ($)** |
| **Fund**  | **Class A**  | **Class C**  | **Class C**  | **Class A**  | **Class C**  |
| Columbia Acorn<sup>®</sup> Fund | 5.75 | &nbsp;&nbsp; —<br> 0.50 - 1.00 <br><sup>(a)</sup><br>| 1.00 <br><sup>(b)</sup><br>| &nbsp;&nbsp; 22679 | &nbsp;&nbsp; 361 |
| Columbia Acorn International<sup>®</sup> | 5.75 | &nbsp;&nbsp; —<br> 0.50 - 1.00 <br><sup>(a)</sup><br>| 1.00 <br><sup>(b)</sup><br>| &nbsp;&nbsp; 8498 | &nbsp;&nbsp; — |
| Columbia Acorn International Select<sup>SM</sup> | 5.75 | &nbsp;&nbsp; —<br> 0.50 - 1.00 <br><sup>(a)</sup><br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 7768 | &nbsp;&nbsp; — |
| Columbia Thermostat Fund<sup>SM</sup> | 5.75 | &nbsp;&nbsp; —<br> 0.50 - 1.00 <br><sup>(a)</sup><br>| 1.00 <br><sup>(b)</sup><br>| &nbsp;&nbsp; 70717 | &nbsp;&nbsp; 2184 |
| Columbia Acorn European Fund<sup>SM</sup> | 5.75 | &nbsp;&nbsp; —<br> 0.50 - 1.00 <br><sup>(a)</sup><br>| &nbsp;&nbsp; — | &nbsp;&nbsp; 4244 | &nbsp;&nbsp; — |

---

&nbsp;&nbsp;&nbsp;&nbsp;(a) This charge is imposed on certain investments of between $1 million and $50 million
 redeemed within 18 months after purchase, as follows: 1.00% if redeemed within 12 months after purchase, and 0.50% if redeemed more than 12, but less than 18, months
 after purchase, with certain limited exceptions.

&nbsp;&nbsp;&nbsp;&nbsp;(b) This charge applies to redemptions within 12 months after purchase, with certain limited
 exceptions.

The Funds' other share classes are not subject to sales charges.

**Expenses waived/reimbursed by the Investment Manager and its affiliates**

The Investment Manager and certain of its affiliates have contractually agreed to waive fees and/or reimburse expenses (excluding certain fees and expenses described below) for the period(s) disclosed below, unless sooner terminated at the sole discretion of the Board of Trustees, so that each Fund's net operating expenses, after giving effect to fees waived/expenses reimbursed and any balance credits and/or overdraft charges from the Funds' custodian, do not exceed the following annual rate(s) as a percentage of the classes' average daily net assets:

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **March 1, 2025 through April 30, 2027** | **March 1, 2025 through April 30, 2027** | **March 1, 2025 through April 30, 2027** | **March 1, 2025 through April 30, 2027** | **March 1, 2025 through April 30, 2027** | **March 1, 2025 through April 30, 2027** |
| **Fund** | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class A** <br>**(%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class C** <br>**(%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 2** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 3** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class S** <br>**(%)**<br>|
| Columbia Acorn<sup>®</sup> Fund | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.07 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.82 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.82 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.78 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.74 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.82 |
| Columbia Acorn International<sup>®</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.22 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.97 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.89 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.84 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.97 |
| Columbia Thermostat Fund<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.50 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.25 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.25 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.20 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.16 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.25 |

---

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Prior to March 1, 2025** | **Prior to March 1, 2025** | **Prior to March 1, 2025** | **Prior to March 1, 2025** | **Prior to March 1, 2025** | **Prior to March 1, 2025** |
| **Fund** | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class A** <br>**(%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class C** <br>**(%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 2** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 3** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class S** <br>**(%)**<br>|
| Columbia Acorn<sup>®</sup> Fund | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.08 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.83 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.83 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.80 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.75 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.83 |
| Columbia Acorn International<sup>®</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.23 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.98 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.92 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.88 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.98 |
| Columbia Thermostat Fund<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.50 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.25 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.25 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.20 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.16 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.25 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **May 1, 2025 through April 30, 2026** | **May 1, 2025 through April 30, 2026** | **May 1, 2025 through April 30, 2026** | **May 1, 2025 through April 30, 2026** | **May 1, 2025 through April 30, 2026** |
| **Fund** | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class A** <br>**(%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 2** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 3** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class S** <br>**(%)**<br>|
| Columbia Acorn International Select<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.11 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.86 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.72 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.67 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.86 |
| Columbia Acorn European Fund<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.31 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.06 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **March 1, 2025 through April 30, 2025** | **March 1, 2025 through April 30, 2025** | **March 1, 2025 through April 30, 2025** | **March 1, 2025 through April 30, 2025** | **March 1, 2025 through April 30, 2025** |
| **Fund** | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class A** <br>**(%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 2** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 3** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class S** <br>**(%)**<br>|
| Columbia Acorn International Select<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.14 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.89 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.75 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.70 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.89 |
| Columbia Acorn European Fund<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.37 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.12 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A |

---

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Prior to March 1, 2025** | **Prior to March 1, 2025** | **Prior to March 1, 2025** | **Prior to March 1, 2025** | **Prior to March 1, 2025** |
| **Fund** | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class A** <br>**(%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 2** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Institutional 3** <br>**Class (%)**<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Class S** <br>**(%)**<br>|
| Columbia Acorn International Select<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.24 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.99 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.84 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.79 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0.99 |
| Columbia Acorn European Fund<sup>SM</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.45 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.20 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; N/A |

---

Under the agreement governing these fee waivers and/or expense reimbursement arrangements, the following fees and expenses are excluded from the waiver/reimbursement commitment, and therefore will be paid by each Fund, if applicable: taxes (including foreign transaction taxes), expenses associated with investments in affiliated and non-affiliated pooled investment vehicles (including mutual funds and exchange-traded funds), transaction costs and brokerage commissions, costs related to any securities lending program, dividend expenses associated with securities sold short, inverse floater program fees and expenses, transaction charges and interest on borrowed money, interest, costs associated with shareholder meetings, infrequent and/or unusual expenses and any other expenses the exclusion of which is specifically approved by the Board of Trustees. This agreement may be modified or amended only with approval from the Investment Manager, certain of its affiliates and the Fund. In addition to the contractual agreement, the Investment Manager and certain of its affiliates have voluntarily agreed to waive fees and/or reimburse Columbia Acorn International<sup>®</sup> expenses (excluding certain fees and expenses described above) so that Columbia Acorn International<sup>®</sup> level expenses (expenses directly attributable to Columbia Acorn International<sup>®</sup> and not to a specific share class) are waived proportionately across all share classes, but Columbia Acorn International<sup>®</sup> net operating expenses shall not exceed the contractual annual rates listed in the table above. This arrangement may be revised or discontinued at any time. Any fees waived and/or expenses reimbursed under the expense reimbursement arrangements described above are not recoverable by the Investment Manager or its affiliates in future periods. Reflected in the contractual cap commitment, prior to April 30, 2025, is the Transfer Agent's contractual agreement to limit total transfer agency fees to an annual rate of not more than 0.05% for Institutional 2 Class and 0.00% for Institutional 3 of the average daily net assets attributable to each share class for Columbia Acorn International Select<sup>SM</sup>. In addition, reflected in the contractual cap commitment, prior to April 30, 2025, is the Transfer Agent's contractual agreement to limit total transfer agency fees to an annual rate of not more than 0.04% for Institutional 2 Class and 0.00% for Institutional 3 of the average daily net assets attributable to each share class for Columbia Thermostat Fund<sup>SM</sup>.

