# EDGAR Filing Document

**Accession Number:** 0000035315
**File Stem:** 0000035315-25-001043
**Filing Date:** 2025-10
**Character Count:** 329898
**Document Hash:** b518ef86bddbf59e853c05cf61df83bd
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000035315-25-001043.hdr.sgml**: 20251023

**ACCESSION NUMBER**: 0000035315-25-001043

**CONFORMED SUBMISSION TYPE**: N-CSRS

**PUBLIC DOCUMENT COUNT**: 56

**CONFORMED PERIOD OF REPORT**: 20250831

**FILED AS OF DATE**: 20251023

**DATE AS OF CHANGE**: 20251023

**EFFECTIVENESS DATE**: 20251023

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** FIDELITY SALEM STREET TRUST
- **CENTRAL INDEX KEY:** 0000035315

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0430

**FILING VALUES:**
- **FORM TYPE:** N-CSRS
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-02105
- **FILM NUMBER:** 251412024

**BUSINESS ADDRESS:**
- **STREET 1:** 245 SUMMER STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210
- **BUSINESS PHONE:** 617-563-7000

**MAIL ADDRESS:**
- **STREET 1:** 245 SUMMER STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FIDELITY FIXED INCOME TRUST
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FIDELITY FLEXIBLE BOND FUND
- **DATE OF NAME CHANGE:** 19860904

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FIDELITY CORPORATE BOND FUND INC
- **DATE OF NAME CHANGE:** 19851225

## Series and Classes Contracts Data

### Fidelity Intermediate Treasury Bond Index Fund (Series ID: S000017677)

| Class ID   | Class Name                                     | Ticker Symbol   |
|:---|:---|:---|
| C000194654 | Fidelity Intermediate Treasury Bond Index Fund | FUAMX           |

### Fidelity Long-Term Treasury Bond Index Fund (Series ID: S000017678)

| Class ID   | Class Name                                  | Ticker Symbol   |
|:---|:---|:---|
| C000194656 | Fidelity Long-Term Treasury Bond Index Fund | FNBGX           |

### Fidelity Short-Term Treasury Bond Index Fund (Series ID: S000017679)

| Class ID   | Class Name                                   | Ticker Symbol   |
|:---|:---|:---|
| C000194658 | Fidelity Short-Term Treasury Bond Index Fund | FUMBX           |

### Fidelity SAI Long-Term Treasury Bond Index Fund (Series ID: S000051138)

| Class ID   | Class Name                                      | Ticker Symbol   |
|:---|:---|:---|
| C000161035 | Fidelity SAI Long-Term Treasury Bond Index Fund | FBLTX           |

### Fidelity SAI U.S. Treasury Bond Index Fund (Series ID: S000052911)

| Class ID   | Class Name                                 | Ticker Symbol   |
|:---|:---|:---|
| C000166451 | Fidelity SAI U.S. Treasury Bond Index Fund | FUTBX           |

### Fidelity Series Long-Term Treasury Bond Index Fund (Series ID: S000054519)

| Class ID   | Class Name                                         | Ticker Symbol   |
|:---|:---|:---|
| C000171137 | Fidelity Series Long-Term Treasury Bond Index Fund | FTLTX           |

### Fidelity SAI Intermediate Treasury Bond Index Fund (Series ID: S000086561)

| Class ID   | Class Name                                         | Ticker Symbol   |
|:---|:---|:---|
| C000252149 | Fidelity SAI Intermediate Treasury Bond Index Fund | FSIWX           |

### Fidelity SAI Short-Term Treasury Bond Index Fund (Series ID: S000086562)

| Class ID   | Class Name                                       | Ticker Symbol   |
|:---|:---|:---|
| C000252150 | Fidelity SAI Short-Term Treasury Bond Index Fund | FSSWX           |

?xml version='1.0' encoding='ASCII'? Prospectus - Investment Objective

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 <u>811-02105</u>

<u>Fidelity Salem Street Trust</u>

(Exact name of registrant as specified in charter)

<u>245 Summer St., Boston, MA 02210</u>

(Address of principal executive offices) &nbsp;&nbsp;&nbsp;&nbsp; (Zip code)

Nicole Macarchuk, Secretary

245 Summer St.

<u>Boston, Massachusetts 02210</u>

(Name and address of agent for service)

Registrant's telephone number, including area code:

<u>617-563-7000</u>

---

| | |
|:---|:---|
| &nbsp;&nbsp;Date of fiscal year end: | &nbsp;&nbsp;February 28 |
| &nbsp;&nbsp;Date of reporting period: | &nbsp;&nbsp;August 31, 2025 |

---

Item 1.

<u>Reports to Stockholders</u>

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® Short-Term Treasury Bond Index Fund<br> **Fidelity® Short-Term Treasury Bond Index Fund : FUMBX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® Short-Term Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® Short-Term Treasury Bond Index Fund  | $2  | 0.03% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $3266390207<br>|
| Number of Holdings | 114<br>|
| Portfolio Turnover | 32%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 0.01 - 0.99% | 12.9 |
| 1 - 1.99% | 17.1 |
| 2 - 2.99% | 8.4 |
| 3 - 3.99% | 25.3 |
| 4 - 4.99% | 34.7 |
| 5 - 5.99% | 0.4 |
| 6 - 6.99% | 0.5 |

---

U.S. Treasury Obligations 99.3 <br> Short-Term Investments and Net Other Assets (Liabilities) 0.7

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img1560_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 99.3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 0.7 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Notes | 98.4<br>|
| US Treasury Bonds | 0.9<br>|
|  | 99.3 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img1560_20250831_1.jpg)<br>| ![](img113934_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9914565.101 3049-TSRS-1025 <br>|

---

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® Series Long-Term Treasury Bond Index Fund<br> **Fidelity® Series Long-Term Treasury Bond Index Fund : FTLTX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® Series Long-Term Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-8544.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® Series Long-Term Treasury Bond Index Fund  | $0 A | 0.00%B |

---

A Amount represents less than $.50

B Amount represents less than 0.005%

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $22092716503<br>|
| Number of Holdings | 94<br>|
| Portfolio Turnover | 10%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 1 - 1.99% | 8.2 |
| 2 - 2.99% | 30.3 |
| 3 - 3.99% | 26.2 |
| 4 - 4.99% | 33.3 |
| 5 - 5.99% | 1.1 |

---

U.S. Treasury Obligations 99.1 <br> Short-Term Investments and Net Other Assets (Liabilities) 0.9

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img2840_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 99.1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 0.9 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Bonds | 98.2<br>|
| US Treasury Notes | 0.9<br>|
|  | 99.1 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img2840_20250831_1.jpg)<br>| ![](img113936_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9914574.101 2840-TSRS-1025 <br>|

---

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® SAI U.S. Treasury Bond Index Fund<br> **Fidelity® SAI U.S. Treasury Bond Index Fund : FUTBX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® SAI U.S. Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® SAI U.S. Treasury Bond Index Fund  | $2  | 0.03% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $8971463746<br>|
| Number of Holdings | 221<br>|
| Portfolio Turnover | 28%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 0.01 - 0.99% | 11.5 |
| 1 - 1.99% | 24.9 |
| 2 - 2.99% | 16.9 |
| 3 - 3.99% | 17.1 |
| 4 - 4.99% | 24.1 |
| 5 - 5.99% | 0.8 |
| 6 - 6.99% | 3.6 |

---

U.S. Treasury Obligations 98.9 <br> Short-Term Investments and Net Other Assets (Liabilities) 1.1

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img2814_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 98.9&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 1.1 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Notes | 75.2<br>|
| US Treasury Bonds | 23.7<br>|
|  | 98.9 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img2814_20250831_1.jpg)<br>| ![](img113937_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9914573.101 2814-TSRS-1025 <br>|

---

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® SAI Long-Term Treasury Bond Index Fund<br> **Fidelity® SAI Long-Term Treasury Bond Index Fund : FBLTX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® SAI Long-Term Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® SAI Long-Term Treasury Bond Index Fund  | $1  | 0.03% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $4209432992<br>|
| Number of Holdings | 45<br>|
| Portfolio Turnover | 35%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 1 - 1.99% | 9.6 |
| 2 - 2.99% | 30.1 |
| 3 - 3.99% | 24.2 |
| 4 - 4.99% | 35.3 |

---

U.S. Treasury Obligations 99.2 <br> Short-Term Investments and Net Other Assets (Liabilities) 0.8

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img2801_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 99.2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 0.8 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Bonds | 99.2<br>|
|  | 99.2 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img2801_20250831_1.jpg)<br>| ![](img113938_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9914572.101 2801-TSRS-1025 <br>|

---

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® Long-Term Treasury Bond Index Fund<br> **Fidelity® Long-Term Treasury Bond Index Fund : FNBGX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® Long-Term Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® Long-Term Treasury Bond Index Fund  | $1  | 0.03% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $5015929002<br>|
| Number of Holdings | 91<br>|
| Portfolio Turnover | 21%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 1 - 1.99% | 13.5 |
| 2 - 2.99% | 19.5 |
| 3 - 3.99% | 30.4 |
| 4 - 4.99% | 34.5 |
| 5 - 5.99% | 1.4 |

---

U.S. Treasury Obligations 99.3 <br> Short-Term Investments and Net Other Assets (Liabilities) 0.7

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img1562_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 99.3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 0.7 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Bonds | 98.6<br>|
| US Treasury Notes | 0.7<br>|
|  | 99.3 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img1562_20250831_1.jpg)<br>| ![](img113941_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9914567.101 3047-TSRS-1025 <br>|

---

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® Intermediate Treasury Bond Index Fund<br> **Fidelity® Intermediate Treasury Bond Index Fund : FUAMX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® Intermediate Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® Intermediate Treasury Bond Index Fund  | $2  | 0.03% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $6824870782<br>|
| Number of Holdings | 45<br>|
| Portfolio Turnover | 45%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 0.01 - 0.99% | 4.5 |
| 1 - 1.99% | 13.5 |
| 2 - 2.99% | 6.8 |
| 3 - 3.99% | 14.4 |
| 4 - 4.99% | 59.9 |
| 6 - 6.99% | 0.2 |

---

U.S. Treasury Obligations 99.3 <br> Short-Term Investments and Net Other Assets (Liabilities) 0.7

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img1561_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 99.3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 0.7 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Notes | 99.1<br>|
| US Treasury Bonds | 0.2<br>|
|  | 99.3 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img1561_20250831_1.jpg)<br>| ![](img113943_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9914566.101 3045-TSRS-1025 <br>|

---

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® SAI Intermediate Treasury Bond Index Fund<br> **Fidelity® SAI Intermediate Treasury Bond Index Fund : FSIWX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® SAI Intermediate Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® SAI Intermediate Treasury Bond Index Fund  | $2  | 0.03% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $3793942607<br>|
| Number of Holdings | 48<br>|
| Portfolio Turnover | 53%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 0.01 - 0.99% | 3.0 |
| 1 - 1.99% | 14.5 |
| 2 - 2.99% | 5.8 |
| 3 - 3.99% | 15.8 |
| 4 - 4.99% | 60.0 |
| 5 - 5.99% | 0.0 |
| 6 - 6.99% | 0.1 |

---

U.S. Treasury Obligations 99.2 <br> Short-Term Investments and Net Other Assets (Liabilities) 0.8

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img7703_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 99.2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 0.8 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Notes | 99.1<br>|
| US Treasury Bonds | 0.1<br>|
|  | 99.2 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img7703_20250831_1.jpg)<br>| ![](img113958_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9916272.100 7703-TSRS-1025 <br>|

---

---

| |
|:---|
| **SEMI-ANNUAL SHAREHOLDER REPORT \|** AS OF AUGUST 31, 2025 |
| Fidelity® SAI Short-Term Treasury Bond Index Fund<br> **Fidelity® SAI Short-Term Treasury Bond Index Fund : FSSWX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® SAI Short-Term Treasury Bond Index Fund for the period March 1, 2025 to August 31, 2025. You can find additional information about the Fund at **fundresearch.fidelity.com/prospectus/sec**. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.

**What were your Fund costs for the last six months?**

(based on hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
|  | **Costs of a $10,000 investment** | **Costs paid as a percentage of a $10,000 investment**  |
| Fidelity® SAI Short-Term Treasury Bond Index Fund  | $2  | 0.03% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $362276603<br>|
| Number of Holdings | 111<br>|
| Portfolio Turnover | 82%<br>|

---

**What did the Fund invest in?** (as of August 31, 2025)

---

| | |
|:---|:---|
| **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** | **COUPON DISTRIBUTION** <br> **(% of Fund's net assets)** |
| 0.01 - 0.99% | 4.6 |
| 1 - 1.99% | 5.7 |
| 2 - 2.99% | 3.1 |
| 3 - 3.99% | 51.0 |
| 4 - 4.99% | 34.0 |
| 5 - 5.99% | 0.1 |
| 6 - 6.99% | 0.3 |

---

U.S. Treasury Obligations 98.8 <br> Short-Term Investments and Net Other Assets (Liabilities) 1.2

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img7700_20250831_AA.jpg) <br>|

---

U.S. Treasury Obligations - 98.8&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br> Short-Term Investments and Net Other Assets (Liabilities) - 1.2 <br>

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| US Treasury Notes | 98.4<br>|
| US Treasury Bonds | 0.4<br>|
|  | 98.8 |

---

---

| | | |
|:---|:---|:---|
| Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. | Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved. |
| ![](img7700_20250831_1.jpg)<br>| ![](img113959_2.jpg) | For additional information about the Fund; including its prospectus, financial information, holdings and proxy information, scan the QR code or visit **fundresearch.fidelity.com/prospectus/sec**<br> 1.9916277.100 7700-TSRS-1025 <br>|

---

Item 2.

<u>Code of Ethics</u>

Not applicable.

Item 3.

<u>Audit Committee Financial Expert</u>

Not applicable.

Item 4.

<u>Principal Accountant Fees and Services</u>

Not applicable.

Item 5.

<u>Audit Committee of Listed Registrants</u>

Not applicable.

Item 6.

<u>Investments</u>

(a) Not applicable.

(b) Not applicable

Item 7.

<u>Financial Statements and Financial Highlights for Open-End Management Investment Companies</u>

**Fidelity® Series Long-Term Treasury Bond Index Fund**

**Semi-Annual Report**

**August 31, 2025**

![](img114162_1.jpg)

![](img114162_2.jpg)

**Contents**

---

| |
|:---|
| **[Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)](#Sec_Item7_XS8-SANN_0)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® Series Long-Term Treasury Bond Index Fund](#Sub_Sec_Fund_2840_XS8-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Notes to Financial Statements](#Sub_Sec_NotestoFinancialStatements2840_XS8-SANN)** |
| **[Item 8: Changes in and Disagreements with Accountants for Open-End Management Investment Companies](#Sec_Item8_XS8-SANN)** |
| **[Item 9: Proxy Disclosures for Open-End Management Investment Companies](#Sec_Item9_XS8-SANN)** |
| **[Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies](#Sec_Item10_XS8-SANN)** |
| **[Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract](#Sec_Item11_XS8-SANN)** |

---

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov.

You may also call 1-800-544-8544 to request a free copy of the proxy voting guidelines.

"BLOOMBERG®" and the Bloomberg indices listed herein (the "Indices") are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL"), the administrator of the Indices (collectively, "Bloomberg") and have been licensed for use for certain purposes by Fidelity. Bloomberg is not affiliated with Fidelity, and Bloomberg does not approve, endorse, review, or recommend the fund. Bloomberg does not guarantee the timeliness, accuracy, or completeness of any data or information relating to the fund.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.© 2025 FMR LLC. All rights reserved.

*This report and the financial statements contained herein are submitted for the general information of the shareholders of the Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.*

*A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. Forms N-PORT are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-PORT may be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.*

*For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.*

**NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE**

*Neither the Fund nor Fidelity Distributors Corporation is a bank.*

**Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)**

**Fidelity® Series Long-Term Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 99.1%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.1%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.1%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.1%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 1.125% 5/15/2040  | 4.69 to 4.88 | 74617000 | 46434508 |
| US Treasury Bonds 1.25% 5/15/2050  | 4.88 | 56000000 | 26387812 |
| US Treasury Bonds 1.375% 11/15/2040  | 2.02 to 3.49 | 399563000 | 254643374 |
| US Treasury Bonds 1.375% 8/15/2050  | 4.97 to 5.03 | 105500000 | 50969688 |
| US Treasury Bonds 1.625% 11/15/2050  | 4.92 to 5.04 | 523600000 | 270144875 |
| US Treasury Bonds 1.75% 8/15/2041  | 1.97 to 4.77 | 296740000 | 196567069 |
| US Treasury Bonds 1.875% 11/15/2051  | 3.11 to 4.80 | 353820000 | 192555478 |
| US Treasury Bonds 1.875% 2/15/2041  | 1.92 to 4.40 | 633606000 | 435430872 |
| US Treasury Bonds 1.875% 2/15/2051  | 2.12 to 4.79 | 611705000 | 336509436 |
| US Treasury Bonds 2% 11/15/2041  | 1.83 to 4.09 | 915080000 | 627437468 |
| US Treasury Bonds 2% 2/15/2050  | 1.64 to 4.99 | 435249000 | 251254284 |
| US Treasury Bonds 2% 8/15/2051  | 1.90 to 4.92 | 835220000 | 471377288 |
| US Treasury Bonds 2.25% 2/15/2052  | 2.17 to 5.04 | 1428240000 | 853763938 |
| US Treasury Bonds 2.25% 5/15/2041  | 1.83 to 4.45 | 831582000 | 602604599 |
| US Treasury Bonds 2.25% 8/15/2046  | 3.02 to 5.04 | 185341000 | 120080695 |
| US Treasury Bonds 2.25% 8/15/2049  | 2.55 to 4.83 | 240147000 | 148196966 |
| US Treasury Bonds 2.375% 11/15/2049  | 4.26 to 4.94 | 361492000 | 228784896 |
| US Treasury Bonds 2.375% 2/15/2042  | 2.60 to 3.32 | 864460000 | 625140560 |
| US Treasury Bonds 2.375% 5/15/2051  | 1.90 to 5.08 | 651374000 | 404742432 |
| US Treasury Bonds 2.5% 2/15/2045  | 2.99 to 4.23 | 686749000 | 478470905 |
| US Treasury Bonds 2.5% 2/15/2046  | 3.02 to 4.87 | 186618000 | 127971836 |
| US Treasury Bonds 2.5% 5/15/2046  | 3.02 to 3.43 | 136970000 | 93642537 |
| US Treasury Bonds 2.75% 11/15/2042  | 1.48 to 4.32 | 193274000 | 146080415 |
| US Treasury Bonds 2.75% 11/15/2047  | 3.06 to 4.90 | 267357000 | 187745186 |
| US Treasury Bonds 2.75% 8/15/2042  | 3.01 to 4.15 | 252260000 | 191638769 |
| US Treasury Bonds 2.75% 8/15/2047  | 2.39 to 3.20 | 458264000 | 322771805 |
| US Treasury Bonds 2.875% 11/15/2046  | 3.06 to 4.65 | 11125000 | 8100390 |
| US Treasury Bonds 2.875% 5/15/2043  | 2.31 to 4.03 | 241482000 | 184677131 |
| US Treasury Bonds 2.875% 5/15/2049  | 1.40 to 4.92 | 596099000 | 421530478 |
| US Treasury Bonds 2.875% 5/15/2052  | 3.02 to 4.96 | 269780000 | 186032278 |
| US Treasury Bonds 2.875% 8/15/2045  | 3.36 to 4.04 | 18732000 | 13852167 |
| US Treasury Bonds 3% 11/15/2044  | 2.99 to 3.82 | 172537000 | 131633600 |
| US Treasury Bonds 3% 11/15/2045  | 1.74 to 4.48 | 381862000 | 287947814 |
| US Treasury Bonds 3% 2/15/2047  | 1.89 to 3.13 | 489794000 | 363825106 |
| US Treasury Bonds 3% 2/15/2048  | 1.43 to 3.88 | 595209000 | 436618353 |
| US Treasury Bonds 3% 2/15/2049  | 4.13 to 4.90 | 376287000 | 273322531 |
| US Treasury Bonds 3% 5/15/2042  | 3.14 to 4.13 | 79079000 | 62725710 |
| US Treasury Bonds 3% 5/15/2045  | 2.33 to 4.02 | 158044000 | 119817108 |
| US Treasury Bonds 3% 5/15/2047  | 1.92 to 4.50 | 234862000 | 173917145 |
| US Treasury Bonds 3% 8/15/2048  | 2.39 to 4.52 | 203982000 | 148859051 |
| US Treasury Bonds 3% 8/15/2052  | 3.29 to 5.04 | 470480000 | 332717575 |
| US Treasury Bonds 3.125% 11/15/2041  | 1.92 to 3.03 | 59163000 | 48229400 |
| US Treasury Bonds 3.125% 2/15/2042  | 2.65 to 3.99 | 154840000 | 125583708 |
| US Treasury Bonds 3.125% 2/15/2043  | 3.01 to 5.01 | 140221000 | 111831725 |
| US Treasury Bonds 3.125% 5/15/2048  | 1.51 to 4.93 | 273142000 | 204525741 |
| US Treasury Bonds 3.125% 8/15/2044  | 1.96 to 4.20 | 77966000 | 60929211 |
| US Treasury Bonds 3.25% 5/15/2042  | 3.27 to 4.64 | 329100000 | 270620473 |
| US Treasury Bonds 3.375% 11/15/2048  | 3.70 to 5.19 | 310991000 | 242682312 |
| US Treasury Bonds 3.375% 5/15/2044  | 2.95 to 3.01 | 122930000 | 100163941 |
| US Treasury Bonds 3.375% 8/15/2042  | 4.41 to 5.15 | 262860000 | 219241669 |
| US Treasury Bonds 3.5% 2/15/2039  | 3.03 to 3.84 | 78034000 | 70361673 |
| US Treasury Bonds 3.625% 2/15/2044  | 1.64 to 3.82 | 142857000 | 121171753 |
| US Treasury Bonds 3.625% 2/15/2053  | 3.67 to 5.08 | 342780000 | 274371289 |
| US Treasury Bonds 3.625% 5/15/2053  | 3.84 to 4.00 | 741700000 | 593041299 |
| US Treasury Bonds 3.625% 8/15/2043  | 1.23 to 5.02 | 393132000 | 335298595 |
| US Treasury Bonds 3.75% 11/15/2043  | 3.04 to 4.82 | 103069000 | 89239234 |
| US Treasury Bonds 3.75% 8/15/2041  | 2.19 to 4.60 | 107358000 | 95682818 |
| US Treasury Bonds 3.875% 2/15/2043  | 4.71 to 4.92 | 184400000 | 163849485 |
| US Treasury Bonds 3.875% 5/15/2043  | 4.73 to 5.28 | 236000000 | 209095080 |
| US Treasury Bonds 3.875% 8/15/2040  | 4.78 | 189600000 | 173669156 |
| US Treasury Bonds 4% 11/15/2042  | 3.96 to 5.22 | 251320000 | 227670396 |
| US Treasury Bonds 4% 11/15/2052  | 3.60 to 4.81 | 387400000 | 332467889 |
| US Treasury Bonds 4.125% 8/15/2044  | 4.60 to 4.80 | 92400000 | 83936016 |
| US Treasury Bonds 4.125% 8/15/2053  | 4.70 to 5.07 | 482900000 | 422933628 |
| US Treasury Bonds 4.25% 11/15/2040  | 2.93 to 3.12 | 47867000 | 45671848 |
| US Treasury Bonds 4.25% 2/15/2054  | 4.37 to 4.99 | 233000000 | 208462188 |
| US Treasury Bonds 4.25% 5/15/2039  | 3.03 to 4.73 | 13257000 | 12874307 |
| US Treasury Bonds 4.25% 8/15/2054  | 4.13 to 4.72 | 522300000 | 467295281 |
| US Treasury Bonds 4.375% 11/15/2039  | 4.63 to 4.83 | 146400000 | 143008782 |
| US Treasury Bonds 4.375% 2/15/2038  | 2.35 to 4.41 | 57424000 | 57275954 |
| US Treasury Bonds 4.375% 5/15/2040  | 4.06 to 4.75 | 114924900 | 111818336 |
| US Treasury Bonds 4.375% 5/15/2041  | 2.99 to 4.79 | 104568000 | 100806003 |
| US Treasury Bonds 4.375% 8/15/2043  | 4.39 to 4.72 | 88670000 | 83841642 |
| US Treasury Bonds 4.5% 11/15/2054  | 4.37 to 4.80 | 604100000 | 563913190 |
| US Treasury Bonds 4.5% 2/15/2036  | 1.69 to 4.51 | 97818000 | 100324586 |
| US Treasury Bonds 4.5% 2/15/2044  | 4.74 to 4.92 | 450900000 | 432194693 |
| US Treasury Bonds 4.5% 5/15/2038  | 3.97 to 4.79 | 62700000 | 63346594 |
| US Treasury Bonds 4.5% 8/15/2039  | 4.14 | 48244000 | 47901015 |
| US Treasury Bonds 4.625% 11/15/2044  | 4.47 to 4.86 | 219100000 | 212544116 |
| US Treasury Bonds 4.625% 2/15/2040  | 4.62 to 4.85 | 30743000 | 30793437 |
| US Treasury Bonds 4.625% 2/15/2055  | 4.47 to 4.92 | 668900000 | 637545313 |
| US Treasury Bonds 4.625% 5/15/2044  | 4.74 to 4.75 | 341000000 | 331702424 |
| US Treasury Bonds 4.625% 5/15/2054  | 4.34 to 4.80 | 473400000 | 451005960 |
| US Treasury Bonds 4.75% 11/15/2043  | 4.52 to 4.90 | 383000000 | 379454259 |
| US Treasury Bonds 4.75% 11/15/2053  | 4.21 to 4.82 | 757200000 | 736081223 |
| US Treasury Bonds 4.75% 2/15/2037  | 2.93 to 2.95 | 28863000 | 30032176 |
| US Treasury Bonds 4.75% 2/15/2041  | 3.79 to 4.87 | 235771100 | 237668322 |
| US Treasury Bonds 4.75% 5/15/2055  | 4.79 to 4.89 | 364300000 | 354395594 |
| US Treasury Bonds 4.75% 8/15/2045  | 4.74 | 37700000 | 37741233 |
| US Treasury Bonds 4.75% 8/15/2055  | 4.92 | 167500000 | 162998438 |
| US Treasury Bonds 5% 5/15/2037  | 1.70 to 4.41 | 136927000 | 145484938 |
| US Treasury Bonds 5% 5/15/2045  | 4.79 to 4.89 | 90000000 | 91504688 |
| US Treasury Notes 4.75% 2/15/2045  | 4.71 to 4.94 | 213400000 | 210232343 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $26,649,020,110) |  |  | **21901439502** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 1.3%** | &nbsp;&nbsp;**Money Market Funds - 1.3%** | &nbsp;&nbsp;**Money Market Funds - 1.3%** | &nbsp;&nbsp;**Money Market Funds - 1.3%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $286,045,696)<br>| 4.36 | 285988498 | **286045696** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 100.4%**<br> (Cost $26,935,065,806)<br>| <br>**22187485198** |
| **NET OTHER ASSETS (LIABILITIES) - (0.4)%**  | **(94768695)** |
| **NET ASSETS - 100.0%** | **22092716503** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 253067874 | 872353228 | 839375406 | 1948495 | - | - | 286045696 | 285988498 | 0.5% |
| Fidelity Securities Lending Cash Central Fund | 222273265 | 127276450 | 349549715 | 7881 | - | - | - | - | 0.0% |
| Total | 475341139 | 999629678 | 1188925121 | 1956376 | - | - | 286045696 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts in the dividend income column for Fidelity Securities Lending Cash Central Fund represents the income earned on investing cash collateral, less rebates paid to borrowers and any lending agent fees associated with the loan, plus any premium income received for lending certain types of securities.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 21901439502 | - | 21901439502 | - |
|  **Money Market Funds** | 286045696 | 286045696 | - | - |
| **Total Investments in Securities:** | 22187485198 | 286045696 | 21901439502 | - |

---

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $26,649,020,110) | $21901439502 |  |
| Fidelity Central Funds (cost $286,045,696) | 286045696 |  |
| Total Investment in Securities (cost $26,935,065,806) |  | $22187485198 |
| Receivable for investments sold |  | 126968125 |
| Receivable for fund shares sold |  | 131358886 |
| Interest receivable |  | 152678803 |
| Distributions receivable from Fidelity Central Funds |  | 582390 |
| **Total assets** |  | 22599073402 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $200771734 |  |
| Payable for fund shares redeemed | 305542026 |  |
| Distributions payable | 3665 |  |
| Other payables and accrued expenses | 39474 |  |
| **Total liabilities** |  | 506356899 |
| **Net Assets**  |  | $22092716503 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $29187929867 |
| Total accumulated earnings (loss) |  | (7095213364) |
| **Net Assets** |  | $22092716503 |
| **Net Asset Value**, offering price and redemption price per share ($22,092,716,503 ÷ 4,157,118,756 shares) |  | $5.31 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $439704368 |
| Income from Fidelity Central Funds (including $7,881 from security lending)  |  | 1956376 |
| **Total income** |  | 441660744 |
| **Expenses** |  |  |
| Custodian fees and expenses | $74886 |  |
| Independent trustees' fees and expenses | 23928 |  |
| Total expenses before reductions | 98814 |  |
| Expense reductions | (22) |  |
| Total expenses after reductions |  | 98792 |
| **Net Investment income (loss)** |  | 441561952 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (384712869) |  |
| Total net realized gain (loss) |  | (384712869) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | (648443640) |
| **Net gain (loss)** |  | (1033156509) |
| **Net increase (decrease) in net assets resulting from operations** |  | $(591594557) |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **Year ended**<br> **February 28, 2025** |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $441561952 | $729606577 |
| &nbsp;&nbsp;Net realized gain (loss) | (384712869)<br>| (913871107)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | (648443640) | 950687866<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | (591594557)<br>| 766423336<br>|
| Distributions to shareholders | (408346129)<br>| (676666979)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 3182844602 | 5495827183 |
| Reinvestment of distributions | 408346128<br>| 676584575<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (1541838023) | (4982406014) |
| **Net increase (decrease) in net assets resulting from share transactions** | 2049352707<br>| 1190005744<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 1049412021<br>| 1279762101<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 21043304482 | 19763542381<br>|
| &nbsp;&nbsp;End of period | $22092716503 | $21043304482 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 598776356 | 1006501340 |
| Issued in reinvestment of distributions | 76053029<br>| 122142333<br>|
| &nbsp;&nbsp;Redeemed | (286577023) | (895144557) |
| &nbsp;&nbsp;Net increase (decrease) | 388252362 | 233499116 |

---

**Financial Highlights** 

**Fidelity® Series Long-Term Treasury Bond Index Fund** <br>

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025**  | **2024** A  | **2023**  | **2022**  | **2021**  |
| **Selected Per-Share Data**  |  |  |  |  |  |  |
| Net asset value, beginning of period  | $5.58 | $5.59 | $5.94 | $8.05 | $8.33 | $10.06 |
| Income from Investment Operations  |  |  |  |  |  |  |
| Net investment income (loss) B,C | .112  | .213  | .202  | .185  | .175  | .201  |
| Net realized and unrealized gain (loss)  | (.278)  | (.026) D | (.365)  | (2.121)  | (.253)  | (.752)  |
| Total from investment operations  | (.166)  | .187  | (.163)  | (1.936)  | (.078)  | (.551)  |
| Distributions from net investment income  | (.104)  | (.197)  | (.187)  | (.174)  | (.169)  | (.199)  |
| Distributions from net realized gain  | -  | -  | -  | -  | (.033)  | (.980)  |
| Total distributions  | (.104)  | (.197)  | (.187)  | (.174)  | (.202)  | (1.179)  |
| Net asset value, end of period  | $5.31 | $5.58 | $5.59 | $5.94 | $8.05 | $8.33 |
| **Total Return** E,F | (2.98)% <br>| 3.44%  | (2.77)%  | (24.16)%  | (1.01)%  | (6.47)%  |
| **Ratios to Average Net Assets** C,G,H |  |  |  |  |  |  |
| Expenses before reductions I | -% J | -%  | -%  | -%  | -%  | -%  |
| Expenses net of fee waivers, if any I | -% J<br>| -%  | -%  | -%  | -%  | -%  |
| Expenses net of all reductions, if any I | -% J | -%  | -%  | -%  | -%  | -%  |
| Net investment income (loss)  | 4.17% J | 3.84%  | 3.53%  | 2.87%  | 2.10%  | 2.03%  |
| **Supplemental Data** |  |  |  |  |  |  |
| Net assets, end of period (000 omitted) | $22092717 | $21043304 | $19763542 | $17545738 | $15129018 | $9356431 |
| Portfolio turnover rate K | 10% J<br>| 18%  | 11%  | 10%  | 18%  | 56%  |

---

A*For the year ended February 29.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*The amount shown for a share outstanding does not correspond with the aggregate net gain (loss) on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating market values of the investments of the Fund.*

E*Total returns for periods of less than one year are not annualized.*

F*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

G*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

H*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

I*Amount represents less than .005%.*

J*Annualized.*

K*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

**Notes to Financial Statements** **(Unaudited)**

For the period ended August 31, 2025

**1. Organization.**

Fidelity Series Long-Term Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered only to certain other Fidelity funds, Fidelity managed 529 plans, and Fidelity managed collective investment trusts. 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.

**2. Investments in Fidelity Central Funds.**

Funds may invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Schedule of Investments lists any Fidelity Central Funds held as an investment as of period end, but does not include the underlying holdings of each Fidelity Central Fund. An investing fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

Based on its investment objective, each Fidelity Central Fund may invest or participate in various investment vehicles or strategies that are similar to those of the investing fund. These strategies are consistent with the investment objectives of the investing fund and may involve certain economic risks which may cause a decline in value of each of the Fidelity Central Funds and thus a decline in the value of the investing fund.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fidelity Central Fund** | **Investment Manager** | **Investment Objective** | **Investment Practices** | **Expense RatioA** |
| Fidelity Money Market Central Funds | Fidelity Management & Research Company LLC (FMR) | Each fund seeks to obtain a high level of current income consistent with the preservation of capital and liquidity. | Short-term Investments | Less than .005% |

---

*A Expenses expressed as a percentage of average net assets and are as of each underlying Central Fund's most recent annual or semi-annual shareholder report.* 

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds which contain the significant accounting policies (including investment valuation policies) of those funds, and are not covered by the Report of Independent Registered Public Accounting Firm, are available on the Securities and Exchange Commission website or upon request.

**3. Significant Accounting Policies.**

The Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 *Financial Services - Investment Companies*. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. The Fund operates as a single operating segment. The Fund's income, expenses, assets, and performance are regularly monitored and assessed as a whole by the investment adviser and other individuals responsible for oversight functions of the Trust, using the information presented in the financial statements and financial highlights. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The Fund's Schedule of Investments lists any underlying mutual funds or exchange-traded funds but does not include the underlying holdings of these funds. The following summarizes the significant accounting policies of the Fund:

**Investment Valuation.** Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has designated the Fund's investment adviser as the valuation designee responsible for the fair valuation function and performing fair value determinations as needed. The investment adviser has established a Fair Value Committee (the Committee) to carry out the day-to-day fair valuation responsibilities and has adopted policies and procedures to govern the fair valuation process and the activities of the Committee. In accordance with these fair valuation policies and procedures, which have been approved by the Board, the Fund attempts to obtain prices from one or more third party pricing services or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with the policies and procedures. Factors used in determining fair value vary by investment type and may include market or investment specific events, transaction data, estimated cash flows, and market observations of comparable investments. The frequency that the fair valuation procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee manages the Fund's fair valuation practices and maintains the fair valuation policies and procedures. The Fund's investment adviser reports to the Board information regarding the fair valuation process and related material matters.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing services or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing services who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing services. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of August 31, 2025 is included at the end of the Fund's Schedule of Investments.

**Investment Transactions and Income.** For financial reporting purposes, the Fund's investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

**Expenses.** Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

**Income Tax Information and Distributions to Shareholders.** Each year, the Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. The Fund files a U.S. federal tax return, in addition to state and local tax returns as required. The Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

---

| | |
|:---|:---|
| **Gross unrealized appreciation** | $35650395 |
| **Gross unrealized depreciation** | <u>(4709293044)</u> |
| **Net unrealized appreciation (depreciation)** | <u>$(4673642649)</u> |
| **Tax cost** | <u>$26861127847</u> |

---

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of prior fiscal period end and is subject to adjustment.

---

| | |
|:---|:---|
| Short-term | $(188109629) |
| Long-term | <u>(1853727588)</u> |
| **Total capital loss carryforward** | <u>$(2041837217)</u> |

---

**New Accounting Pronouncement.** 

In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures. Effective for annual periods beginning after December 15, 2024, the amendments require greater disaggregation of disclosures related to income taxes paid. The ASU allows for early adoption and amendments should be applied on a prospective basis. Management is currently evaluating the impact of the ASU but does not expect this guidance to materially impact the financial statements.

**4. Fees and Other Transactions with Affiliates.**

**Management Fee.** Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund does not pay a management fee. Under the management contract, the investment adviser or an affiliate pays all ordinary operating expenses of the Fund, except custody fees, fees and expenses of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses.

**Interfund Trades.** Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board of Trustees. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Any interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note. During the period, there were no interfund trades.

**5. Committed Line of Credit.**

Certain Funds participate with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes.

Commitment fees are charged based on the unused amount of the line of credit at an annual rate of .10%, and then allocated to each participating fund based on its pro-rata portion of the line of credit. The commitment fees are borne by the investment adviser.

Interest is charged to a participating fund based on its borrowings at an annual rate of .75% plus the highest of (i) daily SOFR plus a .10% spread adjustment, (ii) Federal Funds Effective Rate, or (iii) Overnight Bank Funding Rate. During the period, there were no borrowings on this line of credit.

The line of credit agreement will expire in March 2026 unless extended or renewed.

**6. Security Lending.** 

Funds lend portfolio securities from time to time in order to earn additional income. Lending agents are used, including National Financial Services (NFS), an affiliate of the investment adviser. Pursuant to a securities lending agreement, NFS will receive a fee, which is capped at 9.9% of a fund's daily lending revenue, for its services as lending agent. A fund may lend securities to certain qualified borrowers, including NFS. On the settlement date of the loan, the borrowers provide collateral (in the form of U.S. Treasury obligations, letters of credit and/or cash) against the loaned securities and maintains collateral in an amount not less than 100% of the fair value of the loaned securities during the period of the loan. The fair value of the loaned securities is determined at the close of business of a fund and any additional required collateral is delivered to a fund on the next business day. A fund or borrower may terminate the loan at any time, and if the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund may apply collateral received from the borrower against the obligation. A fund may experience delays and costs in recovering the securities loaned or gaining access to non-cash collateral. Any cash collateral received is invested in the Fidelity Securities Lending Cash Central Fund. Any loaned securities are identified as such in the Schedule of Investments, and the value of loaned securities and cash collateral at period end, as applicable, are presented in the Statement of Assets and Liabilities. Security lending income represents the income earned on investing cash collateral less rebates paid to borrowers, plus any premium income received, or for non-cash collateral, fees received from borrowers as compensation for the securities loaned. Securities lending income is reduced by any lending agent fees associated with the loan. Any security lending income earned on investing cash collateral is presented in the Statement of Operations as a component of income from Fidelity Central Funds. Any security lending income earned on non-cash collateral is presented in the Statement of Operations as a component of interest. Affiliated security lending activity, if any, was as follows:

---

| | | | |
|:---|:---|:---|:---|
|  | **Total Security Lending Fees Paid to NFS ($)** | **Security Lending Income From Securities Loaned to NFS ($)** | **Value of Securities Loaned to NFS at Period End ($)** |
| **Fidelity Series Long-Term Treasury Bond Index Fund** | 837 | - | - |

---

**7. Expense Reductions.** 

Through arrangements with the Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses by $22.

**8. Other.**

A fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the fund. In the normal course of business, a fund may also enter into contracts that provide general indemnifications. A fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against a fund. The risk of material loss from such claims is considered remote.

At the end of the period, mutual funds and accounts managed by the investment adviser or its affiliates were the owners of record of all of the outstanding shares of the Fund.

**9. Risk and Uncertainties.**

Many factors affect a fund's performance. Developments that disrupt global economies and financial markets, such as public health emergencies, military conflicts, terrorism, government restrictions, political changes, and environmental disasters, may significantly affect a fund's investment performance. The effects of these developments to a fund will be impacted by the types of securities in which a fund invests, the financial condition, industry, economic sector, and geographic location of an issuer, and a fund's level of investment in the securities of that issuer. Significant concentrations in security types, issuers, industries, sectors, and geographic locations may magnify the factors that affect a fund's performance.

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

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 9: Proxy Disclosures for Open-End Management Investment Companies**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies**

**(Unaudited)**

Note: This information is disclosed as part of the financial statements for each Fund as part of Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies.

**Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

![](img114162_4.jpg)<br>

1.9872675.109 XS8-SANN-1025

**Fidelity® SAI U.S. Treasury Bond Index Fund**

**Semi-Annual Report**

**August 31, 2025**

Offered exclusively to certain clients of the Adviser, or its affiliates, including Strategic Advisers LLC (Strategic Advisers) - not available for sale to the general public. Fidelity® SAI is a product name of Fidelity® funds dedicated to certain programs affiliated with Strategic Advisers.

![](img114163_1.jpg)

![](img114163_2.jpg)

**Contents**

---

| |
|:---|
| **[Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)](#Sec_Item7_UYB-SANN_0)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® SAI U.S. Treasury Bond Index Fund](#Sub_Sec_Fund_2814_UYB-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Notes to Financial Statements](#Sub_Sec_NotestoFinancialStatements2814_UYB-SANN)** |
| **[Item 8: Changes in and Disagreements with Accountants for Open-End Management Investment Companies](#Sec_Item8_UYB-SANN)** |
| **[Item 9: Proxy Disclosures for Open-End Management Investment Companies](#Sec_Item9_UYB-SANN)** |
| **[Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies](#Sec_Item10_UYB-SANN)** |
| **[Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract](#Sec_Item11_UYB-SANN)** |

---

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov.

You may also call 1-800-544-3455 to request a free copy of the proxy voting guidelines.

"BLOOMBERG®" and the Bloomberg indices listed herein (the "Indices") are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL"), the administrator of the Indices (collectively, "Bloomberg") and have been licensed for use for certain purposes by Fidelity. Bloomberg is not affiliated with Fidelity, and Bloomberg does not approve, endorse, review, or recommend the fund. Bloomberg does not guarantee the timeliness, accuracy, or completeness of any data or information relating to the fund.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.© 2025 FMR LLC. All rights reserved.

*This report and the financial statements contained herein are submitted for the general information of the shareholders of the Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.*

*A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. Forms N-PORT are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-PORT may be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.*