Note 4. Federal tax information

The timing and character of income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP because of temporary or permanent book to tax differences.

At June 30, 2025, the approximate cost of all investments for federal income tax purposes and the aggregate gross approximate unrealized appreciation and depreciation based on that cost was:

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fund**  | **Tax cost ($)** | &nbsp;&nbsp;&nbsp; **Gross** <br>**unrealized** <br>**appreciation ($)**<br>| &nbsp;&nbsp;&nbsp; **Gross** <br>**unrealized** <br>&nbsp;&nbsp;&nbsp;&nbsp;**(depreciation) ($)**<br>| &nbsp;&nbsp;&nbsp; **Net unrealized** <br>**appreciation ($)**<br>|
| Columbia Acorn<sup>®</sup> Fund | 2196261000 | &nbsp;&nbsp;&nbsp;&nbsp; 491599000 | &nbsp;&nbsp;&nbsp;&nbsp; (158182000)<br>| &nbsp;&nbsp;&nbsp;&nbsp; 333417000 |
| Columbia Acorn International<sup>®</sup> | 629502000 | &nbsp;&nbsp;&nbsp;&nbsp; 317559000 | &nbsp;&nbsp;&nbsp;&nbsp; (21584000)<br>| &nbsp;&nbsp;&nbsp;&nbsp; 295975000 |
| Columbia Acorn International Select<sup>SM</sup> | 162143000 | &nbsp;&nbsp;&nbsp;&nbsp; 50963000 | &nbsp;&nbsp;&nbsp;&nbsp; (10224000)<br>| &nbsp;&nbsp;&nbsp;&nbsp; 40739000 |
| Columbia Thermostat Fund<sup>SM</sup> | 1144031000 | &nbsp;&nbsp;&nbsp;&nbsp; 105457000 | &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; 105457000 |
| Columbia Acorn European Fund<sup>SM</sup> | 34377000 | &nbsp;&nbsp;&nbsp;&nbsp; 7500000 | &nbsp;&nbsp;&nbsp;&nbsp; (1275000)<br>| &nbsp;&nbsp;&nbsp;&nbsp; 6225000 |

---

Tax cost of investments and unrealized appreciation/(depreciation) may also include timing differences that do not constitute adjustments to tax basis.

The following capital loss carryforwards, determined at December 31, 2024, may be available to reduce future net realized gains on investments, if any, to the extent permitted by the Internal Revenue Code.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

---

| | | | |
|:---|:---|:---|:---|
| **Fund**  | **No expiration** <br>**short-term ($)**<br>| &nbsp;&nbsp;&nbsp; **No expiration** <br>**long-term ($)**<br>| **Total ($)** |
| Columbia Acorn<sup>®</sup> Fund  | (180977174)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (1203843)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (182181017)<br>|
| Columbia Acorn International<sup>®</sup> | (46612186)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (26269099)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (72881285)<br>|
| Columbia Acorn International Select<sup>SM</sup> | (9143290)<br>| &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (9143290)<br>|
| Columbia Thermostat Fund<sup>SM</sup> |  | &nbsp;&nbsp;&nbsp;&nbsp; (116858166)<br>| &nbsp;&nbsp;&nbsp;&nbsp; (116858166)<br>|
| Columbia Acorn European Fund<sup>SM</sup> | (5586840)<br>| &nbsp;&nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp;&nbsp; (5586840)<br>|

---

Under current tax rules, regulated investment companies can elect to treat certain late-year ordinary losses incurred and post-October capital losses (capital losses realized after October 31) as arising on the first day of the following taxable year. The Funds will elect to treat the following late-year ordinary losses and post-October capital losses at December 31, 2024 as arising on January 1, 2025.

---

| | | |
|:---|:---|:---|
| **Fund**  | **Late year** <br>**ordinary losses ($)**<br>| &nbsp;&nbsp;&nbsp; **Post-October** <br>**capital losses ($)**<br>|
| Columbia Acorn European Fund<sup>SM</sup> | 40144 | &nbsp;&nbsp;&nbsp;&nbsp; — |

---

Management of the Funds has concluded that there are no significant uncertain tax positions in the Funds that would require recognition in the financial statements. However, management's conclusion may be subject to review and adjustment at a later date based on factors including, but not limited to, new tax laws, regulations, and administrative interpretations (including relevant court decisions). Generally, the Funds' federal tax returns for the prior three fiscal years remain subject to examination by the Internal Revenue Service.

Note 5. Portfolio information

For the six months ended June 30, 2025, the cost of purchases and proceeds from sales of securities, excluding short-term investments and derivatives, if any, for each Fund aggregated to:

---

| | | |
|:---|:---|:---|
|  | **Purchases** <br>**($)**<br>| &nbsp;&nbsp;&nbsp; **Proceeds** <br>**from sales** <br>**($)**<br>|
| Columbia Acorn<sup>®</sup> Fund | 1061238667 | &nbsp;&nbsp;&nbsp;&nbsp; 1215271847 |
| Columbia Acorn International<sup>®</sup> | 75193764 | &nbsp;&nbsp;&nbsp;&nbsp; 171311319 |
| Columbia Acorn International Select<sup>SM</sup> | 17006159 | &nbsp;&nbsp;&nbsp;&nbsp; 26247657 |
| Columbia Thermostat Fund<sup>SM</sup> | 720351481 | &nbsp;&nbsp;&nbsp;&nbsp; 741703078 |
| Columbia Acorn European Fund<sup>SM</sup> | 21025980 | &nbsp;&nbsp;&nbsp;&nbsp; 28981712 |

---

The amount of purchase and sale activity impacts the portfolio turnover rate reported in the Financial Highlights.

Note 6. Affiliated money market fund

Each Fund may invest in Columbia Short-Term Cash Fund, an affiliated money market fund established for the exclusive use by each Fund and other affiliated funds (the Affiliated MMF). The income earned by the Funds from such investments is included as Dividends - affiliated issuers in the Statement of Operations. As an investing fund, each Fund indirectly bears its proportionate share of the expenses of the Affiliated MMF. The Affiliated MMF prices its shares with a floating net asset value. The Securities and Exchange Commission has adopted amendments to money market fund rules requiring institutional prime money market funds like the Affiliated MMF to be subject to a discretionary liquidity fee of up to 2% if the imposition of such a fee is determined to be in the best interest of the Affiliated MMF and to a mandatory liquidity fee if daily net redemptions exceed 5% of net assets.