*For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.*

**NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE**

*Neither the Fund nor Fidelity Distributors Corporation is a bank.*

**Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)**

**Fidelity® SAI U.S. Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 98.9%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 98.9%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 98.9%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 98.9%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 1.125% 5/15/2040  | 3.41 to 3.46 | 15484000 | 9635766 |
| US Treasury Bonds 1.125% 8/15/2040  | 2.16 to 3.74 | 22637000 | 13935903 |
| US Treasury Bonds 1.25% 5/15/2050  | 3.79 | 72000 | 33927 |
| US Treasury Bonds 1.375% 11/15/2040  | 2.06 to 2.31 | 43434300 | 27680883 |
| US Treasury Bonds 1.375% 8/15/2050  | 4.03 | 4170000 | 2014631 |
| US Treasury Bonds 1.625% 11/15/2050  | 4.41 to 4.70 | 62237500 | 32110660 |
| US Treasury Bonds 1.75% 8/15/2041  | 2.05 to 3.46 | 89327000 | 59172159 |
| US Treasury Bonds 1.875% 11/15/2051  | 2.50 to 4.41 | 83063000 | 45204442 |
| US Treasury Bonds 1.875% 2/15/2041  | 2.27 | 14329000 | 9847269 |
| US Treasury Bonds 1.875% 2/15/2051  | 2.30 to 4.40 | 110431000 | 60749991 |
| US Treasury Bonds 2% 11/15/2041  | 2.14 to 3.45 | 83700000 | 57390082 |
| US Treasury Bonds 2% 2/15/2050  | 3.51 to 3.79 | 30778000 | 17767081 |
| US Treasury Bonds 2% 8/15/2051  | 3.23 to 4.83 | 76045000 | 42917897 |
| US Treasury Bonds 2.25% 2/15/2052  | 3.02 to 3.93 | 56800000 | 33953531 |
| US Treasury Bonds 2.25% 5/15/2041  | 2.18 to 3.39 | 67333000 | 48792753 |
| US Treasury Bonds 2.25% 8/15/2046  | 3.41 | 1600000 | 1036625 |
| US Treasury Bonds 2.25% 8/15/2049  | 3.53 | 80000 | 49369 |
| US Treasury Bonds 2.375% 2/15/2042  | 3.24 | 32900000 | 23791875 |
| US Treasury Bonds 2.375% 5/15/2051  | 3.98 to 4.54 | 100837000 | 62656803 |
| US Treasury Bonds 2.5% 2/15/2045  | 4.15 | 2401000 | 1672822 |
| US Treasury Bonds 2.5% 2/15/2046  | 3.09 to 4.13 | 15623000 | 10713350 |
| US Treasury Bonds 2.5% 5/15/2046  | 2.98 to 4.81 | 24683000 | 16875073 |
| US Treasury Bonds 2.75% 11/15/2042  | 4.05 | 13826000 | 10449972 |
| US Treasury Bonds 2.75% 11/15/2047  | 3.09 | 318000 | 223308 |
| US Treasury Bonds 2.75% 8/15/2042  | 3.26 to 4.84 | 59738000 | 45382212 |
| US Treasury Bonds 2.75% 8/15/2047  | 3.10 to 3.25 | 5231000 | 3684381 |
| US Treasury Bonds 2.875% 11/15/2046  | 3.05 to 4.61 | 5289000 | 3851053 |
| US Treasury Bonds 2.875% 5/15/2043  | 3.02 to 4.08 | 50784000 | 38837857 |
| US Treasury Bonds 2.875% 5/15/2049  | 4.62 | 11000 | 7779 |
| US Treasury Bonds 2.875% 5/15/2052  | 3.20 to 4.87 | 12400000 | 8550672 |
| US Treasury Bonds 2.875% 8/15/2045  | 1.43 to 4.94 | 58254000 | 43078378 |
| US Treasury Bonds 3% 11/15/2044  | 4.13 to 4.76 | 63400000 | 48369742 |
| US Treasury Bonds 3% 11/15/2045  | 3.71 to 3.99 | 57800000 | 43584813 |
| US Treasury Bonds 3% 2/15/2047  | 1.70 to 3.41 | 53589000 | 39806579 |
| US Treasury Bonds 3% 2/15/2048  | 3.07 to 4.97 | 7159000 | 5251518 |
| US Treasury Bonds 3% 2/15/2049  | 4.59 | 13911000 | 10104494 |
| US Treasury Bonds 3% 5/15/2042  | 3.25 to 4.92 | 14138000 | 11214306 |
| US Treasury Bonds 3% 5/15/2045  | 2.40 to 3.83 | 39700000 | 30097563 |
| US Treasury Bonds 3% 5/15/2047  | 3.38 to 3.41 | 69492000 | 51459369 |
| US Treasury Bonds 3% 8/15/2048  | 3.80 to 4.55 | 13608000 | 9930651 |
| US Treasury Bonds 3% 8/15/2052  | 3.02 to 4.67 | 100400000 | 71001625 |
| US Treasury Bonds 3.125% 11/15/2041  | 3.41 to 4.15 | 50864000 | 41464094 |
| US Treasury Bonds 3.125% 2/15/2042  | 3.99 to 4.49 | 12800000 | 10381500 |
| US Treasury Bonds 3.125% 2/15/2043  | 4.54 | 27201000 | 21693860 |
| US Treasury Bonds 3.125% 5/15/2048  | 4.05 | 4500 | 3370 |
| US Treasury Bonds 3.375% 11/15/2048  | 3.13 | 1791300 | 1397844 |
| US Treasury Bonds 3.375% 5/15/2044  | 3.50 to 4.46 | 61800000 | 50354930 |
| US Treasury Bonds 3.375% 8/15/2042  | 4.93 | 10700000 | 8924469 |
| US Treasury Bonds 3.5% 2/15/2039  | 2.66 | 315000 | 284029 |
| US Treasury Bonds 3.625% 2/15/2044  | 3.85 to 4.56 | 10956000 | 9292913 |
| US Treasury Bonds 3.625% 2/15/2053  | 3.66 to 4.71 | 59000000 | 47225352 |
| US Treasury Bonds 3.625% 5/15/2053  | 4.25 to 4.54 | 13900000 | 11114027 |
| US Treasury Bonds 3.625% 8/15/2043  | 3.59 to 4.55 | 42601000 | 36333993 |
| US Treasury Bonds 3.875% 5/15/2043  | 4.78 | 8400000 | 7442367 |
| US Treasury Bonds 4% 11/15/2052  | 4.40 | 41900000 | 35958711 |
| US Treasury Bonds 4.125% 8/15/2053  | 4.20 to 5.07 | 91100000 | 79787230 |
| US Treasury Bonds 4.25% 11/15/2040  | 3.71 | 80000 | 76331 |
| US Treasury Bonds 4.25% 2/15/2054  | 4.44 to 4.51 | 43600000 | 39008375 |
| US Treasury Bonds 4.25% 5/15/2039  | 3.45 to 3.99 | 1598000 | 1551870 |
| US Treasury Bonds 4.375% 11/15/2039  | 4.37 | 340000 | 332124 |
| US Treasury Bonds 4.375% 2/15/2038  | 2.80 to 3.16 | 6284000 | 6267799 |
| US Treasury Bonds 4.375% 5/15/2041  | 3.28 to 3.79 | 7517000 | 7246564 |
| US Treasury Bonds 4.5% 11/15/2054  | 4.37 to 4.80 | 31000000 | 28937773 |
| US Treasury Bonds 4.5% 2/15/2036  | 2.61 to 3.34 | 24732200 | 25365963 |
| US Treasury Bonds 4.5% 2/15/2044  | 4.68 | 10900000 | 10447820 |
| US Treasury Bonds 4.5% 5/15/2038  | 4.16 | 24300000 | 24550594 |
| US Treasury Bonds 4.5% 8/15/2039  | 4.39 | 14731000 | 14626272 |
| US Treasury Bonds 4.625% 2/15/2040  | 2.99 | 5000 | 5008 |
| US Treasury Bonds 4.625% 2/15/2055  | 4.58 to 4.92 | 50900000 | 48514063 |
| US Treasury Bonds 4.625% 5/15/2054  | 4.54 to 4.63 | 22100000 | 21054566 |
| US Treasury Bonds 4.75% 11/15/2053  | 4.00 to 4.48 | 37400000 | 36356891 |
| US Treasury Bonds 4.75% 2/15/2037  | 2.32 to 2.78 | 13000 | 13527 |
| US Treasury Bonds 4.75% 2/15/2041  | 4.03 | 11100000 | 11189320 |
| US Treasury Bonds 4.75% 5/15/2055  | 4.79 to 4.89 | 30700000 | 29865344 |
| US Treasury Bonds 4.75% 8/15/2045  | 4.74 | 8000000 | 8008750 |
| US Treasury Bonds 4.75% 8/15/2055  | 4.91 to 4.92 | 19900000 | 19365188 |
| US Treasury Bonds 5% 5/15/2037  | 2.90 to 4.31 | 4967000 | 5277438 |
| US Treasury Bonds 5% 5/15/2045  | 4.85 to 4.92 | 13500000 | 13725703 |
| US Treasury Bonds 5.25% 11/15/2028  | 2.65 to 2.98 | 31601000 | 33151424 |
| US Treasury Bonds 5.25% 2/15/2029  | 2.75 to 3.84 | 10374000 | 10951864 |
| US Treasury Bonds 6.125% 11/15/2027  | 2.86 to 2.94 | 139604000 | 147080450 |
| US Treasury Bonds 6.25% 5/15/2030  | 3.95 to 4.21 | 116378000 | 129134120 |
| US Treasury Bonds 6.375% 8/15/2027  | 3.09 to 3.25 | 21500000 | 22618672 |
| US Treasury Bonds 6.5% 11/15/2026  | 3.02 | 39000 | 40365 |
| US Treasury Bonds 6.625% 2/15/2027  | 2.93 to 3.60 | 9550000 | 9970797 |
| US Treasury Bonds Series 2026, 6.75% 8/15/2026  | 3.94 | 2423000 | 2491525 |
| US Treasury Notes 0.375% 7/31/2027  | 0.91 to 3.51 | 82414000 | 77501353 |
| US Treasury Notes 0.375% 9/30/2027  | 3.68 | 61826000 | 57850781 |
| US Treasury Notes 0.5% 10/31/2027  | 3.78 to 4.23 | 119200000 | 111545125 |
| US Treasury Notes 0.5% 4/30/2027  | 1.95 to 4.09 | 119444000 | 113387817 |
| US Treasury Notes 0.5% 5/31/2027  | 0.55 to 3.64 | 38920000 | 36859976 |
| US Treasury Notes 0.5% 6/30/2027  | 0.49 to 4.03 | 25881000 | 24453501 |
| US Treasury Notes 0.5% 8/31/2027  | 1.13 to 2.86 | 76109000 | 71572190 |
| US Treasury Notes 0.625% 11/30/2027  | 4.18 | 28200700 | 26410617 |
| US Treasury Notes 0.625% 12/31/2027  | 3.30 | 15039900 | 14047032 |
| US Treasury Notes 0.625% 3/31/2027  | 0.51 | 17704000 | 16878966 |
| US Treasury Notes 0.625% 5/15/2030  | 0.80 to 3.52 | 154627000 | 134374487 |
| US Treasury Notes 0.625% 8/15/2030  | 3.18 to 4.31 | 129794900 | 111851769 |
| US Treasury Notes 0.75% 1/31/2028  | 0.99 to 1.28 | 122528000 | 114525390 |
| US Treasury Notes 0.875% 11/15/2030  | 3.02 to 3.72 | 64580900 | 55978523 |
| US Treasury Notes 0.875% 9/30/2026  | 4.47 | 62577000 | 60633691 |
| US Treasury Notes 1% 7/31/2028  | 3.07 to 3.92 | 117409000 | 109075713 |
| US Treasury Notes 1.125% 10/31/2026  | 3.04 | 107215000 | 103948293 |
| US Treasury Notes 1.125% 2/28/2027  | 3.63 to 4.57 | 85938000 | 82735467 |
| US Treasury Notes 1.125% 2/29/2028  | 1.28 to 3.05 | 29970000 | 28222140 |
| US Treasury Notes 1.125% 8/31/2028  | 2.95 to 4.65 | 129007000 | 120036982 |
| US Treasury Notes 1.25% 11/30/2026  | 1.24 to 3.75 | 76047000 | 73718061 |
| US Treasury Notes 1.25% 12/31/2026  | 1.61 to 4.30 | 85700000 | 82924793 |
| US Treasury Notes 1.25% 3/31/2028  | 1.41 to 2.96 | 39508000 | 37248636 |
| US Treasury Notes 1.25% 4/30/2028  | 3.55 to 4.18 | 26499000 | 24941149 |
| US Treasury Notes 1.25% 5/31/2028  | 2.94 to 3.62 | 51374000 | 48253431 |
| US Treasury Notes 1.25% 6/30/2028  | 3.04 to 4.16 | 147635000 | 138436647 |
| US Treasury Notes 1.25% 8/15/2031  | 1.62 to 4.49 | 207366000 | 179185284 |
| US Treasury Notes 1.25% 9/30/2028  | 3.65 | 3038000 | 2831986 |
| US Treasury Notes 1.375% 10/31/2028  | 4.27 | 30000000 | 28025391 |
| US Treasury Notes 1.375% 11/15/2031  | 3.04 to 3.44 | 58246000 | 50330459 |
| US Treasury Notes 1.375% 12/31/2028  | 1.56 | 23700000 | 22063219 |
| US Treasury Notes 1.5% 1/31/2027  | 1.84 to 3.89 | 65000000 | 63001758 |
| US Treasury Notes 1.5% 11/30/2028  | 3.09 | 42500000 | 39792285 |
| US Treasury Notes 1.5% 2/15/2030  | 2.99 to 3.64 | 30793000 | 28093801 |
| US Treasury Notes 1.625% 10/31/2026  | 0.57 to 1.73 | 87777000 | 85610005 |
| US Treasury Notes 1.625% 11/30/2026  | 1.12 | 9625000 | 9374600 |
| US Treasury Notes 1.625% 5/15/2031  | 1.39 to 4.41 | 213693000 | 190211813 |
| US Treasury Notes 1.625% 8/15/2029  | 2.67 to 4.34 | 121862000 | 113126970 |
| US Treasury Notes 1.625% 9/30/2026  | 3.82 to 4.59 | 75600000 | 73848797 |
| US Treasury Notes 1.75% 1/31/2029  | 2.00 to 4.20 | 76700000 | 72166910 |
| US Treasury Notes 1.75% 11/15/2029  | 3.01 to 3.89 | 21907000 | 20331579 |
| US Treasury Notes 1.75% 12/31/2026  | 3.64 | 39400000 | 38381140 |
| US Treasury Notes 1.875% 2/15/2032  | 2.90 to 4.34 | 83500000 | 73974479 |
| US Treasury Notes 1.875% 2/28/2027  | 3.07 | 28700000 | 27934293 |
| US Treasury Notes 1.875% 2/28/2029  | 3.08 | 2900000 | 2736195 |
| US Treasury Notes 2% 11/15/2026  | 0.49 | 30050000 | 29417307 |
| US Treasury Notes 2.25% 11/15/2027  | 4.33 | 22300000 | 21661488 |
| US Treasury Notes 2.25% 2/15/2027  | 2.40 to 3.18 | 44880000 | 43949091 |
| US Treasury Notes 2.25% 8/15/2027  | 3.34 | 15984000 | 15568166 |
| US Treasury Notes 2.375% 3/31/2029  | 4.11 to 4.23 | 87300000 | 83702285 |
| US Treasury Notes 2.375% 4/30/2026  | 0.46 | 9000 | 8904 |
| US Treasury Notes 2.375% 5/15/2027  | 0.55 to 2.98 | 7901000 | 7733104 |
| US Treasury Notes 2.375% 5/15/2029  | 0.74 to 4.37 | 162799000 | 155841886 |
| US Treasury Notes 2.625% 2/15/2029  | 1.40 to 2.51 | 58844000 | 56982139 |
| US Treasury Notes 2.625% 7/31/2029  | 3.56 to 3.75 | 29600000 | 28520062 |
| US Treasury Notes 2.75% 2/15/2028  | 0.64 to 4.32 | 91818200 | 90014116 |
| US Treasury Notes 2.75% 4/30/2027  | 2.94 | 21100000 | 20785148 |
| US Treasury Notes 2.75% 5/31/2029  | 4.52 | 92800000 | 89987000 |
| US Treasury Notes 2.75% 7/31/2027  | 4.10 to 4.50 | 30800000 | 30291078 |
| US Treasury Notes 2.75% 8/15/2032  | 3.94 to 4.14 | 69000000 | 64064883 |
| US Treasury Notes 2.875% 4/30/2029  | 2.88 to 3.49 | 74400000 | 72516750 |
| US Treasury Notes 2.875% 5/15/2028  | 3.03 to 4.46 | 52785000 | 51813838 |
| US Treasury Notes 2.875% 5/15/2032  | 3.02 to 4.10 | 126700000 | 119008915 |
| US Treasury Notes 2.875% 8/15/2028  | 1.28 to 4.00 | 92876000 | 91029364 |
| US Treasury Notes 3.125% 11/15/2028  | 2.49 to 2.88 | 26503000 | 26125125 |
| US Treasury Notes 3.125% 8/31/2027  | 4.08 | 49400000 | 48927227 |
| US Treasury Notes 3.125% 8/31/2029  | 4.48 | 29133900 | 28587639 |
| US Treasury Notes 3.25% 6/30/2027  | 3.58 | 73300000 | 72787472 |
| US Treasury Notes 3.25% 6/30/2029  | 3.08 | 34300000 | 33837754 |
| US Treasury Notes 3.375% 5/15/2033  | 3.96 to 4.91 | 101900000 | 97668761 |
| US Treasury Notes 3.5% 1/31/2030  | 3.60 | 47900000 | 47580043 |
| US Treasury Notes 3.5% 2/15/2033  | 3.82 to 4.53 | 61800000 | 59902547 |
| US Treasury Notes 3.625% 3/31/2030  | 4.31 | 6500000 | 6485781 |
| US Treasury Notes 3.625% 8/15/2028  | 3.58 | 40100000 | 40153258 |
| US Treasury Notes 3.625% 8/31/2027  | 3.61 | 27100000 | 27105293 |
| US Treasury Notes 3.625% 8/31/2030  | 3.69 | 1000000 | 996953 |
| US Treasury Notes 3.625% 9/30/2031  | 4.22 | 2000000 | 1977500 |
| US Treasury Notes 3.75% 6/30/2030  | 4.08 to 4.26 | 72300000 | 72494871 |
| US Treasury Notes 3.75% 8/15/2027  | 3.89 | 81700000 | 81862762 |
| US Treasury Notes 3.875% 10/15/2027  | 4.12 | 900000 | 904534 |
| US Treasury Notes 3.875% 11/30/2027  | 4.01 | 6500000 | 6536309 |
| US Treasury Notes 3.875% 11/30/2029  | 3.99 | 2100000 | 2117883 |
| US Treasury Notes 3.875% 12/31/2029  | 3.63 to 4.34 | 22300000 | 22492512 |
| US Treasury Notes 3.875% 4/30/2030  | 3.96 | 35600000 | 35901766 |
| US Treasury Notes 3.875% 7/15/2028  | 3.89 | 13800000 | 13906734 |
| US Treasury Notes 3.875% 7/31/2027  | 3.94 | 54700000 | 54926492 |
| US Treasury Notes 3.875% 7/31/2030  | 3.69 to 3.95 | 58700000 | 59172352 |
| US Treasury Notes 3.875% 8/15/2033  | 4.03 to 4.57 | 42100000 | 41659266 |
| US Treasury Notes 3.875% 8/15/2034  | 3.92 to 4.28 | 83000000 | 81378910 |
| US Treasury Notes 3.875% 9/30/2029  | 4.08 | 4900000 | 4943449 |
| US Treasury Notes 4% 1/15/2027  | 4.39 | 76700000 | 76936692 |
| US Treasury Notes 4% 1/31/2029  | 3.90 | 1400000 | 1417555 |
| US Treasury Notes 4% 1/31/2031  | 4.19 to 4.28 | 113000000 | 114341875 |
| US Treasury Notes 4% 10/31/2029  | 4.12 | 11200000 | 11351375 |
| US Treasury Notes 4% 2/15/2034  | 4.24 to 4.69 | 97000000 | 96431640 |
| US Treasury Notes 4% 3/31/2030  | 3.95 | 32700000 | 33148348 |
| US Treasury Notes 4% 4/30/2032  | 4.16 | 32400000 | 32587313 |
| US Treasury Notes 4% 5/31/2030  | 3.78 | 26100000 | 26461934 |
| US Treasury Notes 4% 6/30/2028  | 4.41 | 15400000 | 15572047 |
| US Treasury Notes 4% 6/30/2032  | 3.99 | 29500000 | 29652109 |
| US Treasury Notes 4% 7/31/2030  | 4.05 to 4.35 | 35300000 | 35764691 |
| US Treasury Notes 4% 7/31/2032  | 3.92 to 4.14 | 45800000 | 46007531 |
| US Treasury Notes 4.125% 10/31/2029  | 3.70 to 4.15 | 46700000 | 47544613 |
| US Treasury Notes 4.125% 10/31/2031  | 4.13 | 5500000 | 5584004 |
| US Treasury Notes 4.125% 11/15/2027  | 3.89 to 4.11 | 52900000 | 53462063 |
| US Treasury Notes 4.125% 11/15/2032  | 4.32 to 4.34 | 45600000 | 46109438 |
| US Treasury Notes 4.125% 11/30/2029  | 3.69 to 4.08 | 64800000 | 65987156 |
| US Treasury Notes 4.125% 2/15/2027  | 4.30 | 8700000 | 8745879 |
| US Treasury Notes 4.125% 2/29/2032  | 3.92 | 36600000 | 37107539 |
| US Treasury Notes 4.125% 3/31/2029  | 4.01 | 30600000 | 31119961 |
| US Treasury Notes 4.125% 3/31/2032  | 4.08 | 37700000 | 38208066 |
| US Treasury Notes 4.125% 9/30/2027  | 3.56 to 3.83 | 51700000 | 52221039 |
| US Treasury Notes 4.25% 11/15/2034  | 4.19 to 4.58 | 75300000 | 75794156 |
| US Treasury Notes 4.25% 11/30/2026  | 4.15 | 8120000 | 8163138 |
| US Treasury Notes 4.25% 12/31/2026  | 4.25 | 32900000 | 33096629 |
| US Treasury Notes 4.25% 2/15/2028  | 3.76 | 42000000 | 42638996 |
| US Treasury Notes 4.25% 2/28/2031  | 4.32 | 10600000 | 10855477 |
| US Treasury Notes 4.25% 5/15/2035  | 4.23 to 4.39 | 70700000 | 70920938 |
| US Treasury Notes 4.25% 8/15/2035  | 4.22 | 25800000 | 25852406 |
| US Treasury Notes 4.375% 1/31/2032  | 4.11 to 4.44 | 18500000 | 19017422 |
| US Treasury Notes 4.375% 11/30/2030  | 3.87 | 21500000 | 22149199 |
| US Treasury Notes 4.375% 12/15/2026  | 4.50 | 32800000 | 33040875 |
| US Treasury Notes 4.375% 12/31/2029  | 4.39 | 17600000 | 18098437 |
| US Treasury Notes 4.375% 5/15/2034  | 4.34 to 4.49 | 80500000 | 82072266 |
| US Treasury Notes 4.5% 11/15/2033  | 4.07 to 4.34 | 74000000 | 76306719 |
| US Treasury Notes 4.5% 12/31/2031  | 4.24 to 4.49 | 23100000 | 23917523 |
| US Treasury Notes 4.5% 5/15/2027  | 4.68 | 3000000 | 3039961 |
| US Treasury Notes 4.5% 5/31/2029  | 3.78 to 3.93 | 66500000 | 68510586 |
| US Treasury Notes 4.625% 10/15/2026  | 4.06 | 25700000 | 25922867 |
| US Treasury Notes 4.625% 2/15/2035  | 4.16 to 4.21 | 74000000 | 76532191 |
| US Treasury Notes 4.625% 4/30/2029  | 3.91 to 4.72 | 50100000 | 51810445 |
| US Treasury Notes 4.625% 5/31/2031  | 4.29 | 1200000 | 1250859 |
| US Treasury Notes 4.625% 9/30/2030  | 4.33 | 2900000 | 3020758 |
| US Treasury Notes 4.875% 10/31/2030  | 4.06 | 26300000 | 27705406 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $9,211,029,638) |  |  | **8869016686** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $51,518,105)<br>| 4.36 | 51507803 | **51518105** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 99.4%**<br> (Cost $9,262,547,743)<br>| <br>**8920534791** |
| **NET OTHER ASSETS (LIABILITIES) - 0.6%**  | **50928955** |
| **NET ASSETS - 100.0%** | **8971463746** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 38080938 | 423409583 | 409972416 | 570847 | - | - | 51518105 | 51507803 | 0.1% |
| Fidelity Securities Lending Cash Central Fund | 20724788 | 359564548 | 380289336 | 9145 | - | - | - | - | 0.0% |
| Total | 58805726 | 782974131 | 790261752 | 579992 | - | - | 51518105 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts in the dividend income column for Fidelity Securities Lending Cash Central Fund represents the income earned on investing cash collateral, less rebates paid to borrowers and any lending agent fees associated with the loan, plus any premium income received for lending certain types of securities.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 8869016686 | - | 8869016686 | - |
|  **Money Market Funds** | 51518105 | 51518105 | - | - |
| **Total Investments in Securities:** | 8920534791 | 51518105 | 8869016686 | - |

---

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $9,211,029,638) | $8869016686 |  |
| Fidelity Central Funds (cost $51,518,105) | 51518105 |  |
| Total Investment in Securities (cost $9,262,547,743) |  | $8920534791 |
| Receivable for investments sold |  | 187761095 |
| Receivable for fund shares sold |  | 2104817 |
| Interest receivable |  | 53821932 |
| Distributions receivable from Fidelity Central Funds |  | 89872 |
| Prepaid expenses |  | 10656 |
| Receivable from investment adviser for expense reductions |  | 82867 |
| **Total assets** |  | 9164406030 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $189032547 |  |
| Payable for fund shares redeemed | 2955898 |  |
| Distributions payable | 607217 |  |
| Accrued management fee | 296266 |  |
| Other payables and accrued expenses | 50356 |  |
| **Total liabilities** |  | 192942284 |
| **Net Assets**  |  | $8971463746 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $10629816125 |
| Total accumulated earnings (loss) |  | (1658352379) |
| **Net Assets** |  | $8971463746 |
| **Net Asset Value**, offering price and redemption price per share ($8,971,463,746 ÷ 1,011,969,186 shares) |  | $8.87 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $159858550 |
| Income from Fidelity Central Funds (including $9,145 from security lending)  |  | 579992 |
| **Total income** |  | 160438542 |
| **Expenses** |  |  |
| Management fee | $1769039 |  |
| Custodian fees and expenses | 30131 |  |
| Independent trustees' fees and expenses | 10376 |  |
| Registration fees | 28359 |  |
| Audit fees | 30796 |  |
| Legal | 2377 |  |
| Miscellaneous | 26841 |  |
| Total expenses before reductions | 1897919 |  |
| Expense reductions | (549733) |  |
| Total expenses after reductions |  | 1348186 |
| **Net Investment income (loss)** |  | 159090356 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (79278622) |  |
| Total net realized gain (loss) |  | (79278622) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | 72270452 |
| **Net gain (loss)** |  | (7008170) |
| **Net increase (decrease) in net assets resulting from operations** |  | $152082186 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **Year ended**<br> **February 28, 2025** |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $159090356 | $479279408 |
| &nbsp;&nbsp;Net realized gain (loss) | (79278622)<br>| (462614985)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | 72270452 | 705454556<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | 152082186<br>| 722118979<br>|
| Distributions to shareholders | (114432410)<br>| (386942076)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 942198594 | 3586242122 |
| Reinvestment of distributions | 111133673<br>| 363499888<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (1704246062) | (10543429760) |
| **Net increase (decrease) in net assets resulting from share transactions** | (650913795)<br>| (6593687750)<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | (613264019)<br>| (6258510847)<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 9584727765 | 15843238612<br>|
| &nbsp;&nbsp;End of period | $8971463746 | $9584727765 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 107120083 | 410322514 |
| Issued in reinvestment of distributions | 12589091<br>| 41664334<br>|
| &nbsp;&nbsp;Redeemed | (193505070) | (1196217162) |
| &nbsp;&nbsp;Net increase (decrease) | (73795896) | (744230314) |

---

**Financial Highlights** 

**Fidelity® SAI U.S. Treasury Bond Index Fund** <br>

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025**  | **2024** A  | **2023**  | **2022**  | **2021**  |
| **Selected Per-Share Data**  |  |  |  |  |  |  |
| Net asset value, beginning of period  | $8.83 | $8.66 | $8.66 | $9.79 | $10.10 | $10.60 |
| Income from Investment Operations  |  |  |  |  |  |  |
| Net investment income (loss) B,C | .158  | .307  | .257  | .184  | .106  | .168  |
| Net realized and unrealized gain (loss)  | (.004)  | .116  | (.063)  | (1.170)  | (.316)  | (.191)  |
| Total from investment operations  | .154  | .423  | .194  | (.986)  | (.210)  | (.023)  |
| Distributions from net investment income  | (.114)  | (.253)  | (.194)  | (.144)  | (.098)  | (.175)  |
| Distributions from net realized gain  | -  | -  | -  | -  | (.002)  | (.302)  |
| Total distributions  | (.114)  | (.253)  | (.194)  | (.144)  | (.100)  | (.477)  |
| Net asset value, end of period  | $8.87 | $8.83 | $8.66 | $8.66 | $9.79 | $10.10 |
| **Total Return** D,E | 1.75% <br>| 4.96%  | 2.25%  | (10.10)%  | (2.09)%  | (.33)%  |
| **Ratios to Average Net Assets** C,F,G |  |  |  |  |  |  |
| Expenses before reductions  | .04% H | .04%  | .05%  | .05%  | .05%  | .05%  |
| Expenses net of fee waivers, if any  | .03% H<br>| .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of all reductions, if any  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Net investment income (loss)  | 3.57% H | 3.51%  | 2.97%  | 2.05%  | 1.06%  | 1.56%  |
| **Supplemental Data** |  |  |  |  |  |  |
| Net assets, end of period (000 omitted) | $8971464 | $9584728 | $15843239 | $13457181 | $11227354 | $9575368 |
| Portfolio turnover rate I | 28% H<br>| 32%  | 37%  | 60%  | 45%  | 167%  |

---

A*For the year ended February 29.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*Total returns for periods of less than one year are not annualized.*

E*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

F*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

G*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

H*Annualized.*

I*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

**Notes to Financial Statements** **(Unaudited)**

For the period ended August 31, 2025

**1. Organization.**

Fidelity SAI U.S. Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered exclusively to certain clients of Fidelity Management & Research Company LLC (FMR) or its affiliates. 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.

**2. Investments in Fidelity Central Funds.**

Funds may invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Schedule of Investments lists any Fidelity Central Funds held as an investment as of period end, but does not include the underlying holdings of each Fidelity Central Fund. An investing fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

Based on its investment objective, each Fidelity Central Fund may invest or participate in various investment vehicles or strategies that are similar to those of the investing fund. These strategies are consistent with the investment objectives of the investing fund and may involve certain economic risks which may cause a decline in value of each of the Fidelity Central Funds and thus a decline in the value of the investing fund.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fidelity Central Fund** | **Investment Manager** | **Investment Objective** | **Investment Practices** | **Expense RatioA** |
| Fidelity Money Market Central Funds | Fidelity Management & Research Company LLC (FMR) | Each fund seeks to obtain a high level of current income consistent with the preservation of capital and liquidity. | Short-term Investments | Less than .005% |

---

*A Expenses expressed as a percentage of average net assets and are as of each underlying Central Fund's most recent annual or semi-annual shareholder report.* 

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds which contain the significant accounting policies (including investment valuation policies) of those funds, and are not covered by the Report of Independent Registered Public Accounting Firm, are available on the Securities and Exchange Commission website or upon request.

**3. Significant Accounting Policies.**

The Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 *Financial Services - Investment Companies*. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. The Fund operates as a single operating segment. The Fund's income, expenses, assets, and performance are regularly monitored and assessed as a whole by the investment adviser and other individuals responsible for oversight functions of the Trust, using the information presented in the financial statements and financial highlights. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The Fund's Schedule of Investments lists any underlying mutual funds or exchange-traded funds but does not include the underlying holdings of these funds. The following summarizes the significant accounting policies of the Fund:

**Investment Valuation.** Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has designated the Fund's investment adviser as the valuation designee responsible for the fair valuation function and performing fair value determinations as needed. The investment adviser has established a Fair Value Committee (the Committee) to carry out the day-to-day fair valuation responsibilities and has adopted policies and procedures to govern the fair valuation process and the activities of the Committee. In accordance with these fair valuation policies and procedures, which have been approved by the Board, the Fund attempts to obtain prices from one or more third party pricing services or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with the policies and procedures. Factors used in determining fair value vary by investment type and may include market or investment specific events, transaction data, estimated cash flows, and market observations of comparable investments. The frequency that the fair valuation procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee manages the Fund's fair valuation practices and maintains the fair valuation policies and procedures. The Fund's investment adviser reports to the Board information regarding the fair valuation process and related material matters.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing services or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing services who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing services. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of August 31, 2025 is included at the end of the Fund's Schedule of Investments.

**Investment Transactions and Income.** For financial reporting purposes, the Fund's investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

**Expenses.** Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

**Income Tax Information and Distributions to Shareholders.** Each year, the Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. The Fund files a U.S. federal tax return, in addition to state and local tax returns as required. The Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

---

| | |
|:---|:---|
| **Gross unrealized appreciation** | $187686894 |
| **Gross unrealized depreciation** | <u>(352502807)</u> |
| **Net unrealized appreciation (depreciation)** | <u>$(164815913)</u> |
| **Tax cost** | <u>$9085350704</u> |

---

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of prior fiscal period end and is subject to adjustment.

---

| | |
|:---|:---|
| Short-term | $(316999342) |
| Long-term | <u>(1151658134)</u> |
| **Total capital loss carryforward** | <u>$(1468657476)</u> |

---

**New Accounting Pronouncement.** 

In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures. Effective for annual periods beginning after December 15, 2024, the amendments require greater disaggregation of disclosures related to income taxes paid. The ASU allows for early adoption and amendments should be applied on a prospective basis. Management is currently evaluating the impact of the ASU but does not expect this guidance to materially impact the financial statements.

**4. Fees and Other Transactions with Affiliates.**

**Management Fee.** Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund pays a monthly management fee that is based on an annual rate of .04% of the Fund's average net assets.

**Interfund Trades.** Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board of Trustees. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Any interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note. During the period, there were no interfund trades.

**5. Committed Line of Credit.**

Certain Funds participate with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes.

Commitment fees are charged based on the unused amount of the line of credit at an annual rate of .10%, and then allocated to each participating fund based on its pro-rata portion of the line of credit. The commitment fees are reflected in Miscellaneous expenses on the Statement of Operations, and are listed below.

Interest is charged to a participating fund based on its borrowings at an annual rate of .75% plus the highest of (i) daily SOFR plus a .10% spread adjustment, (ii) Federal Funds Effective Rate, or (iii) Overnight Bank Funding Rate. During the period, there were no borrowings on this line of credit.

The line of credit agreement will expire in March 2026 unless extended or renewed.

---

| | |
|:---|:---|
|  | **Amount ($)** |
| **Fidelity SAI U.S. Treasury Bond Index Fund** | 7236 |

---

**6. Security Lending.** 

Funds lend portfolio securities from time to time in order to earn additional income. Lending agents are used, including National Financial Services (NFS), an affiliate of the investment adviser. Pursuant to a securities lending agreement, NFS will receive a fee, which is capped at 9.9% of a fund's daily lending revenue, for its services as lending agent. A fund may lend securities to certain qualified borrowers, including NFS. On the settlement date of the loan, the borrowers provide collateral (in the form of U.S. Treasury obligations, letters of credit and/or cash) against the loaned securities and maintains collateral in an amount not less than 100% of the fair value of the loaned securities during the period of the loan. The fair value of the loaned securities is determined at the close of business of a fund and any additional required collateral is delivered to a fund on the next business day. A fund or borrower may terminate the loan at any time, and if the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund may apply collateral received from the borrower against the obligation. A fund may experience delays and costs in recovering the securities loaned or gaining access to non-cash collateral. Any cash collateral received is invested in the Fidelity Securities Lending Cash Central Fund. Any loaned securities are identified as such in the Schedule of Investments, and the value of loaned securities and cash collateral at period end, as applicable, are presented in the Statement of Assets and Liabilities. Security lending income represents the income earned on investing cash collateral less rebates paid to borrowers, plus any premium income received, or for non-cash collateral, fees received from borrowers as compensation for the securities loaned. Securities lending income is reduced by any lending agent fees associated with the loan. Any security lending income earned on investing cash collateral is presented in the Statement of Operations as a component of income from Fidelity Central Funds. Any security lending income earned on non-cash collateral is presented in the Statement of Operations as a component of interest. Affiliated security lending activity, if any, was as follows:

---

| | | | |
|:---|:---|:---|:---|
|  | **Total Security Lending Fees Paid to NFS ($)** | **Security Lending Income From Securities Loaned to NFS ($)** | **Value of Securities Loaned to NFS at Period End ($)** |
| **Fidelity SAI U.S. Treasury Bond Index Fund** | 986 | - | - |

---

**7. Expense Reductions.** 

The investment adviser contractually agreed to reimburse the Fund to the extent annual operating expenses exceeded .03% of average net assets. This reimbursement will remain in place through June 30, 2026. Some expenses, for example the compensation of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses, are excluded from this reimbursement. During the period this reimbursement reduced the Fund's expenses by $549,733.