Note 7. Line of credit

Each Fund has access to a revolving credit facility with a syndicate of banks led by JPMorgan Chase Bank, N.A., Citibank, N.A. and Wells Fargo Bank, N.A. whereby the Fund may borrow for the temporary funding of shareholder redemptions or for other temporary or emergency purposes. Pursuant to an October 24, 2024 amendment and restatement, the credit facility, which is an agreement between the Fund and certain other funds managed by the Investment Manager or an affiliated

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

investment manager, severally and not jointly, permits aggregate borrowings up to $900 million. Interest is currently charged to each participating fund based on its borrowings at a rate equal to the higher of (i) the federal funds effective rate, (ii) the secured overnight financing rate plus 0.10% and (iii) the overnight bank funding rate, plus 1.00% in each case. Each borrowing under the credit facility matures no later than 60 days after the date of borrowing. The Fund also pays a commitment fee equal to its pro rata share of the unused amount of the credit facility at a rate of 0.15% per annum. The commitment fee is included in other expenses in the Statement of Operations. This agreement expires annually in October unless extended or renewed. Prior to the October 24, 2024 amendment and restatement, each Fund had access to a revolving credit facility with a syndicate of banks led by JPMorgan Chase Bank, N.A., Citibank, N.A. and Wells Fargo Bank, N.A. which permitted collective borrowings up to $900 million. Interest was charged to each participating fund based on its borrowings at a rate equal to the higher of (i) the federal funds effective rate, (ii) the secured overnight financing rate plus 0.10% and (iii) the overnight bank funding rate, plus 1.00% in each case.

During the six months ended June 30, 2025, the following Funds had borrowings:

---

| | | | |
|:---|:---|:---|:---|
| **Fund** | **Average loan** <br>**balance ($)**<br>| &nbsp;&nbsp;&nbsp; **Weighted average** <br>**interest rate (%)**<br>| &nbsp;&nbsp;&nbsp; **Days** <br>**outstanding**<br>|
| Columbia Acorn International<sup>®</sup> | 4680000 | &nbsp;&nbsp;&nbsp;&nbsp;5.41 | &nbsp;&nbsp;&nbsp;&nbsp; 5 |
| Columbia Acorn International Select<sup>SM</sup> | 200000 | &nbsp;&nbsp;&nbsp;&nbsp;5.38 | &nbsp;&nbsp;&nbsp;&nbsp; 2 |
| Columbia Thermostat Fund<sup>SM</sup> | 900000 | &nbsp;&nbsp;&nbsp;&nbsp;5.39 | &nbsp;&nbsp;&nbsp;&nbsp; 4 |
| Columbia Acorn European Fund<sup>SM</sup> | 200000 | &nbsp;&nbsp;&nbsp;&nbsp;5.44 | &nbsp;&nbsp;&nbsp;&nbsp; 3 |

---

Interest expense incurred by the Funds is recorded as Line of credit interest in the Statement of Operations. Columbia Acorn International<sup>®</sup>, Columbia Acorn International Select<sup>SM</sup> , Columbia Thermostat Fund<sup>SM</sup> and Columbia Acorn European Fund<sup>SM</sup> had no outstanding borrowings at June 30, 2025.

Note 8. Significant risks

**Financials sector risk** 

Columbia Acorn European Fund<sup>SM</sup> is more susceptible to the particular risks that may affect companies in the financials sector than if they were invested in a wider variety of companies in unrelated sectors. Companies in the financials sector are subject to certain risks, including the risk of regulatory change, decreased liquidity in credit markets and unstable interest rates. Such companies may have concentrated portfolios, such as a high level of loans to real estate developers, which makes them vulnerable to economic conditions that affect that industry. Performance of such companies may be affected by competitive pressures and exposure to investments, agreements and counterparties, including credit products that, under certain circumstances, may lead to losses (e.g., subprime loans). Companies in the financials sector are subject to extensive governmental regulation that may limit the amount and types of loans and other financial commitments they can make, and interest rates and fees that they may charge. In addition, profitability of such companies is largely dependent upon the availability and the cost of capital.

**Foreign securities and emerging market countries risk** 

Investing in foreign securities may involve heightened risks relative to investments in U.S. securities. Investing in foreign securities subjects the Funds to the risks associated with the issuer's country of organization and places of business operations, including risks associated with political, regulatory, economic, social, diplomatic and other conditions or events occurring in the country or region, which may result in significant market volatility. In addition, certain foreign securities may be more volatile and less liquid than U.S. securities. Investing in emerging markets may increase these risks and expose the Funds to elevated risks associated with increased inflation, deflation or currency devaluation. To the extent that Columbia Acorn International<sup>®</sup>, Columbia Acorn International Select<sup>SM</sup> and Columbia Acorn European Fund<sup>SM</sup> concentrate their investment exposure to any one or a few specific countries, the Funds will be particularly susceptible to the risks associated with the conditions, events or other factors impacting those countries or regions and may, therefore, have a greater risk than that of a fund that is more geographically diversified. The financial information and disclosure made available by issuers of emerging market securities may be considerably less reliable than publicly available information about other foreign securities. The Public Company Accounting Oversight Board, which regulates auditors of U.S. public companies, is unable to inspect audit work papers in certain foreign countries. Investors in foreign countries often have limited rights and few practical remedies to pursue shareholder claims, including class actions or fraud claims, and the ability of the U.S. Securities

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

and Exchange Commission, the U.S. Department of Justice and other authorities to bring and enforce actions against foreign issuers or foreign persons is limited.

**Geographic focus risk** 

Columbia Acorn International<sup>®</sup>, Columbia Acorn International Select<sup>SM</sup> and Columbia Acorn European Fund<sup>SM</sup> may be particularly susceptible to risks related to economic, political, regulatory or other events or conditions affecting issuers and countries within the specific geographic regions in which the Funds invest. The Funds' net asset value may be more volatile than the net asset value of a more geographically diversified fund.

*Asia Pacific Region.* Columbia Acorn International<sup>®</sup>and Columbia Acorn International Select<sup>SM</sup> are particularly susceptible to economic, political, regulatory or other events or conditions affecting issuers and countries in the Asia Pacific region. Many of the countries in the region are considered underdeveloped or developing, including from a political, economic and/or social perspective, and may have relatively unstable governments and economies based on limited business, industries and/or natural resources or commodities. Events in any one country within the region may impact other countries in the region or the region as a whole. As a result, events in the region will generally have a greater effect on the Funds than if the Funds were more geographically diversified. This could result in increased volatility in the value of the Funds' investments and losses for the Funds. Also, securities of some companies in the region can be less liquid than U.S. or other foreign securities, potentially making it difficult for the Funds to sell such securities at a desirable time and price.