**8. Other.**

A fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the fund. In the normal course of business, a fund may also enter into contracts that provide general indemnifications. A fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against a fund. The risk of material loss from such claims is considered remote.

In addition, at the end of the period, the following mutual funds managed by the investment adviser or its affiliates were the owners of record of 10% or more of the total outstanding shares.

---

| | |
|:---|:---|
|  | **Strategic Advisers Fidelity Core Income Fund** |
| **Fidelity SAI U.S. Treasury Bond Index Fund** | 62% |

---

Mutual funds managed by the investment adviser or its affiliates, in aggregate, were the owners of record of more than 20% of the total outstanding shares.

---

| | |
|:---|:---|
| **Fund**  | **% of shares held** |
| **Fidelity SAI U.S. Treasury Bond Index Fund** | 65% |

---

**9. Risk and Uncertainties.**

Many factors affect a fund's performance. Developments that disrupt global economies and financial markets, such as public health emergencies, military conflicts, terrorism, government restrictions, political changes, and environmental disasters, may significantly affect a fund's investment performance. The effects of these developments to a fund will be impacted by the types of securities in which a fund invests, the financial condition, industry, economic sector, and geographic location of an issuer, and a fund's level of investment in the securities of that issuer. Significant concentrations in security types, issuers, industries, sectors, and geographic locations may magnify the factors that affect a fund's performance.

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

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 9: Proxy Disclosures for Open-End Management Investment Companies**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies**

**(Unaudited)**

Note: This information is disclosed as part of the financial statements for each Fund as part of Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies.

**Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

![](img114163_4.jpg)<br>

1.9872607.109 UYB-SANN-1025

**Fidelity® SAI Long-Term Treasury Bond Index Fund**

**Semi-Annual Report**

**August 31, 2025**

Offered exclusively to certain clients of the Adviser, or its affiliates, including Strategic Advisers LLC (Strategic Advisers) - not available for sale to the general public. Fidelity® SAI is a product name of Fidelity® funds dedicated to certain programs affiliated with Strategic Advisers.

![](img114164_1.jpg)

![](img114164_2.jpg)

**Contents**

---

| |
|:---|
| **[Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)](#Sec_Item7_SV5-SANN_0)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® SAI Long-Term Treasury Bond Index Fund](#Sub_Sec_Fund_2801_SV5-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Notes to Financial Statements](#Sub_Sec_NotestoFinancialStatements2801_SV5-SANN)** |
| **[Item 8: Changes in and Disagreements with Accountants for Open-End Management Investment Companies](#Sec_Item8_SV5-SANN)** |
| **[Item 9: Proxy Disclosures for Open-End Management Investment Companies](#Sec_Item9_SV5-SANN)** |
| **[Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies](#Sec_Item10_SV5-SANN)** |
| **[Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract](#Sec_Item11_SV5-SANN)** |

---

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov.

You may also call 1-800-544-3455 to request a free copy of the proxy voting guidelines.

"BLOOMBERG®" and the Bloomberg indices listed herein (the "Indices") are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL"), the administrator of the Indices (collectively, "Bloomberg") and have been licensed for use for certain purposes by Fidelity. Bloomberg is not affiliated with Fidelity, and Bloomberg does not approve, endorse, review, or recommend the fund. Bloomberg does not guarantee the timeliness, accuracy, or completeness of any data or information relating to the fund.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.© 2025 FMR LLC. All rights reserved.

*This report and the financial statements contained herein are submitted for the general information of the shareholders of the Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.*

*A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. Forms N-PORT are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-PORT may be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.*

*For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.*

**NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE**

*Neither the Fund nor Fidelity Distributors Corporation is a bank.*

**Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)**

**Fidelity® SAI Long-Term Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 1.25% 5/15/2050  | 4.76 to 5.02 | 152200000 | 71718305 |
| US Treasury Bonds 1.375% 8/15/2050  | 4.72 to 5.12 | 140300000 | 67782438 |
| US Treasury Bonds 1.625% 11/15/2050  | 2.39 to 5.18 | 103942000 | 53627576 |
| US Treasury Bonds 1.875% 11/15/2051  | 3.05 to 5.02 | 229400000 | 124843781 |
| US Treasury Bonds 1.875% 2/15/2051  | 2.40 to 5.02 | 155713000 | 85660398 |
| US Treasury Bonds 2% 2/15/2050  | 3.60 to 5.02 | 123443800 | 71259862 |
| US Treasury Bonds 2% 8/15/2051  | 2.16 to 5.16 | 224588000 | 126751853 |
| US Treasury Bonds 2.25% 2/15/2052  | 3.33 to 4.69 | 158400000 | 94687313 |
| US Treasury Bonds 2.25% 8/15/2046  | 4.49 to 5.01 | 64554000 | 41823931 |
| US Treasury Bonds 2.25% 8/15/2049  | 4.72 to 5.10 | 122400000 | 75534188 |
| US Treasury Bonds 2.375% 11/15/2049  | 4.67 to 4.74 | 113700000 | 71959663 |
| US Treasury Bonds 2.375% 5/15/2051  | 3.53 to 4.78 | 423970000 | 263441048 |
| US Treasury Bonds 2.5% 2/15/2046  | 2.09 to 3.94 | 106485000 | 73021257 |
| US Treasury Bonds 2.5% 5/15/2046  | 4.80 to 5.09 | 9500000 | 6494883 |
| US Treasury Bonds 2.75% 11/15/2047  | 4.46 to 4.94 | 80354000 | 56426713 |
| US Treasury Bonds 2.75% 8/15/2042  | 3.37 | 3500 | 2659 |
| US Treasury Bonds 2.75% 8/15/2047  | 3.48 to 4.92 | 204457000 | 144006413 |
| US Treasury Bonds 2.875% 11/15/2046  | 3.76 to 5.00 | 40096000 | 29194900 |
| US Treasury Bonds 2.875% 5/15/2043  | 3.31 | 20200 | 15448 |
| US Treasury Bonds 2.875% 5/15/2049  | 2.09 to 5.10 | 123218000 | 87133416 |
| US Treasury Bonds 2.875% 5/15/2052  | 3.30 to 4.75 | 178000000 | 122743515 |
| US Treasury Bonds 3% 11/15/2044  | 2.96 | 800 | 610 |
| US Treasury Bonds 3% 11/15/2045  | 4.86 to 4.96 | 51906000 | 39140368 |
| US Treasury Bonds 3% 2/15/2047  | 2.14 to 4.93 | 102746000 | 76321013 |
| US Treasury Bonds 3% 2/15/2048  | 3.74 to 5.04 | 87487000 | 64176499 |
| US Treasury Bonds 3% 2/15/2049  | 4.66 to 5.07 | 120900000 | 87817793 |
| US Treasury Bonds 3% 5/15/2047  | 2.57 to 5.09 | 52048000 | 38541950 |
| US Treasury Bonds 3% 8/15/2048  | 3.65 to 5.18 | 105655000 | 77103387 |
| US Treasury Bonds 3% 8/15/2052  | 3.52 to 4.24 | 277500000 | 196244531 |
| US Treasury Bonds 3.125% 2/15/2042  | 3.09 to 3.35 | 68100 | 55233 |
| US Treasury Bonds 3.125% 5/15/2048  | 3.18 to 5.10 | 76614000 | 57367725 |
| US Treasury Bonds 3.375% 11/15/2048  | 4.65 to 4.95 | 104800000 | 81780843 |
| US Treasury Bonds 3.625% 2/15/2053  | 3.66 to 4.65 | 195100000 | 156163833 |
| US Treasury Bonds 3.625% 5/15/2053  | 3.98 to 5.10 | 183400000 | 146641195 |
| US Treasury Bonds 4% 11/15/2052  | 3.84 to 5.01 | 100300000 | 86077773 |
| US Treasury Bonds 4.125% 8/15/2053  | 4.70 to 5.11 | 141700000 | 124103738 |
| US Treasury Bonds 4.25% 2/15/2054  | 4.55 to 5.02 | 182400000 | 163191000 |
| US Treasury Bonds 4.25% 8/15/2054  | 4.13 to 4.94 | 236490000 | 211584647 |
| US Treasury Bonds 4.5% 11/15/2054  | 4.37 to 4.97 | 191600000 | 178854109 |
| US Treasury Bonds 4.625% 2/15/2055  | 4.47 to 5.01 | 180800000 | 172325000 |
| US Treasury Bonds 4.625% 5/15/2054  | 4.12 to 4.96 | 184700000 | 175962824 |
| US Treasury Bonds 4.75% 11/15/2053  | 4.35 to 5.03 | 147400000 | 143288923 |
| US Treasury Bonds 4.75% 5/15/2055  | 4.79 to 4.96 | 199100000 | 193686969 |
| US Treasury Bonds 4.75% 8/15/2055  | 4.92 | 38900000 | 37854563 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $4,658,322,712) |  |  | **4176414086** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 1.2%** | &nbsp;&nbsp;**Money Market Funds - 1.2%** | &nbsp;&nbsp;**Money Market Funds - 1.2%** | &nbsp;&nbsp;**Money Market Funds - 1.2%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $49,005,872)<br>| 4.36 | 48996073 | **49005872** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 100.4%**<br> (Cost $4,707,328,584)<br>| <br>**4225419958** |
| **NET OTHER ASSETS (LIABILITIES) - (0.4)%**  | **(15986966)** |
| **NET ASSETS - 100.0%** | **4209432992** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 28487536 | 242468682 | 221950346 | 274487 | - | - | 49005872 | 48996073 | 0.1% |
| Total | 28487536 | 242468682 | 221950346 | 274487 | - | - | 49005872 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 4176414086 | - | 4176414086 | - |
|  **Money Market Funds** | 49005872 | 49005872 | - | - |
| **Total Investments in Securities:** | 4225419958 | 49005872 | 4176414086 | - |

---

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $4,658,322,712) | $4176414086 |  |
| Fidelity Central Funds (cost $49,005,872) | 49005872 |  |
| Total Investment in Securities (cost $4,707,328,584) |  | $4225419958 |
| Receivable for investments sold |  | 41089434 |
| Receivable for fund shares sold |  | 1950656 |
| Interest receivable |  | 29760358 |
| Distributions receivable from Fidelity Central Funds |  | 107049 |
| Prepaid expenses |  | 4816 |
| Receivable from investment adviser for expense reductions |  | 39852 |
| **Total assets** |  | 4298372123 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $86390953 |  |
| Payable for fund shares redeemed | 909337 |  |
| Distributions payable | 1464697 |  |
| Accrued management fee | 140416 |  |
| Other payables and accrued expenses | 33728 |  |
| **Total liabilities** |  | 88939131 |
| **Net Assets**  |  | $4209432992 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $7266374820 |
| Total accumulated earnings (loss) |  | (3056941828) |
| **Net Assets** |  | $4209432992 |
| **Net Asset Value**, offering price and redemption price per share ($4,209,432,992 ÷ 633,616,514 shares) |  | $6.64 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $85745468 |
| Income from Fidelity Central Funds  |  | 274487 |
| **Total income** |  | 86019955 |
| **Expenses** |  |  |
| Management fee | $736856 |  |
| Custodian fees and expenses | 205 |  |
| Independent trustees' fees and expenses | 4006 |  |
| Registration fees | 75114 |  |
| Audit fees | 29908 |  |
| Legal | 870 |  |
| Miscellaneous | 7321 |  |
| Total expenses before reductions | 854280 |  |
| Expense reductions | (293324) |  |
| Total expenses after reductions |  | 560956 |
| **Net Investment income (loss)** |  | 85458999 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (104820193) |  |
| Total net realized gain (loss) |  | (104820193) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | (116022650) |
| **Net gain (loss)** |  | (220842843) |
| **Net increase (decrease) in net assets resulting from operations** |  | $(135383844) |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **Year ended**<br> **February 28, 2025** |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $85458999 | $130921570 |
| &nbsp;&nbsp;Net realized gain (loss) | (104820193)<br>| (200556526)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | (116022650) | 156929312<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | (135383844)<br>| 87294356<br>|
| Distributions to shareholders | (75215663)<br>| (116632772)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 2080243914 | 88157475 |
| Reinvestment of distributions | 70102561<br>| 116259669<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (788208342) | (455291320) |
| **Net increase (decrease) in net assets resulting from share transactions** | 1362138133<br>| (250874176)<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 1151538626<br>| (280212592)<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 3057894366 | 3338106958<br>|
| &nbsp;&nbsp;End of period | $4209432992 | $3057894366 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 305334979 | 12299649 |
| Issued in reinvestment of distributions | 10397958<br>| 16488772<br>|
| &nbsp;&nbsp;Redeemed | (113976569) | (62141873) |
| &nbsp;&nbsp;Net increase (decrease) | 201756368 | (33353452) |

---

**Financial Highlights** 

**Fidelity® SAI Long-Term Treasury Bond Index Fund** <br>

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025**  | **2024** A  | **2023**  | **2022**  | **2021**  |
| **Selected Per-Share Data**  |  |  |  |  |  |  |
| Net asset value, beginning of period  | $7.08 | $7.18 | $7.73 | $10.71 | $11.04 | $12.59 |
| Income from Investment Operations  |  |  |  |  |  |  |
| Net investment income (loss) B,C | .155  | .297  | .283  | .243  | .219  | .227  |
| Net realized and unrealized gain (loss)  | (.458)  | (.132)  | (.582)  | (2.991)  | (.309)  | (.965)  |
| Total from investment operations  | (.303)  | .165  | (.299)  | (2.748)  | (.090)  | (.738)  |
| Distributions from net investment income  | (.137)  | (.265)  | (.251)  | (.232)  | (.213)  | (.226)  |
| Distributions from net realized gain  | -  | -  | -  | -  | (.027)  | (.586)  |
| Total distributions  | (.137)  | (.265)  | (.251)  | (.232)  | (.240)  | (.812)  |
| Net asset value, end of period  | $6.64 | $7.08 | $7.18 | $7.73 | $10.71 | $11.04 |
| **Total Return** D,E | (4.29)% <br>| 2.37%  | (3.91)%  | (25.78)%  | (.85)%  | (6.39)%  |
| **Ratios to Average Net Assets** C,F,G |  |  |  |  |  |  |
| Expenses before reductions  | .05% H | .04%  | .04%  | .04%  | .08%  | .05%  |
| Expenses net of fee waivers, if any  | .03% H<br>| .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of all reductions, if any  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Net investment income (loss)  | 4.60% H | 4.20%  | 3.85%  | 2.85%  | 1.97%  | 1.77%  |
| **Supplemental Data** |  |  |  |  |  |  |
| Net assets, end of period (000 omitted) | $4209433 | $3057894 | $3338107 | $3238850 | $7086638 | $1174635 |
| Portfolio turnover rate I | 35% H<br>| 20%  | 51%  | 107%  | 62%  | 47%  |

---

A*For the year ended February 29.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*Total returns for periods of less than one year are not annualized.*

E*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

F*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

G*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

H*Annualized.*

I*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

**Notes to Financial Statements** **(Unaudited)**

For the period ended August 31, 2025

**1. Organization.**

Fidelity SAI Long-Term Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered exclusively to certain clients of Fidelity Management & Research Company LLC (FMR) or its affiliates. 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.

**2. Investments in Fidelity Central Funds.**

Funds may invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Schedule of Investments lists any Fidelity Central Funds held as an investment as of period end, but does not include the underlying holdings of each Fidelity Central Fund. An investing fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

Based on its investment objective, each Fidelity Central Fund may invest or participate in various investment vehicles or strategies that are similar to those of the investing fund. These strategies are consistent with the investment objectives of the investing fund and may involve certain economic risks which may cause a decline in value of each of the Fidelity Central Funds and thus a decline in the value of the investing fund.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fidelity Central Fund** | **Investment Manager** | **Investment Objective** | **Investment Practices** | **Expense RatioA** |
| Fidelity Money Market Central Funds | Fidelity Management & Research Company LLC (FMR) | Each fund seeks to obtain a high level of current income consistent with the preservation of capital and liquidity. | Short-term Investments | Less than .005% |

---

*A Expenses expressed as a percentage of average net assets and are as of each underlying Central Fund's most recent annual or semi-annual shareholder report.* 

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds which contain the significant accounting policies (including investment valuation policies) of those funds, and are not covered by the Report of Independent Registered Public Accounting Firm, are available on the Securities and Exchange Commission website or upon request.

**3. Significant Accounting Policies.**

The Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 *Financial Services - Investment Companies*. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. The Fund operates as a single operating segment. The Fund's income, expenses, assets, and performance are regularly monitored and assessed as a whole by the investment adviser and other individuals responsible for oversight functions of the Trust, using the information presented in the financial statements and financial highlights. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The Fund's Schedule of Investments lists any underlying mutual funds or exchange-traded funds but does not include the underlying holdings of these funds. The following summarizes the significant accounting policies of the Fund:

**Investment Valuation.** Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has designated the Fund's investment adviser as the valuation designee responsible for the fair valuation function and performing fair value determinations as needed. The investment adviser has established a Fair Value Committee (the Committee) to carry out the day-to-day fair valuation responsibilities and has adopted policies and procedures to govern the fair valuation process and the activities of the Committee. In accordance with these fair valuation policies and procedures, which have been approved by the Board, the Fund attempts to obtain prices from one or more third party pricing services or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with the policies and procedures. Factors used in determining fair value vary by investment type and may include market or investment specific events, transaction data, estimated cash flows, and market observations of comparable investments. The frequency that the fair valuation procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee manages the Fund's fair valuation practices and maintains the fair valuation policies and procedures. The Fund's investment adviser reports to the Board information regarding the fair valuation process and related material matters.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing services or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing services who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing services. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of August 31, 2025 is included at the end of the Fund's Schedule of Investments.

**Investment Transactions and Income.** For financial reporting purposes, the Fund's investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

**Expenses.** Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

**Income Tax Information and Distributions to Shareholders.** Each year, the Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. The Fund files a U.S. federal tax return, in addition to state and local tax returns as required. The Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

---

| | |
|:---|:---|
| **Gross unrealized appreciation** | $5521840 |
| **Gross unrealized depreciation** | <u>(496928210)</u> |
| **Net unrealized appreciation (depreciation)** | <u>$(491406370)</u> |
| **Tax cost** | <u>$4716826328</u> |

---

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of prior fiscal period end and is subject to adjustment.

Due to large redemptions in a prior period, approximately $1,701,364,431 of the Fund's realized capital losses are subject to limitation. Due to this limitation, the Fund will only be permitted to use approximately $75,457,734 of those capital losses per year to offset capital gains. Additionally, the Fund is subject to an annual limit on its use of some of its unrealized capital losses to offset capital gains in future periods. If those losses are realized and the limitation prevents the Fund from using any of those losses in a future period, those capital losses will be available to offset capital gains in subsequent periods.

---

| | |
|:---|:---|
| Short-term | $(810967964) |
| Long-term | <u>(1683710174)</u> |
| **Total capital loss carryforward** | <u>$(2494678138)</u> |

---

**New Accounting Pronouncement.** 

In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures. Effective for annual periods beginning after December 15, 2024, the amendments require greater disaggregation of disclosures related to income taxes paid. The ASU allows for early adoption and amendments should be applied on a prospective basis. Management is currently evaluating the impact of the ASU but does not expect this guidance to materially impact the financial statements.

**4. Fees and Other Transactions with Affiliates.**

**Management Fee.** Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund pays a monthly management fee that is based on an annual rate of .04% of the Fund's average net assets.

**Interfund Trades.** Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board of Trustees. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Any interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note. During the period, there were no interfund trades.

**5. Committed Line of Credit.**

Certain Funds participate with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes.

Commitment fees are charged based on the unused amount of the line of credit at an annual rate of .10%, and then allocated to each participating fund based on its pro-rata portion of the line of credit. The commitment fees are reflected in Miscellaneous expenses on the Statement of Operations, and are listed below.

Interest is charged to a participating fund based on its borrowings at an annual rate of .75% plus the highest of (i) daily SOFR plus a .10% spread adjustment, (ii) Federal Funds Effective Rate, or (iii) Overnight Bank Funding Rate. During the period, there were no borrowings on this line of credit.

The line of credit agreement will expire in March 2026 unless extended or renewed.

---

| | |
|:---|:---|
|  | **Amount ($)** |
| **Fidelity SAI Long-Term Treasury Bond Index Fund** | 2573 |

---

**6. Expense Reductions.** 

The investment adviser contractually agreed to reimburse the Fund to the extent annual operating expenses exceeded .03% of average net assets. This reimbursement will remain in place through June 30, 2026. Some expenses, for example the compensation of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses, are excluded from this reimbursement. During the period this reimbursement reduced the Fund's expenses by $293,318.

Through arrangements with the Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses by $6.

**7. Other.**

A fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the fund. In the normal course of business, a fund may also enter into contracts that provide general indemnifications. A fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against a fund. The risk of material loss from such claims is considered remote.

At the end of the period, the following mutual funds managed by the investment adviser or its affiliates were the owners of record of 10% or more of the total outstanding shares.

---

| | |
|:---|:---|
|  | **Strategic Advisers Fidelity Core Income Fund** |
| Fidelity SAI Long-Term Treasury Bond Index Fund | 54% |

---

Mutual funds managed by the investment adviser or its affiliates, in aggregate, were the owners of record of more than 20% of the total outstanding shares.

---

| | |
|:---|:---|
| **Fund**  | **% of shares held** |
| Fidelity SAI Long-Term Treasury Bond Index Fund | 54% |

---

**8. Risk and Uncertainties.**

Many factors affect a fund's performance. Developments that disrupt global economies and financial markets, such as public health emergencies, military conflicts, terrorism, government restrictions, political changes, and environmental disasters, may significantly affect a fund's investment performance. The effects of these developments to a fund will be impacted by the types of securities in which a fund invests, the financial condition, industry, economic sector, and geographic location of an issuer, and a fund's level of investment in the securities of that issuer. Significant concentrations in security types, issuers, industries, sectors, and geographic locations may magnify the factors that affect a fund's performance.

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

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 9: Proxy Disclosures for Open-End Management Investment Companies**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies**

**(Unaudited)**

Note: This information is disclosed as part of the financial statements for each Fund as part of Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies.

**Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

![](img114164_4.jpg)<br>

1.9869415.109 SV5-SANN-1025

**Fidelity® Short-Term Treasury Bond Index Fund**

**Fidelity® Intermediate Treasury Bond Index Fund**

**Fidelity® Long-Term Treasury Bond Index Fund**

**Semi-Annual Report**

**August 31, 2025**

![](img114165_1.jpg)

![](img114165_2.jpg)

**Contents**

---

| |
|:---|
| **[Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)](#Sec_Item7_LBX-I-SANN_0)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® Short-Term Treasury Bond Index Fund](#Sub_Sec_Fund_1560_LBX-I-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® Intermediate Treasury Bond Index Fund](#Sub_Sec_Fund_1561_LBX-I-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® Long-Term Treasury Bond Index Fund](#Sub_Sec_Fund_1562_LBX-I-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Notes to Financial Statements](#Sub_Sec_NotestoFinancialStatements1560_LBX-I-SANN)** |
| **[Item 8: Changes in and Disagreements with Accountants for Open-End Management Investment Companies](#Sec_Item8_LBX-I-SANN)** |
| **[Item 9: Proxy Disclosures for Open-End Management Investment Companies](#Sec_Item9_LBX-I-SANN)** |
| **[Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies](#Sec_Item10_LBX-I-SANN)** |
| **[Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract](#Sec_Item11_LBX-I-SANN)** |

---

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov.

You may also call 1-800-544-8544 to request a free copy of the proxy voting guidelines.

"BLOOMBERG®" and the Bloomberg indices listed herein (the "Indices") are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL"), the administrator of the Indices (collectively, "Bloomberg") and have been licensed for use for certain purposes by Fidelity. Bloomberg is not affiliated with Fidelity, and Bloomberg does not approve, endorse, review, or recommend a fund. Bloomberg does not guarantee the timeliness, accuracy, or completeness of any data or information relating to a fund.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.© 2025 FMR LLC. All rights reserved.

*This report and the financial statements contained herein are submitted for the general information of the shareholders of the Funds. This report is not authorized for distribution to prospective investors in the Funds unless preceded or accompanied by an effective prospectus.*

*A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. Forms N-PORT are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-PORT may be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.*

*For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.*

**NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE**

*Neither the Funds nor Fidelity Distributors Corporation is a bank.*

**Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)**

**Fidelity® Short-Term Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 5.5% 8/15/2028  | 4.81 | 11019600 | 11617069 |
| US Treasury Bonds 6.375% 8/15/2027  | 4.07 | 12888100 | 13558684 |
| US Treasury Bonds 6.5% 11/15/2026  | 3.75 | 4120400 | 4264614 |
| US Treasury Notes 0.375% 7/31/2027  | 2.72 to 4.24 | 66256400 | 62306897 |
| US Treasury Notes 0.375% 9/30/2027  | 4.02 to 4.25 | 35693800 | 33398800 |
| US Treasury Notes 0.5% 10/31/2027  | 3.82 to 4.35 | 36508300 | 34163783 |
| US Treasury Notes 0.5% 4/30/2027  | 4.67 | 15906500 | 15099991 |
| US Treasury Notes 0.5% 5/31/2027  | 3.63 to 4.07 | 36843700 | 34893574 |
| US Treasury Notes 0.5% 6/30/2027  | 2.74 to 4.11 | 40772400 | 38523547 |
| US Treasury Notes 0.5% 8/31/2027  | 4.09 | 4444200 | 4179284 |
| US Treasury Notes 0.625% 11/30/2027  | 3.82 | 16385600 | 15345498 |
| US Treasury Notes 0.625% 12/31/2027  | 4.03 | 60272300 | 56293387 |
| US Treasury Notes 0.625% 3/31/2027  | 3.97 to 4.43 | 41107800 | 39192112 |
| US Treasury Notes 0.75% 1/31/2028  | 3.62 to 4.19 | 67075700 | 62694818 |
| US Treasury Notes 0.875% 9/30/2026  | 4.47 to 4.77 | 28411300 | 27528996 |
| US Treasury Notes 1% 7/31/2028  | 4.19 | 50833800 | 47225792 |
| US Treasury Notes 1.125% 10/31/2026  | 1.17 | 37562400 | 36417921 |
| US Treasury Notes 1.125% 2/29/2028  | 3.58 to 4.19 | 31961700 | 30097684 |
| US Treasury Notes 1.25% 11/30/2026  | 1.15 | 32148400 | 31163855 |
| US Treasury Notes 1.25% 12/31/2026  | 1.25 to 4.40 | 82407300 | 79738720 |
| US Treasury Notes 1.25% 3/31/2028  | 3.83 | 2347600 | 2213347 |
| US Treasury Notes 1.25% 4/30/2028  | 3.55 | 37754000 | 35534478 |
| US Treasury Notes 1.25% 5/31/2028  | 3.94 to 4.15 | 72441700 | 68041432 |
| US Treasury Notes 1.25% 6/30/2028  | 4.17 | 1197800 | 1123171 |
| US Treasury Notes 1.25% 9/30/2028  | 4.66 | 66740300 | 62214473 |
| US Treasury Notes 1.5% 1/31/2027  | 1.62 | 10888300 | 10553570 |
| US Treasury Notes 1.5% 8/15/2026  | 4.71 | 6707600 | 6559876 |
| US Treasury Notes 1.625% 10/31/2026  | 1.13 to 4.52 | 47288400 | 46120968 |
| US Treasury Notes 1.875% 2/28/2027  | 1.72 | 22422400 | 21824177 |
| US Treasury Notes 1.875% 2/28/2029  | 4.28 | 85809000 | 80962132 |
| US Treasury Notes 2.25% 11/15/2027  | 4.12 | 23284800 | 22618091 |
| US Treasury Notes 2.25% 2/15/2027  | 4.63 | 7761600 | 7600607 |
| US Treasury Notes 2.25% 8/15/2027  | 3.69 to 3.83 | 14277500 | 13906062 |
| US Treasury Notes 2.375% 3/31/2029  | 4.23 | 39814200 | 38173419 |
| US Treasury Notes 2.375% 5/15/2027  | 4.56 | 16912700 | 16553305 |
| US Treasury Notes 2.375% 5/15/2029  | 4.52 | 11834100 | 11328377 |
| US Treasury Notes 2.5% 3/31/2027  | 2.43 to 2.86 | 20362300 | 19990052 |
| US Treasury Notes 2.625% 5/31/2027  | 2.82 | 45276100 | 44476694 |
| US Treasury Notes 2.75% 2/15/2028  | 4.21 | 11211200 | 10990917 |
| US Treasury Notes 2.75% 4/30/2027  | 4.41 to 4.46 | 14756600 | 14536404 |
| US Treasury Notes 2.75% 5/31/2029  | 4.52 | 37658200 | 36516686 |
| US Treasury Notes 2.75% 7/31/2027  | 2.71 | 13415100 | 13193436 |
| US Treasury Notes 2.875% 4/30/2029  | 4.75 | 31332100 | 30539006 |
| US Treasury Notes 3.125% 8/31/2027  | 4.07 | 6174800 | 6115705 |
| US Treasury Notes 3.25% 6/30/2027  | 3.04 | 8671900 | 8611264 |
| US Treasury Notes 3.375% 9/15/2027  | 3.56 | 12500000 | 12441406 |
| US Treasury Notes 3.5% 1/31/2028  | 3.60 to 4.19 | 56870600 | 56739531 |
| US Treasury Notes 3.5% 1/31/2030  | 3.90 | 7450000 | 7400236 |
| US Treasury Notes 3.5% 4/30/2028  | 4.47 | 1533200 | 1529567 |
| US Treasury Notes 3.5% 4/30/2030  | 3.73 | 30400000 | 30166063 |
| US Treasury Notes 3.5% 9/30/2029  | 3.56 | 39300000 | 39089684 |
| US Treasury Notes 3.625% 8/15/2028  | 3.58 | 17000000 | 17022578 |
| US Treasury Notes 3.625% 8/31/2027  | 3.61 | 26850000 | 26855244 |
| US Treasury Notes 3.625% 8/31/2029  | 3.71 | 66500700 | 66469528 |
| US Treasury Notes 3.625% 8/31/2030  | 3.69 | 87300000 | 87034008 |
| US Treasury Notes 3.75% 12/31/2028  | 3.85 to 3.91 | 11538500 | 11590333 |
| US Treasury Notes 3.75% 4/15/2028  | 3.58 to 3.87 | 40050000 | 40203316 |
| US Treasury Notes 3.75% 4/30/2027  | 3.59 to 3.81 | 29300000 | 29330902 |
| US Treasury Notes 3.75% 5/15/2028  | 3.70 to 3.85 | 26750000 | 26861061 |
| US Treasury Notes 3.75% 5/31/2030  | 3.98 | 29150000 | 29227430 |
| US Treasury Notes 3.75% 6/30/2027  | 3.72 | 24300000 | 24341766 |
| US Treasury Notes 3.75% 8/15/2027  | 3.76 to 4.12 | 22257500 | 22301841 |
| US Treasury Notes 3.75% 8/31/2026  | 3.93 | 47900 | 47842 |
| US Treasury Notes 3.875% 10/15/2027  | 3.81 | 24100000 | 24221441 |
| US Treasury Notes 3.875% 11/30/2027  | 3.61 to 4.03 | 53516800 | 53815742 |
| US Treasury Notes 3.875% 11/30/2029  | 4.10 | 9850000 | 9933879 |
| US Treasury Notes 3.875% 3/15/2028  | 3.57 to 3.88 | 26900000 | 27091242 |
| US Treasury Notes 3.875% 3/31/2027  | 3.89 | 21400000 | 21455172 |
| US Treasury Notes 3.875% 4/30/2030  | 3.72 to 3.92 | 22350000 | 22539451 |
| US Treasury Notes 3.875% 5/31/2027  | 3.89 | 5300000 | 5317805 |
| US Treasury Notes 3.875% 6/30/2030  | 3.79 | 43500000 | 43856836 |
| US Treasury Notes 3.875% 7/15/2028  | 3.89 | 13150000 | 13251707 |
| US Treasury Notes 3.875% 7/31/2027  | 3.94 | 22550000 | 22643371 |
| US Treasury Notes 3.875% 7/31/2030  | 3.95 | 42850000 | 43194809 |
| US Treasury Notes 4% 1/15/2027  | 4.18 | 13200000 | 13240734 |
| US Treasury Notes 4% 12/15/2027  | 4.05 | 15000000 | 15133352 |
| US Treasury Notes 4% 2/28/2030  | 4.00 | 66300000 | 67229754 |
| US Treasury Notes 4% 2/29/2028  | 4.04 | 3401700 | 3434388 |
| US Treasury Notes 4% 3/31/2030  | 3.95 | 42200000 | 42778602 |
| US Treasury Notes 4% 5/31/2030  | 3.95 | 45250000 | 45877490 |
| US Treasury Notes 4% 7/31/2029  | 3.64 to 4.10 | 63137200 | 63974904 |
| US Treasury Notes 4.125% 1/31/2027  | 4.20 | 29150000 | 29294611 |
| US Treasury Notes 4.125% 10/31/2026  | 4.16 to 4.20 | 30650000 | 30748176 |
| US Treasury Notes 4.125% 10/31/2027  | 4.24 | 6947100 | 7019556 |
| US Treasury Notes 4.125% 10/31/2029  | 4.15 | 40600000 | 41334289 |
| US Treasury Notes 4.125% 11/15/2027  | 4.02 | 20350000 | 20566219 |
| US Treasury Notes 4.125% 11/30/2029  | 4.08 | 44500000 | 45315254 |
| US Treasury Notes 4.125% 2/28/2027  | 3.99 | 18150000 | 18253512 |
| US Treasury Notes 4.125% 3/31/2029  | 4.21 | 1676900 | 1705394 |
| US Treasury Notes 4.125% 7/31/2028  | 3.94 | 12350000 | 12531391 |
| US Treasury Notes 4.125% 9/30/2027  | 3.44 | 1629000 | 1645417 |
| US Treasury Notes 4.25% 1/15/2028  | 4.24 | 12500000 | 12681152 |
| US Treasury Notes 4.25% 1/31/2030  | 4.33 | 39300000 | 40225699 |
| US Treasury Notes 4.25% 11/30/2026  | 4.15 | 31930000 | 32099628 |
| US Treasury Notes 4.25% 12/31/2026  | 3.87 | 29390000 | 29565651 |
| US Treasury Notes 4.25% 2/15/2028  | 3.96 | 21150000 | 21471780 |
| US Treasury Notes 4.25% 2/28/2029  | 4.12 | 9100000 | 9290176 |
| US Treasury Notes 4.25% 3/15/2027  | 4.26 | 34500000 | 34770879 |
| US Treasury Notes 4.25% 6/30/2029  | 4.35 | 48588000 | 49659642 |
| US Treasury Notes 4.375% 11/30/2028  | 4.29 | 91606200 | 93760378 |
| US Treasury Notes 4.375% 12/15/2026  | 4.01 to 4.19 | 17696100 | 17826056 |
| US Treasury Notes 4.375% 12/31/2029  | 4.39 | 36350000 | 37379443 |
| US Treasury Notes 4.375% 7/15/2027  | 4.07 | 7857400 | 7958914 |
| US Treasury Notes 4.375% 7/31/2026  | 3.91 | 5279800 | 5301455 |
| US Treasury Notes 4.375% 8/31/2028  | 4.25 | 90073100 | 92064561 |
| US Treasury Notes 4.5% 5/31/2029  | 3.68 to 4.50 | 40296900 | 41515252 |
| US Treasury Notes 4.625% 10/15/2026  | 4.90 | 15283700 | 15416238 |
| US Treasury Notes 4.625% 11/15/2026  | 4.02 | 1868500 | 1886090 |
| US Treasury Notes 4.625% 4/30/2029  | 4.09 | 3600000 | 3722906 |
| US Treasury Notes 4.625% 6/15/2027  | 3.80 | 2299700 | 2337340 |
| US Treasury Notes 4.625% 9/15/2026  | 4.06 to 4.90 | 49445100 | 49834316 |
| US Treasury Notes 4.625% 9/30/2028  | 4.04 | 20150000 | 20752139 |
| US Treasury Notes 4.875% 10/31/2028  | 4.83 | 38559600 | 40016129 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $3,217,812,341) |  |  | **3243595333** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 0.6%** | &nbsp;&nbsp;**Money Market Funds - 0.6%** | &nbsp;&nbsp;**Money Market Funds - 0.6%** | &nbsp;&nbsp;**Money Market Funds - 0.6%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $19,774,789)<br>| 4.36 | 19770834 | **19774789** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 99.9%**<br> (Cost $3,237,587,130)<br>| <br>**3263370122** |
| **NET OTHER ASSETS (LIABILITIES) - 0.1%**  | **3020085** |
| **NET ASSETS - 100.0%** | **3266390207** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 27280209 | 334963004 | 342468424 | 396427 | - | - | 19774789 | 19770834 | 0.0% |
| Fidelity Securities Lending Cash Central Fund | - | 192001739 | 192001739 | 13085 | - | - | - | - | 0.0% |
| Total | 27280209 | 526964743 | 534470163 | 409512 | - | - | 19774789 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts in the dividend income column for Fidelity Securities Lending Cash Central Fund represents the income earned on investing cash collateral, less rebates paid to borrowers and any lending agent fees associated with the loan, plus any premium income received for lending certain types of securities.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 3243595333 | - | 3243595333 | - |
|  **Money Market Funds** | 19774789 | 19774789 | - | - |
| **Total Investments in Securities:** | 3263370122 | 19774789 | 3243595333 | - |

---

**Fidelity® Short-Term Treasury Bond Index Fund**

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $3,217,812,341) | $3243595333 |  |
| Fidelity Central Funds (cost $19,774,789) | 19774789 |  |
| Total Investment in Securities (cost $3,237,587,130) |  | $3263370122 |
| Receivable for investments sold |  | 108911366 |
| Receivable for fund shares sold |  | 2621399 |
| Interest receivable |  | 27777028 |
| Distributions receivable from Fidelity Central Funds |  | 69637 |
| **Total assets** |  | 3402749552 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $132380178 |  |
| Payable for fund shares redeemed | 1753286 |  |
| Distributions payable | 2145109 |  |
| Accrued management fee | 80772 |  |
| **Total liabilities** |  | 136359345 |
| **Net Assets**  |  | $3266390207 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $3334545615 |
| Total accumulated earnings (loss) |  | (68155408) |
| **Net Assets** |  | $3266390207 |
| **Net Asset Value**, offering price and redemption price per share ($3,266,390,207 ÷ 313,716,675 shares) |  | $10.41 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $59976836 |
| Income from Fidelity Central Funds (including $13,085 from security lending)  |  | 409512 |
| **Total income** |  | 60386348 |
| **Expenses** |  |  |
| Management fee | $473444 |  |
| Independent trustees' fees and expenses | 3587 |  |
| Total expenses before reductions | 477031 |  |
| Expense reductions | (4) |  |
| Total expenses after reductions |  | 477027 |
| **Net Investment income (loss)** |  | 59909321 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (3287465) |  |
| Total net realized gain (loss) |  | (3287465) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | 31323810 |
| **Net gain (loss)** |  | 28036345 |
| **Net increase (decrease) in net assets resulting from operations** |  | $87945666 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **Year ended**<br> **February 28, 2025** |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $59909321 | $113771722 |
| &nbsp;&nbsp;Net realized gain (loss) | (3287465)<br>| (18971689)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | 31323810 | 74367743<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | 87945666<br>| 169167776<br>|
| Distributions to shareholders | (43081037)<br>| (93546280)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 697056585 | 920719775 |
| Reinvestment of distributions | 31467413<br>| 69530895<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (509759453) | (1534056186) |
| **Net increase (decrease) in net assets resulting from share transactions** | 218764545<br>| (543805516)<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 263629174<br>| (468184020)<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 3002761033 | 3470945053<br>|
| &nbsp;&nbsp;End of period | $3266390207 | $3002761033 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 67582882 | 90213606 |
| Issued in reinvestment of distributions | 3040124<br>| 6836781<br>|
| &nbsp;&nbsp;Redeemed | (49439825) | (150126100) |
| &nbsp;&nbsp;Net increase (decrease) | 21183181 | (53075713) |

---

**Financial Highlights** 

**Fidelity® Short-Term Treasury Bond Index Fund** <br>

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025**  | **2024** A  | **2023**  | **2022**  | **2021**  |
| **Selected Per-Share Data**  |  |  |  |  |  |  |
| Net asset value, beginning of period  | $10.26 | $10.04 | $9.82 | $10.38 | $10.76 | $10.72 |
| Income from Investment Operations  |  |  |  |  |  |  |
| Net investment income (loss) B,C | .196  | .364  | .300  | .164  | .087  | .127  |
| Net realized and unrealized gain (loss)  | .095  | .162  | .094  | (.606)  | (.333)  | .068  |
| Total from investment operations  | .291  | .526  | .394  | (.442)  | (.246)  | .195  |
| Distributions from net investment income  | (.141)  | (.306)  | (.174)  | (.118)  | (.086)  | (.125)  |
| Distributions from net realized gain  | -  | -  | -  | -  | (.048)  | (.030)  |
| Total distributions  | (.141)  | (.306)  | (.174)  | (.118)  | (.134)  | (.155)  |
| Net asset value, end of period  | $10.41 | $10.26 | $10.04 | $9.82 | $10.38 | $10.76 |
| **Total Return** D,E | 2.85% <br>| 5.31%  | 4.03%  | (4.26)%  | (2.31)%  | 1.82%  |
| **Ratios to Average Net Assets** C,F,G |  |  |  |  |  |  |
| Expenses before reductions  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of fee waivers, if any  | .03% H<br>| .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of all reductions, if any  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Net investment income (loss)  | 3.77% H | 3.58%  | 3.01%  | 1.65%  | .82%  | 1.17%  |
| **Supplemental Data** |  |  |  |  |  |  |
| Net assets, end of period (000 omitted) | $3266390 | $3002761 | $3470945 | $4261248 | $3911330 | $3870957 |
| Portfolio turnover rate I | 32% H<br>| 42% J | 69%  | 60%  | 48%  | 54%  |

---

A*For the year ended February 29.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*Total returns for periods of less than one year are not annualized.*

E*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

F*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

G*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

H*Annualized.*

I*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

J*Portfolio turnover rate excludes securities received or delivered in-kind.*

**Fidelity® Intermediate Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 6.25% 5/15/2030  | 4.14 | 12124600 | 13453569 |
| US Treasury Notes 0.625% 5/15/2030  | 3.96 | 7176800 | 6236807 |
| US Treasury Notes 0.625% 8/15/2030  | 0.85 to 4.05 | 43937300 | 37863311 |
| US Treasury Notes 0.875% 11/15/2030  | 1.48 to 3.80 | 303206900 | 262818795 |
| US Treasury Notes 1.25% 8/15/2031  | 1.31 to 4.37 | 413931600 | 357678941 |
| US Treasury Notes 1.375% 11/15/2031  | 1.44 to 3.86 | 257080400 | 222143575 |
| US Treasury Notes 1.625% 5/15/2031  | 1.44 to 4.41 | 173175100 | 154146133 |
| US Treasury Notes 1.875% 2/15/2032  | 2.33 to 4.08 | 210324000 | 186330638 |
| US Treasury Notes 2.75% 8/15/2032  | 3.53 to 4.27 | 207686200 | 192831769 |
| US Treasury Notes 2.875% 5/15/2032  | 2.86 to 4.45 | 293900100 | 276059447 |
| US Treasury Notes 3.375% 5/15/2033  | 3.96 to 4.41 | 210438300 | 201700178 |
| US Treasury Notes 3.5% 2/15/2033  | 3.48 to 4.21 | 247961300 | 240348114 |
| US Treasury Notes 3.625% 9/30/2031  | 3.66 | 75250000 | 74403438 |
| US Treasury Notes 3.75% 8/31/2031  | 3.95 | 19080000 | 19004723 |
| US Treasury Notes 3.875% 8/15/2033  | 4.22 to 4.91 | 225594600 | 223232907 |
| US Treasury Notes 3.875% 8/15/2034  | 3.79 to 4.65 | 221200600 | 216880287 |
| US Treasury Notes 4% 1/31/2031  | 3.94 to 4.19 | 173388700 | 175447691 |
| US Treasury Notes 4% 2/15/2034  | 4.19 to 4.69 | 283677800 | 282015624 |
| US Treasury Notes 4% 4/30/2032  | 3.93 to 4.16 | 103600000 | 104198938 |
| US Treasury Notes 4% 6/30/2032  | 3.99 | 70250000 | 70612227 |
| US Treasury Notes 4% 7/31/2032  | 3.92 to 4.14 | 225350000 | 226371117 |
| US Treasury Notes 4.125% 10/31/2031  | 4.13 to 4.22 | 130300000 | 132290129 |
| US Treasury Notes 4.125% 11/15/2032  | 3.64 to 3.87 | 174721100 | 176673063 |
| US Treasury Notes 4.125% 11/30/2031  | 4.01 to 4.49 | 65050000 | 66015586 |
| US Treasury Notes 4.125% 2/29/2032  | 4.10 to 4.21 | 111350000 | 112894112 |
| US Treasury Notes 4.125% 3/31/2031  | 3.96 to 4.39 | 250932400 | 255362925 |
| US Treasury Notes 4.125% 3/31/2032  | 4.08 to 4.15 | 117150000 | 118728779 |
| US Treasury Notes 4.125% 5/31/2032  | 3.99 | 33900000 | 34327347 |
| US Treasury Notes 4.125% 7/31/2031  | 3.81 to 3.97 | 81383800 | 82717762 |
| US Treasury Notes 4.125% 8/31/2030  | 4.33 to 4.47 | 39661700 | 40406906 |
| US Treasury Notes 4.25% 11/15/2034  | 4.19 to 4.58 | 308550000 | 310574859 |
| US Treasury Notes 4.25% 2/28/2031  | 4.27 | 142171700 | 145598260 |
| US Treasury Notes 4.25% 5/15/2035  | 4.23 to 4.39 | 244450000 | 245213906 |
| US Treasury Notes 4.25% 6/30/2031  | 3.64 to 4.53 | 61800000 | 63226711 |
| US Treasury Notes 4.25% 8/15/2035  | 4.22 | 89800000 | 89982406 |
| US Treasury Notes 4.375% 1/31/2032  | 4.36 to 4.44 | 89900000 | 92414391 |
| US Treasury Notes 4.375% 11/30/2030  | 3.87 to 4.32 | 70414700 | 72540894 |
| US Treasury Notes 4.375% 5/15/2034  | 4.05 to 4.49 | 269190300 | 274447923 |
| US Treasury Notes 4.5% 11/15/2033  | 3.86 to 4.34 | 239572600 | 247040528 |
| US Treasury Notes 4.5% 12/31/2031  | 4.49 to 4.55 | 130300000 | 134911398 |
| US Treasury Notes 4.625% 2/15/2035  | 4.16 to 4.35 | 276310000 | 285764997 |
| US Treasury Notes 4.625% 4/30/2031  | 4.03 to 4.71 | 79742200 | 83134358 |
| US Treasury Notes 4.625% 5/31/2031  | 4.13 to 4.51 | 48458100 | 50511890 |
| US Treasury Notes 4.875% 10/31/2030  | 4.08 to 4.36 | 113827600 | 119910262 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $6,790,537,996) |  |  | **6778467621** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 0.7%** | &nbsp;&nbsp;**Money Market Funds - 0.7%** | &nbsp;&nbsp;**Money Market Funds - 0.7%** | &nbsp;&nbsp;**Money Market Funds - 0.7%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $49,092,530)<br>| 4.36 | 49082713 | **49092530** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 100.0%**<br> (Cost $6,839,630,526)<br>| <br>**6827560151** |
| **NET OTHER ASSETS (LIABILITIES) - 0.0%**  | **(2689369)** |
| **NET ASSETS - 100.0%** | **6824870782** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 74183267 | 530727133 | 555817870 | 495522 | - | - | 49092530 | 49082713 | 0.1% |
| Fidelity Securities Lending Cash Central Fund | - | 405660736 | 405660736 | 9072 | - | - | - | - | 0.0% |
| Total | 74183267 | 936387869 | 961478606 | 504594 | - | - | 49092530 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts in the dividend income column for Fidelity Securities Lending Cash Central Fund represents the income earned on investing cash collateral, less rebates paid to borrowers and any lending agent fees associated with the loan, plus any premium income received for lending certain types of securities.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 6778467621 | - | 6778467621 | - |
|  **Money Market Funds** | 49092530 | 49092530 | - | - |
| **Total Investments in Securities:** | 6827560151 | 49092530 | 6778467621 | - |

---

**Fidelity® Intermediate Treasury Bond Index Fund**

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $6,790,537,996) | $6778467621 |  |
| Fidelity Central Funds (cost $49,092,530) | 49092530 |  |
| Total Investment in Securities (cost $6,839,630,526) |  | $6827560151 |
| Receivable for investments sold |  | 256971660 |
| Receivable for fund shares sold |  | 5961678 |
| Interest receivable |  | 52783172 |
| Distributions receivable from Fidelity Central Funds |  | 108704 |
| **Total assets** |  | 7143385365 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $308375836 |  |
| Payable for fund shares redeemed | 5999909 |  |
| Distributions payable | 3970069 |  |
| Accrued management fee | 168769 |  |
| **Total liabilities** |  | 318514583 |
| **Net Assets**  |  | $6824870782 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $7334494316 |
| Total accumulated earnings (loss) |  | (509623534) |
| **Net Assets** |  | $6824870782 |
| **Net Asset Value**, offering price and redemption price per share ($6,824,870,782 ÷ 692,782,814 shares) |  | $9.85 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $126690047 |
| Income from Fidelity Central Funds (including $9,072 from security lending)  |  | 504594 |
| **Total income** |  | 127194641 |
| **Expenses** |  |  |
| Management fee | $984034 |  |
| Independent trustees' fees and expenses | 7526 |  |
| Total expenses before reductions | 991560 |  |
| Expense reductions | (6) |  |
| Total expenses after reductions |  | 991554 |
| **Net Investment income (loss)** |  | 126203087 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (46966716) |  |
| Total net realized gain (loss) |  | (46966716) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | 133853092 |
| **Net gain (loss)** |  | 86886376 |
| **Net increase (decrease) in net assets resulting from operations** |  | $213089463 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **Year ended**<br> **February 28, 2025** |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $126203087 | $284893647 |
| &nbsp;&nbsp;Net realized gain (loss) | (46966716)<br>| (986960)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | 133853092 | 200055303<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | 213089463<br>| 483961990<br>|
| Distributions to shareholders | (109130966)<br>| (266866008)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 1254630539 | 2692553523 |
| Reinvestment of distributions | 87703087<br>| 221516656<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (1260893172) | (4639611472) |
| **Net increase (decrease) in net assets resulting from share transactions** | 81440454<br>| (1725541293)<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 185398951<br>| (1508445311)<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 6639471831 | 8147917142<br>|
| &nbsp;&nbsp;End of period | $6824870782 | $6639471831 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 129165514 | 280083625 |
| Issued in reinvestment of distributions | 8983791<br>| 23088333<br>|
| &nbsp;&nbsp;Redeemed | (130043762) | (471959286) |
| &nbsp;&nbsp;Net increase (decrease) | 8105543 | (168787328) |

---

**Financial Highlights** 

**Fidelity® Intermediate Treasury Bond Index Fund** <br>

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025**  | **2024** A  | **2023**  | **2022**  | **2021**  |
| **Selected Per-Share Data**  |  |  |  |  |  |  |
| Net asset value, beginning of period  | $9.70 | $9.55 | $9.55 | $10.87 | $11.38 | $11.65 |
| Income from Investment Operations  |  |  |  |  |  |  |
| Net investment income (loss) B,C | .187  | .358  | .315  | .196  | .151  | .174  |
| Net realized and unrealized gain (loss)  | .125  | .137  | (.089)  | (1.352)  | (.443)  | (.092)  |
| Total from investment operations  | .312  | .495  | .226  | (1.156)  | (.292)  | .082  |
| Distributions from net investment income  | (.162)  | (.345)  | (.226)  | (.164)  | (.148)  | (.171)  |
| Distributions from net realized gain  | -  | -  | -  | -  | (.070)  | (.181)  |
| Total distributions  | (.162)  | (.345)  | (.226)  | (.164)  | (.218)  | (.352)  |
| Net asset value, end of period  | $9.85 | $9.70 | $9.55 | $9.55 | $10.87 | $11.38 |
| **Total Return** D,E | 3.24% <br>| 5.29%  | 2.39%  | (10.67)%  | (2.60)%  | .63%  |
| **Ratios to Average Net Assets** C,F,G |  |  |  |  |  |  |
| Expenses before reductions  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of fee waivers, if any  | .03% H<br>| .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of all reductions, if any  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Net investment income (loss)  | 3.82% H | 3.72%  | 3.30%  | 1.97%  | 1.35%  | 1.46%  |
| **Supplemental Data** |  |  |  |  |  |  |
| Net assets, end of period (000 omitted) | $6824871 | $6639472 | $8147917 | $5642498 | $4396511 | $4571767 |
| Portfolio turnover rate I | 45% H<br>| 47% J | 48%  | 41%  | 54%  | 56%  |