*Europe.* Columbia Acorn International<sup>®</sup>, Columbia Acorn International Select<sup>SM</sup> and Columbia Acorn European Fund<sup>SM</sup> are particularly susceptible to risks related to economic, political, regulatory or other events or conditions, including acts of war or other conflicts in the region, affecting issuers and countries in Europe. Countries in Europe are often closely connected and interdependent, and events in one European country can have an adverse impact on, and potentially spread to, other European countries. In addition, significant private or public debt problems in a single European Union (EU) country can pose economic risks to the EU as a whole. As a result, the Funds' net asset value may be more volatile than the net asset value of a more geographically diversified fund. If securities of issuers in Europe fall out of favor, it may cause the Funds to underperform other funds that do not focus their investments in this region of the world. Uncertainty caused by the departure of the United Kingdom (UK) from the EU, which occurred in January 2020, could have negative impacts on the UK and EU, as well as other European economies and the broader global economy. These could include negative impacts on currencies and financial markets as well as increased volatility and illiquidity, and potentially lower economic growth in markets in Europe, which could adversely affect the value of your investment in the Fund.

*Japan.* Columbia Acorn International<sup>®</sup> and Columbia Acorn International Select<sup>SM</sup> are particularly susceptible to the social, political, economic, regulatory and other conditions or events that may affect Japan's economy. The Japanese economy is heavily dependent upon international trade, including, among other things, the export of finished goods and the import of oil and other commodities and raw materials. Because of its trade dependence, the Japanese economy is particularly exposed to the risks of currency fluctuation, foreign trade policy and regional and global economic disruption, including the risk of increased tariffs, embargoes, and other trade limitations or factors. Strained relationships between Japan and its neighboring countries, including China, South Korea and North Korea, based on historical grievances, territorial disputes, and defense concerns, may also cause uncertainty in Japanese markets. As a result, additional tariffs, other trade barriers, or boycotts may have an adverse impact on the Japanese economy. Japanese government policy has been characterized by economic regulation, intervention, protectionism and large government deficits. The Japanese economy is also challenged by an unstable financials sector, highly leveraged corporate balance sheets and extensive cross-ownership among major corporations. Structural social and labor market changes, including an aging workforce, population decline and traditional aversion to labor mobility may adversely affect Japan's economic competitiveness and growth potential. The potential for natural disasters, such as earthquakes, volcanic eruptions, typhoons and tsunamis, could also have significant negative effects on Japan's economy. As a result of the Fund's investment in Japanese securities, the Fund's net asset value may be more volatile than the net asset value of a more geographically diversified fund. If securities of issuers in Japan fall out of favor, it may cause the Funds to underperform other funds that do not focus their investments in Japan.

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

**Health care sector risk**

Columbia Acorn<sup>®</sup> Fund is more susceptible to the particular risks that may affect companies in the health care sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the health care sector are subject to certain risks, including restrictions on government reimbursement for medical expenses, government approval of medical products and services, competitive pricing pressures, and the rising cost of medical products and services (especially for companies dependent upon a relatively limited number of products or services). Performance of such companies may be affected by factors including government regulation, obtaining and protecting patents (or the failure to do so), product liability and other similar litigation as well as product obsolescence.

**Industrial sector risk** 

Columbia Acorn<sup>®</sup> Fund, Columbia Acorn International<sup>®</sup>, Columbia Acorn International Select<sup>SM</sup> and Columbia Acorn European Fund<sup>SM</sup> are more susceptible to the particular risks that may affect companies in the industrials sector than if they were invested in a wider variety of companies in unrelated sectors. Companies in the industrials sector are subject to certain risks, including changes in supply and demand for their specific product or service and for industrial sector products in general, including decline in demand for such products due to rapid technological developments and frequent new product introduction. Performance of such companies may be affected by factors including government regulation, world events, economic conditions and risks for environmental damage and product liability claims.

**Information technology sector risk** 

Columbia Acorn International<sup>®</sup> is more susceptible to the particular risks that may affect companies in the information technology sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the information technology sector are subject to certain risks, including the risk that new services, equipment or technologies will not be accepted by consumers and businesses or will become rapidly obsolete. Performance of such companies may be affected by factors including obtaining and protecting patents (or the failure to do so) and significant competitive pressures, including aggressive pricing of their products or services, new market entrants, competition for market share and short product cycles due to an accelerated rate of technological developments. Such competitive pressures may lead to limited earnings and/or falling profit margins. As a result, the value of their securities may fall or fail to rise. In addition, many information technology sector companies have limited operating histories and prices of these companies' securities historically have been more volatile than other securities, especially over the short term. Some companies in the information technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action, which could negatively impact the value of their securities.

**Market risk**

The Funds may incur losses due to declines in the value of one or more securities in which they invest. These declines may be due to factors affecting a particular issuer, or the result of, among other things, political, regulatory, market, economic or social developments affecting the relevant market(s) more generally. In addition, turbulence in financial markets and reduced liquidity in equity, credit and/or fixed income markets may negatively affect many issuers, which could adversely affect the Funds' ability to price or value hard-to-value assets in thinly traded and closed markets and could cause significant redemptions and operational challenges. Global economies and financial markets are increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide. As a result, local, regional or global events such as terrorism, war, other conflicts, natural disasters, disease/virus outbreaks and epidemics or other public health issues, recessions, depressions or other events – or the potential for such events – could have a significant negative impact on global economic and market conditions.

**Shareholder concentration risk**

At June 30, 2025, certain shareholder accounts owned more than 20% of the outstanding shares of one or more of the Funds. For unaffiliated shareholder accounts, the Funds have no knowledge about whether any portion of those shares were owned beneficially. Fund shares sold to or redeemed by these accounts may have a significant effect on the operations of the Funds. In the case of a large redemption, the Fund may be forced to sell investments at inopportune times, including its

Columbia Acorn Trust \| 2025

------

Notes to Financial Statements (continued)

June 30, 2025 (Unaudited)

liquid positions, which may result in Fund losses and the Fund holding a higher percentage of less liquid positions. Large redemptions could result in decreased economies of scale and increased operating expenses for non-redeeming Fund shareholders.

The number of accounts and aggregate percentages of shares outstanding held therein were as follows:

---

| | |
|:---|:---|
| **Fund**  | **Percentage of** <br>**shares** <br>**outstanding** <br>**held —** <br>**affiliated (%)**<br>|
| Columbia Acorn<sup>®</sup> Fund |  |
| Columbia Acorn International<sup>®</sup> |  |
| Columbia Acorn International Select<sup>SM</sup> | 26.0 |
| Columbia Thermostat Fund<sup>SM</sup> | 22.9 |
| Columbia Acorn European Fund<sup>SM</sup> | 32.4 |

---

**Small- and mid-cap company risk**

Columbia Acorn<sup>®</sup> Fund, Columbia Acorn International<sup>®</sup>, Columbia Acorn International Select<sup>SM</sup> and Columbia Acorn European Fund<sup>SM</sup> investments in small- and mid-capitalization companies (small- and mid-cap companies) often involve greater risks than investments in larger, more established companies (larger companies) because small- and mid-cap companies tend to have less predictable earnings and may lack the management experience, financial resources, product diversification and competitive strengths of larger companies. Securities of small- and mid-cap companies may be less liquid and more volatile than the securities of larger companies.

Note 9. Subsequent events

Management has evaluated the events and transactions that have occurred through the date the financial statements were issued. Other than as noted in Note 2 and Note 3 above, there were no items requiring adjustment of the financial statements or additional disclosure.

Note 10. Information regarding pending and settled legal proceedings

Ameriprise Financial and certain of its affiliates are involved, in the normal course of business, in legal proceedings that include regulatory inquiries, arbitration and litigation (including class actions) concerning matters arising in connection with the conduct of their activities as part of a diversified financial services firm. Ameriprise Financial believes that the Funds are not currently the subject of, and that neither Ameriprise Financial nor any of its affiliates are the subject of, any pending legal, arbitration or regulatory proceedings that are likely to have a material adverse effect on the Funds or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Funds. Ameriprise Financial is required to make quarterly (10-Q), annual (10-K) and, as necessary, 8-K filings with the Securities and Exchange Commission (SEC) on legal and regulatory matters that relate to Ameriprise Financial and its affiliates. Copies of these filings may be obtained by accessing the SEC website at www.sec.gov.

There can be no assurance that these matters, or the adverse publicity associated with them, will not result in increased Fund redemptions, reduced sale of Fund shares or other adverse consequences to the Funds. Further, although we believe proceedings are not likely to have a material adverse effect on the Funds or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Funds, these proceedings are subject to uncertainties and, as such, it is inherently difficult to determine whether any loss is probable or even reasonably possible, or to reasonably estimate the amount of any loss that may result from such matters. An adverse outcome in one or more of these proceedings could result in adverse judgments, settlements, fines, penalties or other relief, and may lead to further claims, examinations, adverse publicity or reputational damage, each of which could have a material adverse effect on the consolidated financial condition or results of operations or financial condition of Ameriprise Financial or one or more of its affiliates that provide services to the Funds.

Columbia Acorn Trust \| 2025

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Results of Meeting of Shareholders

(Unaudited)

At a Joint Special Meeting of Shareholders held on February 26, 2025, shareholders of Columbia Acorn Trust elected each of the fifteen nominees for trustee to the Board of Trustees of Columbia Acorn Trust, each to hold office until he or she dies, retires, resigns or is removed or, if sooner, until the election and qualification of his or her successor, as follows:

---

| | | | |
|:---|:---|:---|:---|
| **Trustee** | **Votes for** | **Votes withheld** | **Abstentions** |
| George S. Batejan | &nbsp;&nbsp;&nbsp;&nbsp; 205615145 | &nbsp;&nbsp;&nbsp;&nbsp; 14931583 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Daniel J. Beckman | &nbsp;&nbsp;&nbsp;&nbsp; 203656312 | &nbsp;&nbsp;&nbsp;&nbsp; 16890417 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Kathleen Blatz | &nbsp;&nbsp;&nbsp;&nbsp; 205888392 | &nbsp;&nbsp;&nbsp;&nbsp; 14658336 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Pamela G. Carlton | &nbsp;&nbsp;&nbsp;&nbsp; 205814242 | &nbsp;&nbsp;&nbsp;&nbsp; 14732486 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Janet Langford Carrig | &nbsp;&nbsp;&nbsp;&nbsp; 205925510 | &nbsp;&nbsp;&nbsp;&nbsp; 14621219 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| J. Kevin Connaughton | &nbsp;&nbsp;&nbsp;&nbsp; 206197272 | &nbsp;&nbsp;&nbsp;&nbsp; 14349457 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Olive M. Darragh | &nbsp;&nbsp;&nbsp;&nbsp; 206757668 | &nbsp;&nbsp;&nbsp;&nbsp; 13789060 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Patricia M. Flynn | &nbsp;&nbsp;&nbsp;&nbsp; 205709045 | &nbsp;&nbsp;&nbsp;&nbsp; 14837684 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Brian J. Gallagher | &nbsp;&nbsp;&nbsp;&nbsp; 205784907 | &nbsp;&nbsp;&nbsp;&nbsp; 14761821 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Douglas A. Hacker | &nbsp;&nbsp;&nbsp;&nbsp; 204217674 | &nbsp;&nbsp;&nbsp;&nbsp; 16329055 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Nancy T. Lukitsh | &nbsp;&nbsp;&nbsp;&nbsp; 203953914 | &nbsp;&nbsp;&nbsp;&nbsp; 16592814 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| David M. Moffett | &nbsp;&nbsp;&nbsp;&nbsp; 201809833 | &nbsp;&nbsp;&nbsp;&nbsp; 18736895 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Catherine James Paglia | &nbsp;&nbsp;&nbsp;&nbsp; 203734401 | &nbsp;&nbsp;&nbsp;&nbsp; 16812327 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Natalie A. Trunow | &nbsp;&nbsp;&nbsp;&nbsp; 204536248 | &nbsp;&nbsp;&nbsp;&nbsp; 16010480 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |
| Sandra L. Yeager | &nbsp;&nbsp;&nbsp;&nbsp; 204737943 | &nbsp;&nbsp;&nbsp;&nbsp; 15808786 | &nbsp;&nbsp;&nbsp;&nbsp; 0 |

---

Columbia Acorn Trust \| 2025

------

Approval of Management Agreement

(Unaudited)

APPROVAL OF MANAGEMENT AGREEMENTS WITH COLUMBIA WANGER ASSET MANAGEMENT

Consideration of Management Agreement with Columbia Wanger Asset Management, LLC

At their meeting on March 27, 2025 (the March Meeting), the Board of Trustees (the Board), including the independent Board members (the Independent Trustees), of Columbia Acorn Trust (the Trust) unanimously approved management agreements (the CWAM Management Agreements) between Columbia Wanger Asset Management, LLC (CWAM) and the Trust, on behalf of Columbia Acorn Fund, Columbia Acorn European Fund, Columbia Acorn International, Columbia Acorn International Select, and Columbia Thermostat Fund (the Funds), effective April 1, 2025. Independent legal counsel noted for the Independent Trustees that management was seeking approval of the proposed Management Agreements in place of existing Investment Advisory Agreements and Administrative Services Agreements with CWAM.

At the March Meeting, the Independent Trustees reviewed and discussed the presentation made at the March 26, 2025 Contracts Committee meeting regarding the proposed CWAM Management Agreements. The Independent Trustees considered the differences between each of the CWAM Management Agreements and the existing Investment Advisory Agreements and Administrative Services Agreements with CWAM. The Independent Trustees considered that CWAM had confirmed that the nature and level of the services to be provided under the CWAM Management Agreements would not decrease relative to the services provided under the Investment Advisory Agreements and the Administrative Services Agreements. The Independent Trustees also considered that the aggregate fee to be paid by the Funds would not change, noting that, for each Fund, the management fee rate was proposed to equal the sum of the existing investment management services fee rate and the existing administrative fee rate. It was observed that the combining of the agreements was therefore not material for the Funds' shareholders. The Independent Trustees considered that the Funds' investment management services and administrative fees were considered less than one year ago in connection with the June 2024 renewal of the existing Investment Advisory Agreements and Administrative Services Agreements with CWAM.