---

A*For the year ended February 29.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*Total returns for periods of less than one year are not annualized.*

E*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

F*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

G*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

H*Annualized.*

I*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

J*Portfolio turnover rate excludes securities received or delivered in-kind.*

**Fidelity® Long-Term Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.3%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 1.125% 5/15/2040  | 4.52 to 4.93 | 21709000 | 13509613 |
| US Treasury Bonds 1.125% 8/15/2040  | 1.74 to 4.57 | 57054000 | 35123869 |
| US Treasury Bonds 1.25% 5/15/2050  | 4.89 | 12900000 | 6078620 |
| US Treasury Bonds 1.375% 11/15/2040  | 1.37 to 4.86 | 102088000 | 65061161 |
| US Treasury Bonds 1.375% 8/15/2050  | 1.46 to 5.03 | 212495000 | 102661647 |
| US Treasury Bonds 1.625% 11/15/2050  | 1.84 to 5.07 | 130631000 | 67397432 |
| US Treasury Bonds 1.75% 8/15/2041  | 1.96 to 4.15 | 87455000 | 57932106 |
| US Treasury Bonds 1.875% 11/15/2051  | 1.78 to 5.11 | 248250000 | 135102305 |
| US Treasury Bonds 1.875% 2/15/2041  | 2.03 to 4.14 | 141748000 | 97412990 |
| US Treasury Bonds 1.875% 2/15/2051  | 2.23 to 5.06 | 185960000 | 102299793 |
| US Treasury Bonds 2% 11/15/2041  | 1.94 to 4.66 | 77050000 | 52830416 |
| US Treasury Bonds 2% 2/15/2050  | 1.68 to 5.17 | 79766900 | 46046689 |
| US Treasury Bonds 2% 8/15/2051  | 1.93 to 4.99 | 104604000 | 59035883 |
| US Treasury Bonds 2.25% 2/15/2052  | 2.16 to 5.18 | 171450000 | 102488256 |
| US Treasury Bonds 2.25% 5/15/2041  | 1.96 to 4.86 | 102827000 | 74513425 |
| US Treasury Bonds 2.25% 8/15/2046  | 4.89 to 5.11 | 52963000 | 34314231 |
| US Treasury Bonds 2.25% 8/15/2049  | 1.94 to 4.46 | 25759000 | 15896121 |
| US Treasury Bonds 2.375% 11/15/2049  | 2.90 to 4.73 | 23745000 | 15027988 |
| US Treasury Bonds 2.375% 2/15/2042  | 2.24 to 5.20 | 79900000 | 57780268 |
| US Treasury Bonds 2.375% 5/15/2051  | 1.92 to 5.13 | 118397000 | 73568011 |
| US Treasury Bonds 2.5% 2/15/2045  | 3.16 to 4.70 | 29414000 | 20493285 |
| US Treasury Bonds 2.5% 2/15/2046  | 3.35 to 4.87 | 11773000 | 8073242 |
| US Treasury Bonds 2.5% 5/15/2046  | 3.13 to 4.12 | 41212000 | 28175486 |
| US Treasury Bonds 2.75% 11/15/2042  | 3.15 to 4.05 | 30225000 | 22844669 |
| US Treasury Bonds 2.75% 11/15/2047  | 3.08 to 4.92 | 25375000 | 17818999 |
| US Treasury Bonds 2.75% 8/15/2042  | 3.61 to 4.19 | 7787000 | 5915686 |
| US Treasury Bonds 2.75% 8/15/2047  | 3.14 to 3.39 | 21492000 | 15137588 |
| US Treasury Bonds 2.875% 11/15/2046  | 1.83 to 4.26 | 72529000 | 52810178 |
| US Treasury Bonds 2.875% 5/15/2043  | 3.37 to 4.91 | 92418000 | 70678109 |
| US Treasury Bonds 2.875% 5/15/2049  | 2.58 to 4.47 | 52790000 | 37330366 |
| US Treasury Bonds 2.875% 5/15/2052  | 3.15 to 5.05 | 152750000 | 105331865 |
| US Treasury Bonds 2.875% 8/15/2045  | 2.94 to 5.08 | 67587500 | 49980428 |
| US Treasury Bonds 3% 11/15/2044  | 2.91 to 4.56 | 65587000 | 50038270 |
| US Treasury Bonds 3% 11/15/2045  | 3.08 to 4.99 | 62732000 | 47303849 |
| US Treasury Bonds 3% 2/15/2047  | 2.97 to 5.09 | 40390000 | 30002197 |
| US Treasury Bonds 3% 2/15/2048  | 1.36 to 4.55 | 77947000 | 57178387 |
| US Treasury Bonds 3% 2/15/2049  | 4.46 to 4.88 | 43250000 | 31415381 |
| US Treasury Bonds 3% 5/15/2042  | 1.67 to 5.31 | 57501000 | 45609973 |
| US Treasury Bonds 3% 5/15/2045  | 1.83 to 4.76 | 73664000 | 55846520 |
| US Treasury Bonds 3% 5/15/2047  | 3.17 to 3.84 | 11507000 | 8521022 |
| US Treasury Bonds 3% 8/15/2048  | 2.01 to 4.95 | 105591000 | 77056682 |
| US Treasury Bonds 3% 8/15/2052  | 3.76 to 4.98 | 115000000 | 81326563 |
| US Treasury Bonds 3.125% 11/15/2041  | 2.11 to 4.20 | 64820000 | 52840960 |
| US Treasury Bonds 3.125% 2/15/2042  | 4.06 to 5.30 | 106856000 | 86666060 |
| US Treasury Bonds 3.125% 2/15/2043  | 2.30 to 4.13 | 47347000 | 37761082 |
| US Treasury Bonds 3.125% 5/15/2048  | 1.93 to 3.43 | 88953000 | 66607033 |
| US Treasury Bonds 3.125% 8/15/2044  | 3.31 to 4.94 | 36284300 | 28355614 |
| US Treasury Bonds 3.25% 5/15/2042  | 3.98 to 5.22 | 140700000 | 115698270 |
| US Treasury Bonds 3.375% 11/15/2048  | 3.07 to 4.58 | 64444000 | 50288976 |
| US Treasury Bonds 3.375% 5/15/2044  | 3.36 to 4.56 | 22229300 | 18112538 |
| US Treasury Bonds 3.375% 8/15/2042  | 3.79 to 4.41 | 34950000 | 29150484 |
| US Treasury Bonds 3.625% 2/15/2044  | 1.76 to 5.18 | 73325000 | 62194494 |
| US Treasury Bonds 3.625% 2/15/2053  | 3.64 to 5.03 | 91600000 | 73319360 |
| US Treasury Bonds 3.625% 5/15/2053  | 3.81 to 4.71 | 109600000 | 87632906 |
| US Treasury Bonds 3.625% 8/15/2043  | 2.29 to 4.80 | 105903000 | 90323675 |
| US Treasury Bonds 3.75% 11/15/2043  | 2.96 to 4.43 | 80368000 | 69584247 |
| US Treasury Bonds 3.75% 8/15/2041  | 2.11 to 5.02 | 95131000 | 84785504 |
| US Treasury Bonds 3.875% 2/15/2043  | 3.84 to 4.64 | 23050000 | 20481186 |
| US Treasury Bonds 3.875% 5/15/2043  | 4.88 to 5.11 | 76700000 | 67955901 |
| US Treasury Bonds 4% 11/15/2042  | 4.47 to 5.21 | 55250000 | 50050889 |
| US Treasury Bonds 4% 11/15/2052  | 3.93 to 5.00 | 101200000 | 86850156 |
| US Treasury Bonds 4.125% 8/15/2044  | 4.11 to 5.03 | 65650000 | 59636358 |
| US Treasury Bonds 4.125% 8/15/2053  | 4.20 to 5.07 | 148100000 | 129708988 |
| US Treasury Bonds 4.25% 11/15/2040  | 3.95 to 4.87 | 11899000 | 11353319 |
| US Treasury Bonds 4.25% 2/15/2054  | 4.34 to 4.95 | 104400000 | 93405375 |
| US Treasury Bonds 4.25% 5/15/2039  | 4.32 to 5.05 | 22331000 | 21686367 |
| US Treasury Bonds 4.25% 8/15/2054  | 3.96 to 4.48 | 128050000 | 114564734 |
| US Treasury Bonds 4.375% 11/15/2039  | 4.56 | 3250000 | 3174716 |
| US Treasury Bonds 4.375% 2/15/2038  | 3.70 to 4.64 | 24500000 | 24436836 |
| US Treasury Bonds 4.375% 5/15/2041  | 3.07 to 5.16 | 60103000 | 57940701 |
| US Treasury Bonds 4.375% 8/15/2043  | 4.16 to 5.26 | 106200000 | 100417079 |
| US Treasury Bonds 4.5% 11/15/2054  | 4.37 to 4.85 | 99750000 | 93114287 |
| US Treasury Bonds 4.5% 2/15/2036  | 4.15 to 5.29 | 4765000 | 4887102 |
| US Treasury Bonds 4.5% 2/15/2044  | 4.39 to 4.93 | 86800000 | 83199156 |
| US Treasury Bonds 4.5% 5/15/2038  | 4.38 to 4.64 | 17160000 | 17336963 |
| US Treasury Bonds 4.5% 8/15/2039  | 4.19 to 4.69 | 4033000 | 4004327 |
| US Treasury Bonds 4.625% 11/15/2044  | 4.49 to 4.95 | 64750000 | 62812558 |
| US Treasury Bonds 4.625% 2/15/2040  | 4.55 | 9750000 | 9765996 |
| US Treasury Bonds 4.625% 2/15/2055  | 4.47 to 4.88 | 103200000 | 98362500 |
| US Treasury Bonds 4.625% 5/15/2044  | 4.56 to 4.93 | 45250000 | 44016231 |
| US Treasury Bonds 4.625% 5/15/2054  | 4.06 to 4.81 | 134500000 | 128137519 |
| US Treasury Bonds 4.75% 11/15/2043  | 4.20 to 4.92 | 81000000 | 80250117 |
| US Treasury Bonds 4.75% 11/15/2053  | 4.00 to 5.01 | 124350000 | 120881801 |
| US Treasury Bonds 4.75% 2/15/2037  | 3.36 to 4.84 | 35578000 | 37019187 |
| US Treasury Bonds 4.75% 5/15/2055  | 4.79 to 5.01 | 101800000 | 99032313 |
| US Treasury Bonds 4.75% 8/15/2045  | 4.74 | 13350000 | 13364602 |
| US Treasury Bonds 4.75% 8/15/2055  | 4.91 to 4.92 | 47850000 | 46564031 |
| US Treasury Bonds 5% 5/15/2037  | 1.64 to 4.70 | 10019000 | 10645188 |
| US Treasury Bonds 5% 5/15/2045  | 4.79 to 4.93 | 58950000 | 59935570 |
| US Treasury Notes 4.75% 2/15/2045  | 4.52 to 4.71 | 36850000 | 36303008 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $5,804,293,992) |  |  | **4977585833** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 0.9%** | &nbsp;&nbsp;**Money Market Funds - 0.9%** | &nbsp;&nbsp;**Money Market Funds - 0.9%** | &nbsp;&nbsp;**Money Market Funds - 0.9%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $46,433,544)<br>| 4.36 | 46424259 | **46433544** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 100.2%**<br> (Cost $5,850,727,536)<br>| <br>**5024019377** |
| **NET OTHER ASSETS (LIABILITIES) - (0.2)%**  | **(8090375)** |
| **NET ASSETS - 100.0%** | **5015929002** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 47593706 | 470051713 | 471211875 | 311949 | - | - | 46433544 | 46424259 | 0.1% |
| Fidelity Securities Lending Cash Central Fund | 10475000 | 82406082 | 92881082 | 7739 | - | - | - | - | 0.0% |
| Total | 58068706 | 552457795 | 564092957 | 319688 | - | - | 46433544 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts in the dividend income column for Fidelity Securities Lending Cash Central Fund represents the income earned on investing cash collateral, less rebates paid to borrowers and any lending agent fees associated with the loan, plus any premium income received for lending certain types of securities.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 4977585833 | - | 4977585833 | - |
|  **Money Market Funds** | 46433544 | 46433544 | - | - |
| **Total Investments in Securities:** | 5024019377 | 46433544 | 4977585833 | - |

---

**Fidelity® Long-Term Treasury Bond Index Fund**

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $5,804,293,992) | $4977585833 |  |
| Fidelity Central Funds (cost $46,433,544) | 46433544 |  |
| Total Investment in Securities (cost $5,850,727,536) |  | $5024019377 |
| Receivable for investments sold |  | 29041150 |
| Receivable for fund shares sold |  | 14413700 |
| Interest receivable |  | 35669025 |
| Distributions receivable from Fidelity Central Funds |  | 110797 |
| **Total assets** |  | 5103254049 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $56775031 |  |
| Payable for fund shares redeemed | 29581915 |  |
| Distributions payable | 842774 |  |
| Accrued management fee | 125327 |  |
| **Total liabilities** |  | 87325047 |
| **Net Assets**  |  | $5015929002 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $6525730649 |
| Total accumulated earnings (loss) |  | (1509801647) |
| **Net Assets** |  | $5015929002 |
| **Net Asset Value**, offering price and redemption price per share ($5,015,929,002 ÷ 547,083,414 shares) |  | $9.17 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $105451385 |
| Income from Fidelity Central Funds (including $7,739 from security lending)  |  | 319688 |
| **Total income** |  | 105771073 |
| **Expenses** |  |  |
| Management fee | $726974 |  |
| Independent trustees' fees and expenses | 5531 |  |
| Total expenses before reductions | 732505 |  |
| Expense reductions | (211) |  |
| Total expenses after reductions |  | 732294 |
| **Net Investment income (loss)** |  | 105038779 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (113384412) |  |
| Total net realized gain (loss) |  | (113384412) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | (131174736) |
| **Net gain (loss)** |  | (244559148) |
| **Net increase (decrease) in net assets resulting from operations** |  | $(139520369) |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **Year ended**<br> **February 28, 2025** |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $105038779 | $175590750 |
| &nbsp;&nbsp;Net realized gain (loss) | (113384412)<br>| (180631684)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | (131174736) | 149785402<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | (139520369)<br>| 144744468<br>|
| Distributions to shareholders | (95424906)<br>| (159694425)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 1295697367 | 2116499278 |
| Reinvestment of distributions | 90465253<br>| 150458182<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (951882308) | (1518115465) |
| **Net increase (decrease) in net assets resulting from share transactions** | 434280312<br>| 748841995<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 199335037<br>| 733892038<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 4816593965 | 4082701927<br>|
| &nbsp;&nbsp;End of period | $5015929002 | $4816593965 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 140605025 | 220716563 |
| Issued in reinvestment of distributions | 9766532<br>| 15728153<br>|
| &nbsp;&nbsp;Redeemed | (102869752) | (159357487) |
| &nbsp;&nbsp;Net increase (decrease) | 47501805 | 77087229 |

---

**Financial Highlights** 

**Fidelity® Long-Term Treasury Bond Index Fund** <br>

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025**  | **2024** A  | **2023**  | **2022**  | **2021**  |
| **Selected Per-Share Data**  |  |  |  |  |  |  |
| Net asset value, beginning of period  | $9.64 | $9.66 | $10.29 | $13.94 | $14.49 | $16.10 |
| Income from Investment Operations  |  |  |  |  |  |  |
| Net investment income (loss) B,C | .200  | .382  | .357  | .320  | .310  | .336  |
| Net realized and unrealized gain (loss)  | (.488)  | (.055)  | (.659)  | (3.663)  | (.448)  | (1.296)  |
| Total from investment operations  | (.288)  | .327  | (.302)  | (3.343)  | (.138)  | (.960)  |
| Distributions from net investment income  | (.182)  | (.347)  | (.328)  | (.307)  | (.301)  | (.330)  |
| Distributions from net realized gain  | -  | -  | -  | -  | (.111)  | (.320)  |
| Total distributions  | (.182)  | (.347)  | (.328)  | (.307)  | (.412)  | (.650)  |
| Net asset value, end of period  | $9.17 | $9.64 | $9.66 | $10.29 | $13.94 | $14.49 |
| **Total Return** D,E | (2.99)% <br>| 3.48%  | (2.96)%  | (24.10)%  | (1.02)%  | (6.32)%  |
| **Ratios to Average Net Assets** C,F,G |  |  |  |  |  |  |
| Expenses before reductions  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of fee waivers, if any  | .03% H<br>| .03%  | .03%  | .03%  | .03%  | .03%  |
| Expenses net of all reductions, if any  | .03% H | .03%  | .03%  | .03%  | .03%  | .03%  |
| Net investment income (loss)  | 4.31% H | 3.99%  | 3.61%  | 2.85%  | 2.15%  | 2.04%  |
| **Supplemental Data** |  |  |  |  |  |  |
| Net assets, end of period (000 omitted) | $5015929 | $4816594 | $4082702 | $3203287 | $3858260 | $3011856 |
| Portfolio turnover rate I | 21% H<br>| 18%  | 17%  | 26%  | 22%  | 41%  |

---

A*For the year ended February 29.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*Total returns for periods of less than one year are not annualized.*

E*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

F*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

G*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

H*Annualized.*

I*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

**Notes to Financial Statements** **(Unaudited)**

For the period ended August 31, 2025

**1. Organization.**

Fidelity Short-Term Treasury Bond Index Fund, Fidelity Intermediate Treasury Bond Index Fund and Fidelity Long-Term Treasury Bond Index Fund (the Funds) are funds of Fidelity Salem Street Trust (the Trust). Each Fund is authorized to issue an unlimited number of shares. Share transactions on the Statement of Changes in Net Assets may contain exchanges between affiliated funds. 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.

**2. Investments in Fidelity Central Funds.**

Funds may invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Schedule of Investments lists any Fidelity Central Funds held as an investment as of period end, but does not include the underlying holdings of each Fidelity Central Fund. An investing fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

Based on its investment objective, each Fidelity Central Fund may invest or participate in various investment vehicles or strategies that are similar to those of the investing fund. These strategies are consistent with the investment objectives of the investing fund and may involve certain economic risks which may cause a decline in value of each of the Fidelity Central Funds and thus a decline in the value of the investing fund.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fidelity Central Fund** | **Investment Manager** | **Investment Objective** | **Investment Practices** | **Expense RatioA** |
| Fidelity Money Market Central Funds | Fidelity Management & Research Company LLC (FMR) | Each fund seeks to obtain a high level of current income consistent with the preservation of capital and liquidity. | Short-term Investments | Less than .005% |

---

*A Expenses expressed as a percentage of average net assets and are as of each underlying Central Fund's most recent annual or semi-annual shareholder report.* 

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds which contain the significant accounting policies (including investment valuation policies) of those funds, and are not covered by the Report of Independent Registered Public Accounting Firm, are available on the Securities and Exchange Commission website or upon request.

**3. Significant Accounting Policies.**

Each Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 *Financial Services - Investment Companies*. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. Each Fund operates as a single operating segment. Each Fund's income, expenses, assets, and performance are regularly monitored and assessed as a whole by the investment adviser and other individuals responsible for oversight functions of the Trust, using the information presented in the financial statements and financial highlights. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. Each Fund's Schedule of Investments lists any underlying mutual funds or exchange-traded funds but does not include the underlying holdings of these funds. The following summarizes the significant accounting policies of each Fund:

**Investment Valuation.** Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has designated each Fund's investment adviser as the valuation designee responsible for the fair valuation function and performing fair value determinations as needed. The investment adviser has established a Fair Value Committee (the Committee) to carry out the day-to-day fair valuation responsibilities and has adopted policies and procedures to govern the fair valuation process and the activities of the Committee. In accordance with these fair valuation policies and procedures, which have been approved by the Board, each Fund attempts to obtain prices from one or more third party pricing services or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with the policies and procedures. Factors used in determining fair value vary by investment type and may include market or investment specific events, transaction data, estimated cash flows, and market observations of comparable investments. The frequency that the fair valuation procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee manages each Fund's fair valuation practices and maintains the fair valuation policies and procedures. Each Fund's investment adviser reports to the Board information regarding the fair valuation process and related material matters.

Each Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value each Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing services or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing services who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing services. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of August 31, 2025 is included at the end of each Fund's Schedule of Investments.

**Investment Transactions and Income.** For financial reporting purposes, the Funds' investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

**Expenses.** Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

**Income Tax Information and Distributions to Shareholders.** Each year, each Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. Each Fund files a U.S. federal tax return, in addition to state and local tax returns as required. Each Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount, redemptions in kind, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows for each Fund:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Tax cost ($)**  | **Gross unrealized appreciation ($)** | **Gross unrealized depreciation ($)** | **Net unrealized appreciation (depreciation)($)** |
| **Fidelity Short-Term Treasury Bond Index Fund**  | 3175750600 | 94154216 | (6534694) | 87619522 |
| **Fidelity Intermediate Treasury Bond Index Fund**  | 6783089843 | 116378776 | (71908468) | 44470308 |
| **Fidelity Long-Term Treasury Bond Index Fund**  | 5874372492 | 14184241 | (864537356) | (850353115) |

---

Capital loss carryforwards are only available to offset future capital gains of the Funds to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of prior fiscal period end and is subject to adjustment.

---

| | | | |
|:---|:---|:---|:---|
|  | **Short-term ($)** | **Long-term ($)** | **Total capital loss carryforward ($)** |
| **Fidelity Short-Term Treasury Bond Index Fund**  | (36988824) | (138052405) | (175041229) |
| **Fidelity Intermediate Treasury Bond Index Fund**  | (68648929) | (444945334) | (513594263) |
| **Fidelity Long-Term Treasury Bond Index Fund**  | (49452399) | (499984876) | (549437275) |

---

**New Accounting Pronouncement.** In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures. Effective for annual periods beginning after December 15, 2024, the amendments require greater disaggregation of disclosures related to income taxes paid. The ASU allows for early adoption and amendments should be applied on a prospective basis. Management is currently evaluating the impact of the ASU but does not expect this guidance to materially impact the financial statements.

**4. Fees and Other Transactions with Affiliates.**

**Management Fee.** Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Funds with investment management related services for which the Funds pay a monthly management fee. The management fee is based on an annual rate of .03% of each Fund's average net assets. Under the management contract, the investment adviser pays all other operating expenses, except the compensation of the independent Trustees and certain other expenses such as interest expense.

**Interfund Trades.** Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board of Trustees. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. During the period, there were no interfund trades.

**Prior Fiscal Year Affiliated Redemptions In-Kind.** Shares that were redeemed in-kind for investments, including accrued interest and cash, if any, are shown in the table below; along with realized gain or loss on investments delivered through in-kind redemptions. The amount of the in-kind redemptions is included in share transactions in the accompanying Statement of Changes in Net Assets. There was no gain or loss for federal income tax purposes.

---

| | | | |
|:---|:---|:---|:---|
|  | **Shares** | **Total net realized gain or loss ($)** | **Total Proceeds ($)** |
| **Fidelity Short-Term Treasury Bond Index Fund** | 12488058 | 2010797 | 130000682 |
| **Fidelity Intermediate Treasury Bond Index Fund** | 252881098 | 98486612 | 2528810977 |

---

**5. Committed Line of Credit.**

Certain Funds participate with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes.

Commitment fees are charged based on the unused amount of the line of credit at an annual rate of .10%, and then allocated to each participating fund based on its pro-rata portion of the line of credit. The commitment fees are borne by the investment adviser.

Interest is charged to a participating fund based on its borrowings at an annual rate of .75% plus the highest of (i) daily SOFR plus a .10% spread adjustment, (ii) Federal Funds Effective Rate, or (iii) Overnight Bank Funding Rate. During the period, there were no borrowings on this line of credit.

The line of credit agreement will expire in March 2026 unless extended or renewed.

**6. Security Lending.** 

Funds lend portfolio securities from time to time in order to earn additional income. Lending agents are used, including National Financial Services (NFS), an affiliate of the investment adviser. Pursuant to a securities lending agreement, NFS will receive a fee, which is capped at 9.9% of a fund's daily lending revenue, for its services as lending agent. A fund may lend securities to certain qualified borrowers, including NFS. On the settlement date of the loan, the borrowers provide collateral (in the form of U.S. Treasury obligations, letters of credit and/or cash) against the loaned securities and maintains collateral in an amount not less than 100% of the fair value of the loaned securities during the period of the loan. The fair value of the loaned securities is determined at the close of business of a fund and any additional required collateral is delivered to a fund on the next business day. A fund or borrower may terminate the loan at any time, and if the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund may apply collateral received from the borrower against the obligation. A fund may experience delays and costs in recovering the securities loaned or gaining access to non-cash collateral. Any cash collateral received is invested in the Fidelity Securities Lending Cash Central Fund. Any loaned securities are identified as such in the Schedule of Investments, and the value of loaned securities and cash collateral at period end, as applicable, are presented in the Statement of Assets and Liabilities. Security lending income represents the income earned on investing cash collateral less rebates paid to borrowers, plus any premium income received, or for non-cash collateral, fees received from borrowers as compensation for the securities loaned. Securities lending income is reduced by any lending agent fees associated with the loan. Any security lending income earned on investing cash collateral is presented in the Statement of Operations as a component of income from Fidelity Central Funds. Any security lending income earned on non-cash collateral is presented in the Statement of Operations as a component of interest. Affiliated security lending activity, if any, was as follows:

---

| | | | |
|:---|:---|:---|:---|
|  | **Total Security Lending Fees Paid to NFS ($)** | **Security Lending Income From Securities Loaned to NFS ($)** | **Value of Securities Loaned to NFS at Period End ($)** |
| **Fidelity Short-Term Treasury Bond Index Fund** | 1318 | - | - |
| **Fidelity Intermediate Treasury Bond Index Fund** | 983 | - | - |
| **Fidelity Long-Term Treasury Bond Index Fund** | 819 | - | - |

---

**7. Expense Reductions.** 

Through arrangements with each applicable Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce each applicable Fund's expenses. All of the applicable expense reductions are noted in the table below.