The Independent Trustees noted the discussion relating to the renewal and approval of the advisory agreements for the other Funds at the Contracts Committee and Board meetings in June 2024 (the June 2024 Meeting) and, in that connection, the discussion by independent legal counsel of the Board's responsibilities pursuant to Sections 15(c) and 36(b) of the 1940 Act and the factors that should be considered in determining whether to approve or renew an investment management agreement and/or subadvisory agreement. Independent legal counsel further indicated that the Independent Trustees should take into account the variety of written materials and oral presentations they received at this meeting as well as all of the information previously considered at the June 2024 Meeting regarding the proposed renewal of the other Funds' advisory agreements. It was noted that the Board's consideration of the 2025 renewal of the Funds' agreements would be undertaken in June 2025.

The Board reviewed all of the above considerations in reaching its decision to approve each of the

CWAM Management Agreements. In reaching its conclusions, no single factor was determinative. On March 27, 2025, the Board, including all of the Independent Trustees, unanimously approved each of the CWAM Management Agreements.

APPROVAL OF MANAGEMENT AGREEMENTS WITH COLUMBIA MANAGEMENT INVESTMENT ADVISERS

At their meeting on June 26, 2025 (the June Meeting), the Board, including the Independent Trustees, unanimously approved novation agreements assigning the CWAM Management Agreements from CWAM to Columbia Management Investment Advisers, LLC (the Investment Manager, and together with its domestic and global affiliates, Columbia Threadneedle Investments), a wholly-owned subsidiary of Ameriprise Financial, Inc. (Ameriprise Financial), effective July 1, 2025. The Board, including the Independent Trustees, also unanimously approved the continuation through June 30, 2026 of each of the management agreements (the Management Agreements) resulting therefrom. Under the Management Agreements and other similar management agreements, the Investment Manager provides investment advice and other services to the Funds and other funds distributed by Columbia Management Investment Distributors, Inc. (collectively, the Columbia Funds).

On an annual basis, the Board, including the Independent Trustees, considers renewal of the Columbia Funds' management agreements. The Investment Manager prepared detailed reports for the Board and its Contracts Committee (including its Contracts Subcommittee) in March, April and June 2025, including reports providing the results of analyses performed by a third-party data provider, Broadridge Financial Solutions, Inc. (Broadridge), and comprehensive responses by the Investment

Columbia Acorn Trust \| 2025

------

Approval of Management Agreement (continued)

(Unaudited)

Manager to written requests for information by independent legal counsel to the Independent Trustees (Independent Legal Counsel), to assist the Board in making this determination. In addition, throughout the year, the Board (or its committees or subcommittees) regularly meets with portfolio management teams and senior management personnel and reviews information prepared by the Investment Manager addressing the services the Investment Manager provides and Fund performance. The Board also accords appropriate weight to the work, deliberations and conclusions of the various committees (including their subcommittees), such as the Contracts Committee, the Investment Review Committee, the Audit Committee and the Compliance Committee in determining whether to continue the Management Agreements. The Board also evaluated materials provided by CWAM regarding the Funds, and discussed these materials with representatives of the Investment Manager at the Committee and Board meetings held in March and June 2025.

The Board, at the June Meeting, considered the continuation of each Management Agreement through June 30, 2026. At the June Meeting, Independent Legal Counsel reviewed with the Independent Trustees various factors relevant to the Board's consideration of advisory agreements and the Board's legal responsibilities related to such consideration. The Independent Trustees considered such information as they, their legal counsel or the Investment Manager believed reasonably necessary to evaluate and to approve the continuation of each of the Management Agreements. Among other things, the information and factors considered included the following:

• Information on the investment performance of the Funds relative to the performance of a group of mutual funds determined to be comparable to the Funds by Broadridge, as well as performance relative to one or more benchmarks;

• Information on the Funds' management fees and total expenses, including information comparing the Funds' expenses to those of a group of comparable mutual funds, as determined by Broadridge;

• The Investment Manager's agreement to contractually limit or cap total operating expenses for the Funds so that total operating expenses (excluding certain fees and expenses, such as transaction costs and certain other investment related expenses, interest, taxes, acquired fund fees and expenses and infrequent and/or unusual expenses) would not exceed a specified annual rate, as a percentage of the Funds' net assets;

• Terms of the Management Agreements, including the novation agreements (also considered at this meeting);

• Descriptions of other agreements and arrangements with affiliates of the Investment Manager relating to the operations of the Funds, including agreements with respect to the provision of transfer agency and shareholder services to the Funds;

• Descriptions of various services performed by the Investment Manager under the Management Agreements, including portfolio management and portfolio trading practices;

• Information regarding any recently negotiated management fees of similarly-managed portfolios of other institutional clients of the Investment Manager;

• Information regarding the resources of the Investment Manager, including information regarding senior management, portfolio managers and other personnel;

• Information regarding the capabilities of the Investment Manager with respect to compliance monitoring services;

• The profitability to the Investment Manager and its affiliates from their relationships with the Funds; and

• Report provided by the Board's independent fee consultant, JDL Consultants, LLC (JDL).

Following an analysis and discussion of the foregoing, and the factors identified below, the Board, including all of the Independent Trustees, approved the continuation of each of the Management Agreements.

Nature, extent and quality of services provided by the Investment Manager

The Board analyzed various reports and presentations it had received detailing the services performed by the Investment Manager, as well as its history, expertise, resources and relative capabilities, and the qualifications of its personnel.

Columbia Acorn Trust \| 2025

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Approval of Management Agreement (continued)

(Unaudited)

The Board specifically considered the many developments during recent years concerning the services provided by the Investment Manager. Among other things, the Board noted the organization and depth of the equity and credit research departments. The Board further observed the enhancements to the investment risk management department's processes, systems and oversight over the past several years. The Board also took into account the broad scope of services provided by the Investment Manager to the Funds, including, among other services, investment, risk and compliance oversight. The Board also took into account the information it received concerning the Investment Manager's ability to attract and retain key portfolio management personnel and that it has sufficient resources to provide competitive and adequate compensation to investment personnel.

In connection with the Board's evaluation of the overall package of services provided by the Investment Manager, the Board also considered the nature, quality and range of administrative services provided to the Funds by the Investment Manager, as well as the achievements in 2024 in the performance of administrative services, and noted the various enhancements anticipated for 2025. In evaluating the quality of services provided under the Management Agreements, the Board also took into account the organization and strength of the Funds' and their service providers' compliance programs. The Board also reviewed the financial condition of the Investment Manager and its affiliates and each entity's ability to carry out its responsibilities under the Management Agreements and the Funds' other service agreements.

In addition, the Board discussed the acceptability of the terms of the Management Agreements, including the novation agreements (which were not expected to impact the services provided in any material respect). The Board also noted the wide array of legal and compliance services provided to the Funds under the Management Agreements.

After reviewing these and related factors (including investment performance as discussed below), the Board concluded, within the context of their overall conclusions, that the nature, extent and quality of the services provided to the Funds under the Management Agreements supported the continuation of each of the Management Agreements.

Investment performance

The Board carefully reviewed the investment performance of the Funds, including detailed reports providing the results of analyses performed by each of the Investment Manager, Broadridge and JDL collectively showing, for various periods (including since manager inception): (i) the performance of the Funds, (ii) the Funds' performance relative to peers and benchmarks and (iii) the net assets of the Funds. With respect to Columbia Acorn European Fund, Columbia Acorn International, and Columbia Acorn International Select, the Board observed the Funds' underperformance for certain periods, noting that appropriate steps (such as enhancements to the Funds' investment process and changes to the management teams) had been taken in recent years. With respect to Columbia Acorn Fund, the Board observed that the Fund's performance for certain periods ranked above median based on information provided by Broadridge. With respect to Columbia Thermostat Fund, the Board observed that the Fund's performance was well within the range of that of its peers.

The Board also reviewed a description of the third-party data provider's methodology for identifying the Funds' peer groups for purposes of performance and expense comparisons.

The Board also considered the Investment Manager's performance and reputation generally. After reviewing these and related factors, the Board concluded, within the context of their overall conclusions, that the performance of the Funds and the Investment Manager, in light of other considerations, supported the continuation of each of the Management Agreements.

Comparative fees, costs of services provided and the profits realized by the Investment Manager and its affiliates from their relationships with the Funds

The Board reviewed comparative fees and the costs of services provided under the Management Agreements. The Board members considered detailed comparative information set forth in an annual report on fees and expenses, including, among other things, data (based on analyses conducted by Broadridge and JDL) showing a comparison of the Funds' expenses with median expenses paid by funds in its comparative peer universe, as well as data showing the Funds' contribution to the Investment Manager's profitability. With respect to Columbia Acorn Fund, the Board reviewed the fees charged to comparable institutional or other accounts/vehicles managed by the Investment Manager and discussed differences in how the products are managed and operated, thus explaining many of the differences in fees.

Columbia Acorn Trust \| 2025

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Approval of Management Agreement (continued)

(Unaudited)

The Board considered the reports of JDL, which assisted in the Board's analysis of the Funds' performance and expenses and the reasonableness of the Funds' fee rates. With respect to each of Columbia Acorn European Fund and Columbia Acorn International Select, the Board took into account that the Fund's total expense ratio (after considering proposed expense caps/waivers) approximated the peer universe's median expense ratio. With respect to each of Columbia Acorn Fund, Columbia Acorn International, and Columbia Thermostat Fund, the Board took into account that the Fund's total expense ratio (after considering proposed expense caps/waivers) was below the peer universe's median expense ratio shown in the reports.

After reviewing these and related factors, the Board concluded, within the context of their overall conclusions, that the levels of management fees and expenses of the Funds, in light of other considerations, supported the continuation of each of the Management Agreements.

The Board also considered the profitability of the Investment Manager and its affiliates in connection with the Investment Manager providing management services to the Funds. With respect to the profitability of the Investment Manager and its affiliates, the Independent Trustees referred to information discussing the profitability to the Investment Manager and Ameriprise Financial from managing, operating and distributing the Columbia Funds. The Board considered that the profitability generated by the Investment Manager in 2024 had increased from 2023 levels due to a variety of factors, including the increased assets under management of the Columbia Funds. It also took into account the indirect economic benefits flowing to the Investment Manager or its affiliates in connection with managing or distributing the Columbia Funds, such as the enhanced ability to offer various other financial products to Ameriprise Financial customers, soft dollar benefits and overall reputational advantages. The Board noted that the fees paid by the Funds should permit the Investment Manager to offer competitive compensation to its personnel, make necessary investments in its business and earn an appropriate profit. After reviewing these and related factors, the Board concluded, within the context of their overall conclusions, that the costs of services provided and the profitability to the Investment Manager and its affiliates from their relationships with the Funds supported the continuation of each of the Management Agreements.

The Board considered the economies of scale that might be realized as Columbia Thermostat Fund's net asset level grows and took note of the extent to which Fund shareholders might also benefit from such growth. The Board took into account, however, that the Management Agreement for Columbia Thermostat Fund already provides for a relatively low flat fee regardless of the Fund's asset level, and requires Columbia Threadneedle to provide investment advice, as well as administrative, accounting and other services to the Fund.

The Board considered the potential existence of economies of scale in the provision by the Investment Manager of services to the Funds, and whether those economies of scale were shared with Columbia Acorn Fund, Columbia Acorn European Fund, Columbia Acorn International, and Columbia Acorn International Select through breakpoints in investment management fees or other means, such as expense limitation arrangements and additional investments by the Investment Manager in investment, trading, compliance and other resources. The Board considered the economies of scale that might be realized as each such Fund's net asset level grows and took note of the extent to which Fund shareholders might also benefit from such growth. In this regard, the Board took into account that management fees decline as each such Fund's assets exceed various breakpoints, all of which have not been surpassed. The Board observed that the Management Agreements for each of Columbia Acorn Fund, Columbia Acorn European Fund, Columbia Acorn International, and Columbia Acorn International Select thus provides for breakpoints in the management fee rate schedule that allow opportunities for shareholders to realize lower fees as each such Fund's assets grow and that there are additional opportunities through other means for sharing economies of scale with shareholders.

Conclusion

The Board reviewed all of the above considerations in reaching its decision to approve the continuation of each of the Management Agreements. In reaching its conclusions, no single factor was determinative.

On June 26, 2025, the Board, including all of the Independent Trustees, determined that fees payable under the Management Agreements were fair and reasonable in light of the extent and quality of services provided and approved the continuation of the Management Agreements.

Columbia Acorn Trust \| 2025

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P.O. Box 219104

Kansas City, MO 64121-9104

![](imgc59adf692.jpg)

**Please read and consider the investment objectives, risks, charges and expenses for any fund carefully before investing. For a prospectus and summary prospectus, which contains this and other important information about the Funds, go to** 

columbiathreadneedleus.com/investor/**.** The Funds are distributed by Columbia Management Investment Distributors, Inc., member FINRA, and managed by Columbia Management Investment Advisers, LLC.

Columbia Threadneedle Investments<sup>®</sup> (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies. All rights reserved.© 2025 Columbia Management Investment Advisers, LLC.

columbiathreadneedleus.com/investor/

SAR110_12_R01_(08/25)

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Item 8. Changes in and Disagreements with Accountants for Open-End Management Investment Companies.

Not Applicable.