---

| | |
|:---|:---|
|  | **Custodian credits ($)** |
| **Fidelity Short-Term Treasury Bond Index Fund**  | 4 |
| **Fidelity Intermediate Treasury Bond Index Fund**  | 6 |
| **Fidelity Long-Term Treasury Bond Index Fund**  | 211 |

---

**8. Other.**

A fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the fund. In the normal course of business, a fund may also enter into contracts that provide general indemnifications. A fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against a fund. The risk of material loss from such claims is considered remote.

**9. Risk and Uncertainties.**

Many factors affect a fund's performance. Developments that disrupt global economies and financial markets, such as public health emergencies, military conflicts, terrorism, government restrictions, political changes, and environmental disasters, may significantly affect a fund's investment performance. The effects of these developments to a fund will be impacted by the types of securities in which a fund invests, the financial condition, industry, economic sector, and geographic location of an issuer, and a fund's level of investment in the securities of that issuer. Significant concentrations in security types, issuers, industries, sectors, and geographic locations may magnify the factors that affect a fund's performance.

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

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 9: Proxy Disclosures for Open-End Management Investment Companies**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies**

**(Unaudited)**

Note: This information is disclosed as part of the financial statements for each Fund as part of Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies.

**Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

![](img114165_4.jpg)<br>

1.9885079.107 LBX-I-SANN-1025

**Fidelity® SAI Short-Term Treasury Bond Index Fund**

**Semi-Annual Report**

**August 31, 2025**

Offered exclusively to certain clients of the Adviser, or its affiliates, including Strategic Advisers LLC (Strategic Advisers) - not available for sale to the general public. Fidelity® SAI is a product name of Fidelity® funds dedicated to certain programs affiliated with Strategic Advisers.

![](img114174_1.jpg)

![](img114174_2.jpg)

**Contents**

---

| |
|:---|
| **[Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)](#Sec_Item7_STN-SANN_0)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® SAI Short-Term Treasury Bond Index Fund](#Sub_Sec_Fund_7700_STN-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Notes to Financial Statements](#Sub_Sec_NotestoFinancialStatements7700_STN-SANN)** |
| **[Item 8: Changes in and Disagreements with Accountants for Open-End Management Investment Companies](#Sec_Item8_STN-SANN)** |
| **[Item 9: Proxy Disclosures for Open-End Management Investment Companies](#Sec_Item9_STN-SANN)** |
| **[Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies](#Sec_Item10_STN-SANN)** |
| **[Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract](#Sec_Item11_STN-SANN)** |

---

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov.

You may also call 1-800-544-3455 to request a free copy of the proxy voting guidelines.

"BLOOMBERG®" and the Bloomberg indices listed herein (the "Indices") are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL"), the administrator of the Indices (collectively, "Bloomberg") and have been licensed for use for certain purposes by Fidelity. Bloomberg is not affiliated with Fidelity, and Bloomberg does not approve, endorse, review, or recommend the fund. Bloomberg does not guarantee the timeliness, accuracy, or completeness of any data or information relating to the fund.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.© 2025 FMR LLC. All rights reserved.

*This report and the financial statements contained herein are submitted for the general information of the shareholders of the Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.*

*A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. Forms N-PORT are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-PORT may be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.*

*For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.*

**NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE**

*Neither the Fund nor Fidelity Distributors Corporation is a bank.*

**Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)**

**Fidelity® SAI Short-Term Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 98.8%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 98.8%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 98.8%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 98.8%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 5.5% 8/15/2028  | 3.40 | 480400 | 506447 |
| US Treasury Bonds 6% 2/15/2026  | 3.52 | 239500 | 241549 |
| US Treasury Bonds 6.375% 8/15/2027  | 3.42 | 561900 | 591136 |
| US Treasury Bonds 6.5% 11/15/2026  | 3.23 | 179600 | 185885 |
| US Treasury Notes 0.375% 11/30/2025  | 3.84 | 152800 | 151386 |
| US Treasury Notes 0.375% 7/31/2027  | 3.49 | 2888600 | 2716412 |
| US Treasury Notes 0.5% 10/31/2027  | 3.50 | 1591700 | 1489483 |
| US Treasury Notes 0.5% 4/30/2027  | 3.51 | 693500 | 658337 |
| US Treasury Notes 0.5% 5/31/2027  | 3.51 | 1606300 | 1521279 |
| US Treasury Notes 0.5% 6/30/2027  | 4.22 | 1200000 | 1133813 |
| US Treasury Notes 0.5% 8/31/2027  | 3.49 | 193800 | 182248 |
| US Treasury Notes 0.625% 11/30/2027  | 3.50 to 4.01 | 3764400 | 3525449 |
| US Treasury Notes 0.625% 12/31/2027  | 3.50 | 532900 | 497720 |
| US Treasury Notes 0.625% 3/31/2027  | 3.52 | 242200 | 230913 |
| US Treasury Notes 0.625% 5/15/2030  | 3.98 | 700000 | 608316 |
| US Treasury Notes 0.75% 1/31/2028  | 3.50 | 2924300 | 2733307 |
| US Treasury Notes 0.875% 9/30/2026  | 3.56 | 1238700 | 1200233 |
| US Treasury Notes 1% 7/31/2028  | 3.51 | 2216200 | 2058902 |
| US Treasury Notes 1.125% 2/29/2028  | 3.50 to 3.70 | 2888300 | 2719853 |
| US Treasury Notes 1.125% 8/31/2028  | 3.62 | 600000 | 558281 |
| US Treasury Notes 1.25% 11/30/2026  | 3.55 | 1401600 | 1358676 |
| US Treasury Notes 1.25% 12/31/2026  | 3.52 | 3592700 | 3476358 |
| US Treasury Notes 1.25% 3/31/2028  | 3.50 to 3.88 | 602400 | 567950 |
| US Treasury Notes 1.25% 4/30/2028  | 3.51 to 3.87 | 1896000 | 1784536 |
| US Treasury Notes 1.25% 5/31/2028  | 3.70 | 2200000 | 2066367 |
| US Treasury Notes 1.25% 6/30/2028  | 3.50 to 3.60 | 602200 | 564680 |
| US Treasury Notes 1.25% 9/30/2028  | 3.51 | 2909700 | 2712386 |
| US Treasury Notes 1.5% 1/31/2027  | 3.53 | 474700 | 460107 |
| US Treasury Notes 1.5% 11/30/2028  | 3.87 | 550000 | 514959 |
| US Treasury Notes 1.5% 2/15/2030  | 3.71 | 550000 | 501789 |
| US Treasury Notes 1.5% 8/15/2026  | 3.60 | 292400 | 285960 |
| US Treasury Notes 1.875% 2/28/2027  | 3.52 | 27600 | 26864 |
| US Treasury Notes 1.875% 7/31/2026  | 3.61 | 371800 | 365125 |
| US Treasury Notes 2.25% 2/15/2027  | 3.53 | 338400 | 331381 |
| US Treasury Notes 2.25% 8/15/2027  | 3.50 | 622500 | 606305 |
| US Treasury Notes 2.375% 3/31/2029  | 3.52 | 1735800 | 1664266 |
| US Treasury Notes 2.375% 5/15/2027  | 3.52 | 737300 | 721632 |
| US Treasury Notes 2.375% 5/15/2029  | 3.52 | 415900 | 398127 |
| US Treasury Notes 2.5% 3/31/2027  | 3.50 | 37700 | 37011 |
| US Treasury Notes 2.625% 5/31/2027  | 3.51 | 523900 | 514650 |
| US Treasury Notes 2.75% 2/15/2028  | 3.50 | 488800 | 479196 |
| US Treasury Notes 2.75% 4/30/2027  | 3.51 | 43400 | 42752 |
| US Treasury Notes 2.75% 5/31/2029  | 3.52 | 1041800 | 1010220 |
| US Treasury Notes 2.75% 7/31/2027  | 3.51 | 584900 | 575235 |
| US Treasury Notes 2.875% 4/30/2029  | 3.52 | 2067900 | 2015556 |
| US Treasury Notes 2.875% 5/15/2028  | 4.00 | 2550000 | 2503084 |
| US Treasury Notes 3.125% 8/31/2027  | 3.50 | 269200 | 266624 |
| US Treasury Notes 3.375% 9/15/2027  | 3.99 | 2550000 | 2538047 |
| US Treasury Notes 3.5% 4/30/2028  | 3.49 to 3.87 | 2366800 | 2361192 |
| US Treasury Notes 3.5% 9/30/2029  | 4.00 to 4.09 | 13350000 | 13278557 |
| US Treasury Notes 3.625% 3/31/2030  | 3.97 | 500000 | 498906 |
| US Treasury Notes 3.625% 5/15/2026  | 3.66 | 85600 | 85415 |
| US Treasury Notes 3.625% 8/15/2028  | 3.58 | 7950000 | 7960559 |
| US Treasury Notes 3.625% 8/31/2029  | 4.04 | 29200000 | 29186313 |
| US Treasury Notes 3.625% 8/31/2030  | 3.69 | 10100000 | 10069227 |
| US Treasury Notes 3.75% 12/31/2028  | 3.51 | 311500 | 312899 |
| US Treasury Notes 3.75% 4/15/2026  | 3.68 | 480400 | 479702 |
| US Treasury Notes 3.75% 4/15/2028  | 3.96 to 3.97 | 36550000 | 36689919 |
| US Treasury Notes 3.75% 4/30/2027  | 4.01 | 21200000 | 21222359 |
| US Treasury Notes 3.75% 5/15/2028  | 3.84 | 4200000 | 4217438 |
| US Treasury Notes 3.75% 5/31/2030  | 3.98 | 1550000 | 1554117 |
| US Treasury Notes 3.75% 6/30/2030  | 3.81 | 2250000 | 2256064 |
| US Treasury Notes 3.75% 8/15/2027  | 3.49 to 4.01 | 2302500 | 2307087 |
| US Treasury Notes 3.875% 10/15/2027  | 4.00 | 2450000 | 2462346 |
| US Treasury Notes 3.875% 3/15/2028  | 3.84 to 3.88 | 4150000 | 4179504 |
| US Treasury Notes 3.875% 3/31/2027  | 3.91 | 4650000 | 4661988 |
| US Treasury Notes 3.875% 4/30/2030  | 3.72 to 4.07 | 3400000 | 3428820 |
| US Treasury Notes 3.875% 5/31/2027  | 3.96 | 6500000 | 6521836 |
| US Treasury Notes 3.875% 6/15/2028  | 3.69 | 3900000 | 3930164 |
| US Treasury Notes 3.875% 6/30/2030  | 3.79 | 5050000 | 5091426 |
| US Treasury Notes 3.875% 7/15/2028  | 3.89 | 9350000 | 9422316 |
| US Treasury Notes 3.875% 7/31/2027  | 3.94 | 1850000 | 1857660 |
| US Treasury Notes 3.875% 7/31/2030  | 3.95 | 7350000 | 7409145 |
| US Treasury Notes 4% 1/31/2029  | 3.51 | 148000 | 149856 |
| US Treasury Notes 4% 12/15/2027  | 3.84 | 3300000 | 3329337 |
| US Treasury Notes 4% 2/28/2030  | 4.00 to 4.09 | 4850000 | 4918014 |
| US Treasury Notes 4% 2/29/2028  | 3.49 | 148300 | 149725 |
| US Treasury Notes 4% 3/31/2030  | 3.93 to 4.06 | 4700000 | 4764441 |
| US Treasury Notes 4% 5/31/2030  | 3.95 to 4.03 | 5100000 | 5170723 |
| US Treasury Notes 4% 6/30/2028  | 4.32 | 500000 | 505586 |
| US Treasury Notes 4% 7/31/2029  | 3.50 | 292800 | 296685 |
| US Treasury Notes 4.125% 1/31/2027  | 4.03 | 22150000 | 22259885 |
| US Treasury Notes 4.125% 10/31/2026  | 4.01 to 4.16 | 2600000 | 2608328 |
| US Treasury Notes 4.125% 10/31/2027  | 3.49 | 302900 | 306059 |
| US Treasury Notes 4.125% 10/31/2029  | 3.91 | 2050000 | 2087076 |
| US Treasury Notes 4.125% 11/15/2027  | 3.86 | 2300000 | 2324438 |
| US Treasury Notes 4.125% 11/30/2029  | 4.08 | 1200000 | 1221984 |
| US Treasury Notes 4.125% 2/28/2027  | 3.92 | 3200000 | 3218250 |
| US Treasury Notes 4.125% 3/31/2029  | 3.51 to 4.05 | 1773100 | 1803229 |
| US Treasury Notes 4.125% 6/15/2026  | 3.64 | 169200 | 169440 |
| US Treasury Notes 4.125% 7/31/2028  | 4.02 | 5350000 | 5428578 |
| US Treasury Notes 4.125% 9/30/2027  | 3.47 | 71000 | 71716 |
| US Treasury Notes 4.25% 1/15/2028  | 3.86 | 4150000 | 4210143 |
| US Treasury Notes 4.25% 1/31/2030  | 4.33 | 850000 | 870021 |
| US Treasury Notes 4.25% 11/30/2026  | 4.10 | 20750000 | 20860234 |
| US Treasury Notes 4.25% 2/15/2028  | 3.94 | 19950000 | 20253523 |
| US Treasury Notes 4.25% 6/30/2029  | 3.51 | 1362000 | 1392040 |
| US Treasury Notes 4.375% 11/30/2028  | 3.51 | 39700 | 40634 |
| US Treasury Notes 4.375% 12/31/2029  | 3.92 to 4.39 | 4650000 | 4781689 |
| US Treasury Notes 4.375% 7/15/2027  | 3.49 | 342600 | 347026 |
| US Treasury Notes 4.375% 7/31/2026  | 4.04 | 130200 | 130734 |
| US Treasury Notes 4.375% 8/31/2028  | 3.50 | 83800 | 85653 |
| US Treasury Notes 4.5% 3/31/2026  | 3.70 | 94000 | 94257 |
| US Treasury Notes 4.5% 5/31/2029  | 3.89 | 4650000 | 4790590 |
| US Treasury Notes 4.625% 11/15/2026  | 3.56 | 81500 | 82267 |
| US Treasury Notes 4.625% 4/30/2029  | 3.89 | 1450000 | 1499504 |
| US Treasury Notes 4.625% 6/15/2027  | 3.49 | 100300 | 101942 |
| US Treasury Notes 4.625% 9/15/2026  | 3.59 | 264600 | 266683 |
| US Treasury Notes 4.625% 9/30/2028  | 4.01 | 1900000 | 1956777 |
| US Treasury Notes 4.875% 10/31/2028  | 4.02 | 2100000 | 2179324 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $355,637,028) |  |  | **358072142** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $1,745,614)<br>| 4.36 | 1745265 | **1745614** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 99.3%**<br> (Cost $357,382,642)<br>| <br>**359817756** |
| **NET OTHER ASSETS (LIABILITIES) - 0.7%**  | **2458847** |
| **NET ASSETS - 100.0%** | **362276603** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 528404 | 5205506 | 3988296 | 13937 | - | - | 1745614 | 1745265 | 0.0% |
| Total | 528404 | 5205506 | 3988296 | 13937 | - | - | 1745614 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 358072142 | - | 358072142 | - |
|  **Money Market Funds** | 1745614 | 1745614 | - | - |
| **Total Investments in Securities:** | 359817756 | 1745614 | 358072142 | - |

---

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $355,637,028) | $358072142 |  |
| Fidelity Central Funds (cost $1,745,614) | 1745614 |  |
| Total Investment in Securities (cost $357,382,642) |  | $359817756 |
| Receivable for investments sold |  | 16896372 |
| Interest receivable |  | 3617200 |
| Distributions receivable from Fidelity Central Funds |  | 5290 |
| Prepaid expenses |  | 428 |
| Receivable from investment adviser for expense reductions |  | 8884 |
| **Total assets** |  | 380345930 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $18030574 |  |
| Accrued management fee | 9008 |  |
| Other payables and accrued expenses | 29745 |  |
| **Total liabilities** |  | 18069327 |
| **Net Assets**  |  | $362276603 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $359301734 |
| Total accumulated earnings (loss) |  | 2974869 |
| **Net Assets** |  | $362276603 |
| **Net Asset Value**, offering price and redemption price per share ($362,276,603 ÷ 35,863,093 shares) |  | $10.10 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $4110374 |
| Income from Fidelity Central Funds  |  | 13937 |
| **Total income** |  | 4124311 |
| **Expenses** |  |  |
| Management fee | $31678 |  |
| Custodian fees and expenses | 213 |  |
| Independent trustees' fees and expenses | 191 |  |
| Registration fees | 25255 |  |
| Audit fees | 22793 |  |
| Legal | 18 |  |
| Miscellaneous | 182 |  |
| Total expenses before reductions | 80330 |  |
| Expense reductions | (48243) |  |
| Total expenses after reductions |  | 32087 |
| **Net Investment income (loss)** |  | 4092224 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (72452) |  |
| Total net realized gain (loss) |  | (72452) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | 3152790 |
| **Net gain (loss)** |  | 3080338 |
| **Net increase (decrease) in net assets resulting from operations** |  | $7172562 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **For the period September 20, 2024 (commencement of operations) through February 28, 2025**  |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $4092224 | $1357116 |
| &nbsp;&nbsp;Net realized gain (loss) | (72452)<br>| (554082)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | 3152790 | (717676)<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | 7172562<br>| 85358<br>|
| Distributions to shareholders | (3485894)<br>| (797917)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 300000050 | 130500983 |
| Reinvestment of distributions | 3485894<br>| 797917<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (25000050) | (50482300) |
| **Net increase (decrease) in net assets resulting from share transactions** | 278485894<br>| 80816600<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 282172562<br>| 80104041<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 80104041 | -<br>|
| &nbsp;&nbsp;End of period | $362276603 | $80104041 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 29987567 | 13050098 |
| Issued in reinvestment of distributions | 346552<br>| 80681<br>|
| &nbsp;&nbsp;Redeemed | (2512568) | (5089237) |
| &nbsp;&nbsp;Net increase (decrease) | 27821551 | 8041542 |

---

**Financial Highlights** 

**Fidelity® SAI Short-Term Treasury Bond Index Fund** <br>

---

| | | |
|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025** A |
| **Selected Per-Share Data**  |  |  |
| Net asset value, beginning of period  | $19.96 | $10.00 |
| Income from Investment Operations  |  |  |
| Net investment income (loss) B,C | .192  | .153  |
| Net realized and unrealized gain (loss)  | (9.910) D | (.099)  |
| Total from investment operations  | (9.718)  | .054  |
| Distributions from net investment income  | (.142)  | (.094)  |
| Total distributions  | (.142)  | (.094)  |
| Net asset value, end of period  | $10.10 | $9.96 |
| **Total Return** E,F | 2.85% <br>| .55%  |
| **Ratios to Average Net Assets** C,G,H |  |  |
| Expenses before reductions  | .08% I | .11% I,J |
| Expenses net of fee waivers, if any  | .03% I<br>| .03% I |
| Expenses net of all reductions, if any  | .03% I | .03% I |
| Net investment income (loss)  | 3.84% I | 3.59% I |
| **Supplemental Data** |  |  |
| Net assets, end of period (000 omitted) | $362277 | $80104 |
| Portfolio turnover rate K | 82% I<br>| 32% L,M |

---

A*For the period September 20, 2024 (commencement of operations) through February 28, 2025.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*The amount shown for a share outstanding does not correspond with the aggregate net gain (loss) on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating market values of the investments of the Fund.*

E*Total returns for periods of less than one year are not annualized.*

F*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

G*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

H*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

I*Annualized.*

J*Audit fees are not annualized.*

K*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

L*Portfolio turnover rate excludes securities received or delivered in-kind.*

M*Amount not annualized.*

**Notes to Financial Statements** **(Unaudited)**

For the period ended August 31, 2025

**1. Organization.**

Fidelity SAI Short-Term Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered exclusively to certain clients of Fidelity Management & Research Company LLC (FMR) or its affiliates. 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.

**2. Investments in Fidelity Central Funds.**

Funds may invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Schedule of Investments lists any Fidelity Central Funds held as an investment as of period end, but does not include the underlying holdings of each Fidelity Central Fund. An investing fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

Based on its investment objective, each Fidelity Central Fund may invest or participate in various investment vehicles or strategies that are similar to those of the investing fund. These strategies are consistent with the investment objectives of the investing fund and may involve certain economic risks which may cause a decline in value of each of the Fidelity Central Funds and thus a decline in the value of the investing fund.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fidelity Central Fund** | **Investment Manager** | **Investment Objective** | **Investment Practices** | **Expense RatioA** |
| Fidelity Money Market Central Funds | Fidelity Management & Research Company LLC (FMR) | Each fund seeks to obtain a high level of current income consistent with the preservation of capital and liquidity. | Short-term Investments | Less than .005% |

---

*A Expenses expressed as a percentage of average net assets and are as of each underlying Central Fund's most recent annual or semi-annual shareholder report.* 

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds which contain the significant accounting policies (including investment valuation policies) of those funds, and are not covered by the Report of Independent Registered Public Accounting Firm, are available on the Securities and Exchange Commission website or upon request.

**3. Significant Accounting Policies.**

The Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 *Financial Services - Investment Companies*. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. The Fund operates as a single operating segment. The Fund's income, expenses, assets, and performance are regularly monitored and assessed as a whole by the investment adviser and other individuals responsible for oversight functions of the Trust, using the information presented in the financial statements and financial highlights. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The Fund's Schedule of Investments lists any underlying mutual funds or exchange-traded funds but does not include the underlying holdings of these funds. The following summarizes the significant accounting policies of the Fund:

**Investment Valuation.** Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has designated the Fund's investment adviser as the valuation designee responsible for the fair valuation function and performing fair value determinations as needed. The investment adviser has established a Fair Value Committee (the Committee) to carry out the day-to-day fair valuation responsibilities and has adopted policies and procedures to govern the fair valuation process and the activities of the Committee. In accordance with these fair valuation policies and procedures, which have been approved by the Board, the Fund attempts to obtain prices from one or more third party pricing services or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with the policies and procedures. Factors used in determining fair value vary by investment type and may include market or investment specific events, transaction data, estimated cash flows, and market observations of comparable investments. The frequency that the fair valuation procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee manages the Fund's fair valuation practices and maintains the fair valuation policies and procedures. The Fund's investment adviser reports to the Board information regarding the fair valuation process and related material matters.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing services or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing services who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing services. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of August 31, 2025 is included at the end of the Fund's Schedule of Investments.

**Investment Transactions and Income.** For financial reporting purposes, the Fund's investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

**Expenses.** Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

**Income Tax Information and Distributions to Shareholders.** Each year, the Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. The Fund files a U.S. federal tax return, in addition to state and local tax returns as required. The Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

---

| | |
|:---|:---|
| **Gross unrealized appreciation** | $3296566 |
| **Gross unrealized depreciation** | <u>(21137)</u> |
| **Net unrealized appreciation (depreciation)** | <u>$3275429</u> |
| **Tax cost** | <u>$356542327</u> |

---

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of prior fiscal period end and is subject to adjustment.

---

| | |
|:---|:---|
| Short-term | $(445417) |
| Long-term | <u>-</u> |
| **Total capital loss carryforward** | <u>$(445417)</u> |

---

**New Accounting Pronouncement.** 

In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures. Effective for annual periods beginning after December 15, 2024, the amendments require greater disaggregation of disclosures related to income taxes paid. The ASU allows for early adoption and amendments should be applied on a prospective basis. Management is currently evaluating the impact of the ASU but does not expect this guidance to materially impact the financial statements.

**4. Fees and Other Transactions with Affiliates.**

**Management Fee.** Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund pays a monthly management fee that is based on an annual rate of .03% of the Fund's average net assets.

**Interfund Trades.** Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board of Trustees. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Any interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note. During the period, there were no interfund trades.

**Prior Fiscal Year Affiliated Exchanges In-Kind.** Shares that were exchanged for investments, including accrued interest and cash, if any, are shown in the table below. The amount of in-kind exchanges is included in share transactions in the accompanying Statement of Changes in Net Assets.

---

| | | |
|:---|:---|:---|
|  | **Shares** | **Total Proceeds ($)** |
| **Fidelity SAI Short-Term Treasury Bond Index Fund** | 13000068 | 130000682 |

---

**5. Expense Reductions.**

The investment adviser contractually agreed to reimburse the Fund to the extent annual operating expenses exceeded .03% of average net assets. This reimbursement will remain in place through June 30, 2026. Some expenses, for example the compensation of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses, are excluded from this reimbursement. During the period this reimbursement reduced the Fund's expenses by $48,127.

Through arrangements with the Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses by $116.

**6. Other.**

A fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the fund. In the normal course of business, a fund may also enter into contracts that provide general indemnifications. A fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against a fund. The risk of material loss from such claims is considered remote.

At the end of the period, the following mutual funds managed by the investment adviser or its affiliates were the owners of record of 10% or more of the total outstanding shares.

---

| | |
|:---|:---|
|  | **Strategic Advisers Fidelity Core Income Fund** |
| Fidelity SAI Short-Term Treasury Bond Index Fund | 100% |

---

**7. Risk and Uncertainties.**

Many factors affect a fund's performance. Developments that disrupt global economies and financial markets, such as public health emergencies, military conflicts, terrorism, government restrictions, political changes, and environmental disasters, may significantly affect a fund's investment performance. The effects of these developments to a fund will be impacted by the types of securities in which a fund invests, the financial condition, industry, economic sector, and geographic location of an issuer, and a fund's level of investment in the securities of that issuer. Significant concentrations in security types, issuers, industries, sectors, and geographic locations may magnify the factors that affect a fund's performance.

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

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 9: Proxy Disclosures for Open-End Management Investment Companies**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies**

**(Unaudited)**

Note: This information is disclosed as part of the financial statements for each Fund as part of Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies.

**Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

![](img114174_4.jpg)<br>

1.9918129.100 STN-SANN-1025

**Fidelity® SAI Intermediate Treasury Bond Index Fund**

**Semi-Annual Report**

**August 31, 2025**

Offered exclusively to certain clients of the Adviser, or its affiliates, including Strategic Advisers LLC (Strategic Advisers) - not available for sale to the general public. Fidelity® SAI is a product name of Fidelity® funds dedicated to certain programs affiliated with Strategic Advisers.

![](img114175_1.jpg)

![](img114175_2.jpg)

**Contents**

---

| |
|:---|
| **[Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)](#Sec_Item7_TBN-SANN_0)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® SAI Intermediate Treasury Bond Index Fund](#Sub_Sec_Fund_7703_TBN-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Notes to Financial Statements](#Sub_Sec_NotestoFinancialStatements7703_TBN-SANN)** |
| **[Item 8: Changes in and Disagreements with Accountants for Open-End Management Investment Companies](#Sec_Item8_TBN-SANN)** |
| **[Item 9: Proxy Disclosures for Open-End Management Investment Companies](#Sec_Item9_TBN-SANN)** |
| **[Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies](#Sec_Item10_TBN-SANN)** |
| **[Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract](#Sec_Item11_TBN-SANN)** |

---

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov.