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Item 9. Proxy Disclosures for Open-End Management Investment Companies.

Proxy disclosures for Open-End Management Investment Companies is included in Item 7 of this Form N-CSR.

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Item 10. Remuneration Paid to Directors, Officers, and Others of Open-End Management Investment Companies.

The fees and expenses of the independent trustees are included in "Compensation of board members" and "Deferred compensation of board members" on each Fund's Statement of Operations as part of the Registrant's financial statements filed under Item 7 of this Form N-CSR. Additionally, the compensation paid by the Trust to the Chief Compliance Officer is included in "Compensation of chief compliance officer" on each Fund's Statement of Operations as part of the Registrant's financial statements filed under Item 7 of this Form N-CSR.

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Item 11. Statement Regarding Basis for Approval of Investment Advisory Contract.

Statement regarding basis for approval of Investment Advisory Contract is included in Item 7 of this Form N-CSR.

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Item 12. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.

Not applicable.

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Item 13. Portfolio Managers of Closed-End Management Investment Companies.

Not applicable.

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Item 14. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers.

Not applicable.

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Item 15. Submission of Matters to a Vote of Security Holders.

There were no material changes to the procedures by which shareholders may recommend nominees to the registrant's board of directors implemented since the registrant last provided disclosure as to such procedures in response to the requirements of Item 407(c)(2)(iv) of Regulation S-K or Item 15 of Form N-CSR.

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Item 16. Controls and Procedures.

(a) The registrant's principal executive officer and principal financial officer, based on their evaluation of the registrant's disclosure controls and procedures as of a date within 90 days of the filing of this report, have concluded that such controls and procedures are adequately designed to ensure that information required to be disclosed by the registrant in Form N-CSR is accumulated and communicated to the registrant's management, including the principal executive officer and principal financial officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure.

(b) There was no 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.

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Item 17. Disclosure of Securities Lending Activities for Closed-End Management Investment Companies.

Not applicable.

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Item 18. Recovery of Erroneously Awarded Compensation.

Not applicable.

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Item 19. Exhibits.

(a)(1) Not applicable.

[(a)(2) Certifications pursuant to Rule 30a-2(a) under the Investment Company Act of 1940 (17 CFR 270.30a-2(a)) attached hereto as Exhibit 99.CERT.](302_Certification.htm)

[(b) Certification pursuant to Rule 30a-2(b) under the Investment Company Act of 1940 (17 CFR 270.30a-2(b)) attached hereto as Exhibit 99.906CERT.](906_Certification.htm)

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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.

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| | |
|:---|:---|
| &nbsp;&nbsp;(registrant) | &nbsp;&nbsp;Columbia Acorn Trust |
| &nbsp;&nbsp;By (Signature and Title) | &nbsp;&nbsp;/s/ Daniel J. Beckman |
|  | &nbsp;&nbsp;Daniel J. Beckman, President and Principal Executive Officer |
| &nbsp;&nbsp;Date | &nbsp;&nbsp;August 21, 2025 |

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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.

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| | |
|:---|:---|
| &nbsp;&nbsp;By (Signature and Title) | &nbsp;&nbsp;/s/ Daniel J. Beckman |
|  | &nbsp;&nbsp;Daniel J. Beckman, President and Principal Executive Officer |
| &nbsp;&nbsp;Date | &nbsp;&nbsp;August 21, 2025 |
| &nbsp;&nbsp;By (Signature and Title) | &nbsp;&nbsp; /s/ Michael G. Clarke |
|  | &nbsp;&nbsp;Michael G. Clarke, Chief Financial Officer, |
|  | &nbsp;&nbsp;Principal Financial Officer and Senior Vice President |
| &nbsp;&nbsp;Date | &nbsp;&nbsp;August 21, 2025 |
| &nbsp;&nbsp;By (Signature and Title) | &nbsp;&nbsp;/s/ Charles H. Chiesa |
|  | &nbsp;&nbsp;Charles H. Chiesa, Treasurer, Chief Accounting |
|  | &nbsp;&nbsp;Officer and Principal Financial Officer |
| &nbsp;&nbsp;Date | &nbsp;&nbsp;August 21, 2025 |

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## Ex-99.Cert

I, Daniel J. Beckman, certify that:

1. I have reviewed this report on Form N-CSR of Columbia Acorn Trust;

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(s) 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:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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(s) 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):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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.

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| | |
|:---|:---|
| Date: August 21, 2025 | &nbsp;&nbsp;/s/ Daniel J. Beckman |
|  | Daniel J. Beckman, President and Principal |
|  | Executive Officer |

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I, Michael G. Clarke, certify that:

1. I have reviewed this report on Form N-CSR of Columbia Acorn Trust;

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(s) 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:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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(s) 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):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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.

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| | | |
|:---|:---|:---|
| Date: August 21, 2025 |  | /s/ Michael G. Clarke |
|  | Michael G. Clarke, Chief Financial Officer, | Michael G. Clarke, Chief Financial Officer, |
|  | Principal Financial Officer and Senior Vice | Principal Financial Officer and Senior Vice |
|  | President | President |

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I, Charles H. Chiesa, certify that:

1. I have reviewed this report on Form N-CSR of Columbia Acorn Trust;

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(s) 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:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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(s) 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):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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.

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| | | |
|:---|:---|:---|
| Date: August 21, 2025 |  | /s/ Charles H. Chiesa |
|  | Charles H. Chiesa, Treasurer, Chief Accounting | Charles H. Chiesa, Treasurer, Chief Accounting |
|  | Officer and Principal Financial Officer | Officer and Principal Financial Officer |

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## Exhibit 99.906

CERTIFICATION PURSUANT TO SECTION 906 OF

THE SARBANES-OXLEY ACT OF 2002

In connection with the Certified Shareholder Report of Columbia Acorn Trust (the "Trust") on Form N- CSR for the period ending June 30, 2025 as filed with the Securities and Exchange Commission on the date hereof ("the Report"), the undersigned hereby certifies that, to his knowledge:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Trust.

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| | |
|:---|:---|
| Date: August 21, 2025 | <u>/s/ Daniel J. Beckman</u> |
|  | Daniel J. Beckman, President and Principal Executive Officer |
| Date: August 21, 2025 | &nbsp;&nbsp;<u>/s/ Michael G. Clarke</u> |
|  | Michael G. Clarke, Chief Financial Officer, |
|  | Principal Financial Officer and Senior Vice President |
| Date: August 21, 2025 | &nbsp;&nbsp;<u>/s/ Charles H. Chiesa</u> |
|  | Charles H. Chiesa, Treasurer, Chief Accounting |
|  | Officer and Principal Financial Officer |

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A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002 has been provided to the Registrant and will be retained by the Registrant and furnished to the Securities and Exchange Commission (the "Commission") or its staff upon request.

This certification is being furnished to the Commission solely pursuant to 18 U.S.C. §1350 and is not being filed as part of the Form N-CSR with the Commission.

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