You may also call 1-800-544-3455 to request a free copy of the proxy voting guidelines.

"BLOOMBERG®" and the Bloomberg indices listed herein (the "Indices") are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL"), the administrator of the Indices (collectively, "Bloomberg") and have been licensed for use for certain purposes by Fidelity. Bloomberg is not affiliated with Fidelity, and Bloomberg does not approve, endorse, review, or recommend the fund. Bloomberg does not guarantee the timeliness, accuracy, or completeness of any data or information relating to the fund.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.© 2025 FMR LLC. All rights reserved.

*This report and the financial statements contained herein are submitted for the general information of the shareholders of the Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.*

*A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. Forms N-PORT are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-PORT may be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.*

*For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.*

**NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE**

*Neither the Fund nor Fidelity Distributors Corporation is a bank.*

**Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)**

**Fidelity® SAI Intermediate Treasury Bond Index Fund**

**Schedule of Investments August 31, 2025 (Unaudited)**

Showing Percentage of Net Assets

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** | &nbsp;&nbsp;**U.S. Treasury Obligations - 99.2%** |
|  | Yield (%) (a) | Principal<br> Amount (b)<br>| Value ($)<br>|
| US Treasury Bonds 5.25% 2/15/2029  | 3.41 | 1383100 | 1460142 |
| US Treasury Bonds 6.25% 5/15/2030  | 3.55 | 3229400 | 3583373 |
| US Treasury Notes 0.625% 5/15/2030  | 4.12 | 2578200 | 2240515 |
| US Treasury Notes 0.625% 8/15/2030  | 3.56 to 4.06 | 12684700 | 10931139 |
| US Treasury Notes 0.875% 11/15/2030  | 3.56 to 4.05 | 124034100 | 107512371 |
| US Treasury Notes 1.125% 2/15/2031  | 3.81 to 4.31 | 97700000 | 85327211 |
| US Treasury Notes 1.25% 8/15/2031  | 3.61 to 4.25 | 183926400 | 158931089 |
| US Treasury Notes 1.375% 11/15/2031  | 3.63 to 4.15 | 134454600 | 116182430 |
| US Treasury Notes 1.625% 5/15/2031  | 3.60 to 4.02 | 102457900 | 91199538 |
| US Treasury Notes 1.875% 2/15/2032  | 3.65 to 4.11 | 111748000 | 99000000 |
| US Treasury Notes 2.75% 8/15/2032  | 3.66 to 4.58 | 121463800 | 112776291 |
| US Treasury Notes 2.875% 5/15/2032  | 3.65 | 114149900 | 107220645 |
| US Treasury Notes 3.375% 5/15/2033  | 3.69 to 4.27 | 125561700 | 120347946 |
| US Treasury Notes 3.5% 2/15/2033  | 3.68 to 4.35 | 131554700 | 127515560 |
| US Treasury Notes 3.625% 9/30/2031  | 3.66 to 4.13 | 37200000 | 36781500 |
| US Treasury Notes 3.75% 12/31/2030  | 4.13 to 4.14 | 47450000 | 47466682 |
| US Treasury Notes 3.75% 8/31/2031  | 3.61 to 4.38 | 10050000 | 10010349 |
| US Treasury Notes 3.875% 8/15/2033  | 3.70 to 4.61 | 118605400 | 117363750 |
| US Treasury Notes 3.875% 8/15/2034  | 3.73 to 4.63 | 138399400 | 135696294 |
| US Treasury Notes 4% 1/31/2031  | 3.59 | 24561300 | 24852965 |
| US Treasury Notes 4% 2/15/2034  | 3.72 to 4.42 | 163007200 | 162052079 |
| US Treasury Notes 4% 4/30/2032  | 3.93 to 4.26 | 65600000 | 65979250 |
| US Treasury Notes 4% 6/30/2032  | 3.99 to 4.12 | 48050000 | 48297758 |
| US Treasury Notes 4% 7/31/2032  | 4.01 to 4.14 | 70000000 | 70317188 |
| US Treasury Notes 4.125% 10/31/2031  | 4.15 to 4.22 | 79300000 | 80511184 |
| US Treasury Notes 4.125% 11/15/2032  | 3.66 to 4.01 | 107778900 | 108982993 |
| US Treasury Notes 4.125% 11/30/2031  | 4.16 to 4.56 | 58100000 | 58962422 |
| US Treasury Notes 4.125% 2/29/2032  | 4.03 to 4.10 | 49950000 | 50642666 |
| US Treasury Notes 4.125% 3/31/2031  | 3.59 to 3.96 | 115017600 | 117048380 |
| US Treasury Notes 4.125% 3/31/2032  | 4.08 to 4.15 | 63350000 | 64203740 |
| US Treasury Notes 4.125% 5/31/2032  | 3.91 to 4.29 | 124250000 | 125816308 |
| US Treasury Notes 4.125% 7/31/2031  | 3.98 | 28866200 | 29339346 |
| US Treasury Notes 4.25% 11/15/2034  | 4.16 to 4.58 | 165850000 | 166938391 |
| US Treasury Notes 4.25% 2/28/2031  | 3.59 to 3.97 | 159628300 | 163475591 |
| US Treasury Notes 4.25% 5/15/2035  | 4.23 to 4.39 | 138100000 | 138531563 |
| US Treasury Notes 4.25% 6/30/2031  | 3.92 to 4.03 | 49200000 | 50335828 |
| US Treasury Notes 4.25% 8/15/2035  | 4.22 | 55150000 | 55262023 |
| US Treasury Notes 4.375% 1/31/2032  | 4.18 to 4.44 | 45600000 | 46875375 |
| US Treasury Notes 4.375% 11/30/2030  | 3.59 to 3.97 | 13535300 | 13944003 |
| US Treasury Notes 4.375% 5/15/2034  | 3.73 to 4.45 | 126737700 | 129213046 |
| US Treasury Notes 4.5% 11/15/2033  | 3.71 to 4.37 | 144727400 | 149238825 |
| US Treasury Notes 4.5% 12/31/2031  | 4.49 | 39750000 | 41156777 |
| US Treasury Notes 4.625% 2/15/2035  | 4.16 to 4.48 | 143850000 | 148772374 |
| US Treasury Notes 4.625% 4/30/2031  | 3.59 to 4.04 | 54707800 | 57035018 |
| US Treasury Notes 4.625% 5/31/2031  | 3.60 to 4.13 | 35941900 | 37465219 |
| US Treasury Notes 4.625% 9/30/2030  | 3.58 to 4.52 | 16730000 | 17426648 |
| US Treasury Notes 4.875% 10/31/2030  | 3.57 | 47822400 | 50377910 |
| <br> **TOTAL U.S. TREASURY OBLIGATIONS**<br> (Cost $3,761,581,883) |  |  | **3764601695** |

---

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** | &nbsp;&nbsp;**Money Market Funds - 0.5%** |
|  | Yield (%) | Shares | Value ($)<br>|
| Fidelity Cash Central Fund (c)<br>(Cost $17,279,012)<br>| 4.36 | 17275556 | **17279012** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 99.7%**<br> (Cost $3,778,860,895)<br>| <br>**3781880707** |
| **NET OTHER ASSETS (LIABILITIES) - 0.3%**  | **12061900** |
| **NET ASSETS - 100.0%** | **3793942607** |

---

**Legend**

(a) Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b) Amount is stated in United States dollars unless otherwise noted.

(c) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements are available on the SEC's website or upon request.

**Affiliated Central Funds**

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Affiliate  | Value,<br> beginning<br> of period ($) | Purchases ($) | Sales<br> Proceeds ($) | Dividend<br> Income ($) | Realized<br> Gain (loss) ($) | Change in<br> Unrealized<br> appreciation<br> (depreciation) ($) | Value,<br> end<br> of period ($) | <br>Shares,<br> end<br> of period  | % ownership,<br> end<br> of period |
| Fidelity Cash Central Fund | 18742564 | 57415621 | 58879173 | 130581 | - | - | 17279012 | 17275556 | 0.0% |
| Total | 18742564 | 57415621 | 58879173 | 130581 | - | - | 17279012 |  |  |

---

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

**Investment Valuation**

The following is a summary of the inputs used, as of August 31, 2025, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** | **Valuation Inputs at Reporting Date:** |
| **Description** | **Total ($)** | **Level 1 ($)** | **Level 2 ($)** | **Level 3 ($)** |
|  **<u>Investments in Securities:</u>** |  |  |  |  |
|  **U.S. Treasury Obligations** | 3764601695 | - | 3764601695 | - |
|  **Money Market Funds** | 17279012 | 17279012 | - | - |
| **Total Investments in Securities:** | 3781880707 | 17279012 | 3764601695 | - |

---

**Financial Statements (Unaudited)**

---

| | | |
|:---|:---|:---|
| **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** | **Statement of Assets and Liabilities** |
| <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** | <br> **As of August 31, 2025 (Unaudited)** |
| **Assets**  |  |  |
| Investment in securities, at value - See accompanying schedule: |  |  |
| Unaffiliated issuers (cost $3,761,581,883) | $3764601695 |  |
| Fidelity Central Funds (cost $17,279,012) | 17279012 |  |
| Total Investment in Securities (cost $3,778,860,895) |  | $3781880707 |
| Cash |  | 1 |
| Receivable for investments sold |  | 152305628 |
| Interest receivable |  | 30101252 |
| Distributions receivable from Fidelity Central Funds |  | 41968 |
| Prepaid expenses |  | 4240 |
| Receivable from investment adviser for expense reductions |  | 36157 |
| **Total assets** |  | 3964369953 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $170278195 |  |
| Accrued management fee | 92080 |  |
| Other payables and accrued expenses | 57071 |  |
| **Total liabilities** |  | 170427346 |
| **Net Assets**  |  | $3793942607 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $3792360993 |
| Total accumulated earnings (loss) |  | 1581614 |
| **Net Assets** |  | $3793942607 |
| **Net Asset Value**, offering price and redemption price per share ($3,793,942,607 ÷ 382,863,001 shares) |  | $9.91 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Operations** | **Statement of Operations** | **Statement of Operations** |
| **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** | **Six months ended August 31, 2025 (Unaudited)** |
| **Investment Income** |  |  |
| Interest  |  | $62994836 |
| Income from Fidelity Central Funds  |  | 130581 |
| **Total income** |  | 63125417 |
| **Expenses** |  |  |
| Management fee | $480345 |  |
| Custodian fees and expenses | 237 |  |
| Independent trustees' fees and expenses | 3528 |  |
| Registration fees | 49071 |  |
| Audit fees | 22891 |  |
| Legal | 743 |  |
| Miscellaneous | 3872 |  |
| Total expenses before reductions | 560687 |  |
| Expense reductions | (72806) |  |
| Total expenses after reductions |  | 487881 |
| **Net Investment income (loss)** |  | 62637536 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Unaffiliated issuers  | (7504344) |  |
| Total net realized gain (loss) |  | (7504344) |
| Change in net unrealized appreciation (depreciation) on investment securities  |  | 60272679 |
| **Net gain (loss)** |  | 52768335 |
| **Net increase (decrease) in net assets resulting from operations** |  | $115405871 |

---

---

| | | |
|:---|:---|:---|
| **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** | **Statement of Changes in Net Assets** |
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)** | **For the period September 20, 2024 (commencement of operations) through February 28, 2025**  |
| **Increase (Decrease) in Net Assets** |  |  |
| Operations |  |  |
| &nbsp;&nbsp;Net investment income (loss) | $62637536 | $44899983 |
| &nbsp;&nbsp;Net realized gain (loss) | (7504344)<br>| (12950357)<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | 60272679 | (57252867)<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | 115405871<br>| (25303241)<br>|
| Distributions to shareholders | (52375307)<br>| (36188747)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 1100000000 | 2904311277 |
| Reinvestment of distributions | 52375307<br>| 36188747<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (300000000) | (471300) |
| **Net increase (decrease) in net assets resulting from share transactions** | 852375307<br>| 2940028724<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 915405871<br>| 2878536736<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 2878536736 | -<br>|
| &nbsp;&nbsp;End of period | $3793942607 | $2878536736 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 112712358 | 291445943 |
| Issued in reinvestment of distributions | 5332772<br>| 3754691<br>|
| &nbsp;&nbsp;Redeemed | (30333670) | (49093) |
| &nbsp;&nbsp;Net increase (decrease) | 87711460 | 295151541 |

---

**Financial Highlights** 

**Fidelity® SAI Intermediate Treasury Bond Index Fund** <br>

---

| | | |
|:---|:---|:---|
|  | **Six months ended**<br> **August 31, 2025**<br> **(Unaudited)**  | **Years ended February 28, 2025** A |
| **Selected Per-Share Data**  |  |  |
| Net asset value, beginning of period  | $19.75 | $10.00 |
| Income from Investment Operations  |  |  |
| Net investment income (loss) B,C | .190  | .158  |
| Net realized and unrealized gain (loss)  | (9.871) D | (.278)  |
| Total from investment operations  | (9.681)  | (.120)  |
| Distributions from net investment income  | (.159)  | (.130)  |
| Total distributions  | (.159)  | (.130)  |
| Net asset value, end of period  | $9.91 | $9.75 |
| **Total Return** E,F | 3.30% <br>| (1.18)%  |
| **Ratios to Average Net Assets** C,G,H |  |  |
| Expenses before reductions  | .03% I | .03% I,J |
| Expenses net of fee waivers, if any  | .03% I<br>| .03% I |
| Expenses net of all reductions, if any  | .03% I | .03% I |
| Net investment income (loss)  | 3.88% I | 3.77% I |
| **Supplemental Data** |  |  |
| Net assets, end of period (000 omitted) | $3793943 | $2878537 |
| Portfolio turnover rate K | 53% I<br>| 20% L,M |

---

A*For the period September 20, 2024 (commencement of operations) through February 28, 2025.*

B*Calculated based on average shares outstanding during the period.*

C*Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.*

D*The amount shown for a share outstanding does not correspond with the aggregate net gain (loss) on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating market values of the investments of the Fund.*

E*Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.*

F*Total returns for periods of less than one year are not annualized.*

G*Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.*

H*Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.*

I*Annualized.*

J*Audit fees are not annualized.*

K*Amount does not include the portfolio activity of any underlying mutual funds or exchange-traded funds (ETFs), derivatives or securities that mature within one year from acquisition.* 

L*Amount not annualized.*

M*Portfolio turnover rate excludes securities received or delivered in-kind.*

**Notes to Financial Statements** **(Unaudited)**

For the period ended August 31, 2025

**1. Organization.**

Fidelity SAI Intermediate Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered exclusively to certain clients of Fidelity Management & Research Company LLC (FMR) or its affiliates. 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.

**2. Investments in Fidelity Central Funds.**

Funds may invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Schedule of Investments lists any Fidelity Central Funds held as an investment as of period end, but does not include the underlying holdings of each Fidelity Central Fund. An investing fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

Based on its investment objective, each Fidelity Central Fund may invest or participate in various investment vehicles or strategies that are similar to those of the investing fund. These strategies are consistent with the investment objectives of the investing fund and may involve certain economic risks which may cause a decline in value of each of the Fidelity Central Funds and thus a decline in the value of the investing fund.

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Fidelity Central Fund** | **Investment Manager** | **Investment Objective** | **Investment Practices** | **Expense RatioA** |
| Fidelity Money Market Central Funds | Fidelity Management & Research Company LLC (FMR) | Each fund seeks to obtain a high level of current income consistent with the preservation of capital and liquidity. | Short-term Investments | Less than .005% |

---

*A Expenses expressed as a percentage of average net assets and are as of each underlying Central Fund's most recent annual or semi-annual shareholder report.* 

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds which contain the significant accounting policies (including investment valuation policies) of those funds, and are not covered by the Report of Independent Registered Public Accounting Firm, are available on the Securities and Exchange Commission website or upon request.

**3. Significant Accounting Policies.**

The Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 *Financial Services - Investment Companies*. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. The Fund operates as a single operating segment. The Fund's income, expenses, assets, and performance are regularly monitored and assessed as a whole by the investment adviser and other individuals responsible for oversight functions of the Trust, using the information presented in the financial statements and financial highlights. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The Fund's Schedule of Investments lists any underlying mutual funds or exchange-traded funds but does not include the underlying holdings of these funds. The following summarizes the significant accounting policies of the Fund:

**Investment Valuation.** Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has designated the Fund's investment adviser as the valuation designee responsible for the fair valuation function and performing fair value determinations as needed. The investment adviser has established a Fair Value Committee (the Committee) to carry out the day-to-day fair valuation responsibilities and has adopted policies and procedures to govern the fair valuation process and the activities of the Committee. In accordance with these fair valuation policies and procedures, which have been approved by the Board, the Fund attempts to obtain prices from one or more third party pricing services or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with the policies and procedures. Factors used in determining fair value vary by investment type and may include market or investment specific events, transaction data, estimated cash flows, and market observations of comparable investments. The frequency that the fair valuation procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee manages the Fund's fair valuation practices and maintains the fair valuation policies and procedures. The Fund's investment adviser reports to the Board information regarding the fair valuation process and related material matters.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing services or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing services who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing services. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of August 31, 2025 is included at the end of the Fund's Schedule of Investments.

**Investment Transactions and Income.** For financial reporting purposes, the Fund's investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

**Expenses.** Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

**Income Tax Information and Distributions to Shareholders.** Each year, the Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. The Fund files a U.S. federal tax return, in addition to state and local tax returns as required. The Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

---

| | |
|:---|:---|
| **Gross unrealized appreciation** | $34672299 |
| **Gross unrealized depreciation** | <u>(17965517)</u> |
| **Net unrealized appreciation (depreciation)** | <u>$16706782</u> |
| **Tax cost** | <u>$3765173925</u> |

---

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of prior fiscal period end and is subject to adjustment.

---

| | |
|:---|:---|
| Short-term | $(11548951) |
| Long-term | <u>-</u> |
| **Total capital loss carryforward** | <u>$(11548951)</u> |

---

**New Accounting Pronouncement.** 

In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures. Effective for annual periods beginning after December 15, 2024, the amendments require greater disaggregation of disclosures related to income taxes paid. The ASU allows for early adoption and amendments should be applied on a prospective basis. Management is currently evaluating the impact of the ASU but does not expect this guidance to materially impact the financial statements.

**4. Fees and Other Transactions with Affiliates.**

**Management Fee.** Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund pays a monthly management fee that is based on an annual rate of .03% of the Fund's average net assets.

**Interfund Trades.** Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board of Trustees. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Any interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note. During the period, there were no interfund trades.

**Prior Fiscal Year Affiliated Exchanges In-Kind.** Shares that were exchanged for investments, including accrued interest and cash, if any, are shown in the table below. The amount of in-kind exchanges is included in share transactions in the accompanying Statement of Changes in Net Assets.

---

| | | |
|:---|:---|:---|
|  | **Shares** | **Total Proceeds ($)** |
| **Fidelity SAI Intermediate Treasury Bond Index Fund** | 252881098 | 2528810977 |

---

**5. Expense Reductions.**

The investment adviser contractually agreed to reimburse the Fund to the extent annual operating expenses exceeded .03% of average net assets. This reimbursement will remain in place through June 30, 2026. Some expenses, for example the compensation of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses, are excluded from this reimbursement. During the period this reimbursement reduced the Fund's expenses by $72,716.

Through arrangements with the Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses by $90.

**6. Other.**

A fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the fund. In the normal course of business, a fund may also enter into contracts that provide general indemnifications. A fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against a fund. The risk of material loss from such claims is considered remote.

At the end of the period, the following mutual funds managed by the investment adviser or its affiliates were the owners of record of 10% or more of the total outstanding shares.

---

| | |
|:---|:---|
|  | **Strategic Advisers Fidelity Core Income Fund** |
| Fidelity SAI Intermediate Treasury Bond Index Fund | 100%<br>|

---

**7. Risk and Uncertainties.**

Many factors affect a fund's performance. Developments that disrupt global economies and financial markets, such as public health emergencies, military conflicts, terrorism, government restrictions, political changes, and environmental disasters, may significantly affect a fund's investment performance. The effects of these developments to a fund will be impacted by the types of securities in which a fund invests, the financial condition, industry, economic sector, and geographic location of an issuer, and a fund's level of investment in the securities of that issuer. Significant concentrations in security types, issuers, industries, sectors, and geographic locations may magnify the factors that affect a fund's performance.

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

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 9: Proxy Disclosures for Open-End Management Investment Companies**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

**Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies**

**(Unaudited)**

Note: This information is disclosed as part of the financial statements for each Fund as part of Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies.

**Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract**

**(Unaudited)**

Note: This is not applicable for any fund included in this document.

![](img114175_4.jpg)<br>

1.9918127.100 TBN-SANN-1025

Item 8.

<u>Changes in and Disagreements with Accountants for Open-End Management Investment Companies</u>

See Item 7.

Item 9.

<u>Proxy Disclosures for Open-End Management Investment Companies</u>

See Item 7.

Item 10.

<u>Remuneration Paid to Directors, Officers, and Others of Open-End Management Investment Companies</u>

See Item 7.

Item 11.

<u>Statement Regarding Basis for Approval of Investment Advisory Contract</u>

See Item 7.

Item 12.

<u>Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies</u>

Not applicable.

Item 13.

<u>Portfolio Managers of Closed-End Management Investment Companies</u>

Not applicable.

Item 14.

<u>Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers</u>

Not applicable.

Item 15.

<u>Submission of Matters to a Vote of Security Holders</u>

There were no material changes to the procedures by which shareholders may recommend nominees to the Fidelity Salem Street Trust's Board of Trustees.

Item 16.

<u>Controls and Procedures</u>

(a)(i) The President and Treasurer and the Chief Financial Officer have concluded that the Fidelity Salem Street Trust's (the "Trust") disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act) provide reasonable assurances that material information relating to the Trust is made known to them by the appropriate persons, based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of this report.

(a)(ii) There was no change in the Trust's internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act) that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the Trust's internal control over financial reporting.

Item 17.

<u>Disclosure of Securities Lending Activities for Closed-End Management Investment Companies</u>

Not applicable.

Item 18.

<u>Recovery of Erroneously Awarded Compensation</u>

(a) Not applicable.

(b) Not applicable.

Item 19.

<u>Exhibits</u>

(a) (1) Not applicable.

(a) (2) [Certification pursuant to Rule 30a-2(a) under the Investment Company Act of 1940 (17 CFR 270.30a-2(a)) is filed and attached hereto as Exhibit 99.CERT.](ex99cert.htm)

(a) (3) Not applicable.

(b) [Certification pursuant to Rule 30a-2(b) under the Investment Company Act of 1940 (17 CFR 270.30a-2(b)) is furnished and attached hereto as Exhibit 99.906CERT.](ex99906cert.htm)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Fidelity Salem Street Trust

---

| | |
|:---|:---|
| &nbsp;&nbsp; By: | &nbsp;&nbsp; <u>/s/Laura M. Del Prato</u> |
|  | &nbsp;&nbsp; Laura M. Del Prato |
|  | &nbsp;&nbsp; President and Treasurer (Principal Executive Officer) |
| &nbsp;&nbsp; Date: | &nbsp;&nbsp; October 23, 2025 |

---

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.

---

| | |
|:---|:---|
| &nbsp;&nbsp; By: | &nbsp;&nbsp; <u>/s/Laura M. Del Prato</u> |
|  | &nbsp;&nbsp; Laura M. Del Prato |
|  | &nbsp;&nbsp; President and Treasurer (Principal Executive Officer) |
| &nbsp;&nbsp; Date: | &nbsp;&nbsp; October 23, 2025 |

---

---

| | |
|:---|:---|
| &nbsp;&nbsp; By: | &nbsp;&nbsp; <u>/s/Stephanie Caron</u> |
|  | &nbsp;&nbsp; Stephanie Caron |
|  | &nbsp;&nbsp; Chief Financial Officer (Principal Financial Officer) |
| &nbsp;&nbsp; Date: | &nbsp;&nbsp; October 23, 2025 |

---

## Ex-99.Cert

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

<u>Exhibit EX-99.CERT</u>

I, Laura M. Del Prato, certify that:

1. I have reviewed this report on Form N-CSR of Fidelity Salem Street 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;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;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;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 upon such evaluation; and

&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;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;b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:

October 23, 2025

---

| |
|:---|
| &nbsp;&nbsp;<u>/s/Laura M. Del Prato</u> |
| &nbsp;&nbsp;Laura M. Del Prato |
| &nbsp;&nbsp;President and Treasurer (Principal Executive Officer) |

---

I, Stephanie Caron, certify that:

1. I have reviewed this report on Form N-CSR of Fidelity Salem Street 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;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; 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;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 upon such evaluation; and

&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;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;b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:

October 23, 2025

---

| |
|:---|
| &nbsp;&nbsp;<u>/s/Stephanie Caron</u> |
| &nbsp;&nbsp;Stephanie Caron |
| &nbsp;&nbsp;Chief Financial Officer (Principal Financial Officer) |

---

## Exhibit 99.906

<u>Exhibit EX-99.906CERT</u>

**Certification Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of title 18, United States Code)**

In connection with the attached Report of Fidelity Salem Street Trust (the "Trust") on Form N-CSR to be filed with the Securities and Exchange Commission (the "Report"), each of the undersigned officers of the Trust does hereby certify that, to the best of such officer's knowledge:

&nbsp;&nbsp;&nbsp;&nbsp;1. The Report fully complies with the requirements of 13(a) or 15(d) of the Securities Exchange Act of 1934; and

&nbsp;&nbsp;&nbsp;&nbsp;2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Trust as of, and for, the periods presented in the Report.

Dated: October 23, 2025

---

| |
|:---|
| &nbsp;&nbsp;<u>/s/Laura M. Del Prato</u> |
| &nbsp;&nbsp;Laura M. Del Prato |
| &nbsp;&nbsp;President and Treasurer (Principal Executive Officer) |

---

Dated: October 23, 2025

---

| |
|:---|
| &nbsp;&nbsp;<u>/s/Stephanie Caron</u> |
| &nbsp;&nbsp;Stephanie Caron |
| &nbsp;&nbsp;Chief Financial Officer (Principal Financial Officer) |

---

A signed original of this written statement required by Section 906, or other document authenticating, acknowledging, or otherwise adopting the signature that appears in typed form within the electronic version of this written statement required by Section 906, has been provided to the Trust and will be retained by the Trust and furnished to the Securities and Exchange Commission or its staff upon request.

<br>