# EDGAR Filing Document

**Accession Number:** 0000880195
**File Stem:** 0000880195-25-000936
**Filing Date:** 2025-10
**Character Count:** 47252
**Document Hash:** ee6755ba2166a0d59657b9539758da5f
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000880195-25-000936.hdr.sgml**: 20251023

**ACCESSION NUMBER**: 0000880195-25-000936

**CONFORMED SUBMISSION TYPE**: N-CSRS

**PUBLIC DOCUMENT COUNT**: 20

**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 ABERDEEN STREET TRUST
- **CENTRAL INDEX KEY:** 0000880195

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 0331

**FILING VALUES:**
- **FORM TYPE:** N-CSRS
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-06440
- **FILM NUMBER:** 251411845

**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 INSTITUTIONAL INVESTORS TRUST
- **DATE OF NAME CHANGE:** 19920811

## Series and Classes Contracts Data

### Fidelity Multi-Asset Index Fund (Series ID: S000040658)

| Class ID   | Class Name                      | Ticker Symbol   |
|:---|:---|:---|
| C000126039 | Fidelity Multi-Asset Index Fund | FFNOX           |

?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>811-06440</u>

<u>Fidelity Aberdeen 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® Multi-Asset Index Fund<br> **Fidelity® Multi-Asset Index Fund : FFNOX** <br>|

---

This semi-annual shareholder report contains information about Fidelity® Multi-Asset 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® Multi-Asset Index Fund  | $4  | 0.08% |

---

**Key Fund Statistics**

(as of August 31, 2025)

---

| | |
|:---|:---|
| **KEY FACTS**  |  |
| Fund Size | $9136104769<br>|
| Number of Holdings | 7<br>|
| Portfolio Turnover | 15%<br>|

---

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

---

| | |
|:---|:---|
| Domestic Equity Funds | 51.0 |
| International Equity Funds | 34.0 |
| Bond Funds | 15.0 |
| Short-Term Investments and Net Other Assets (Liabilities) | 0.0 |

---

---

| |
|:---|
| **ASSET ALLOCATION (% of Fund's net assets)** |
| ![](img355_20250831_AA.jpg) <br>|

---

---

| |
|:---|
| Domestic Equity Funds - 51.0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |
| International Equity Funds - 34.0&nbsp;&nbsp;&nbsp;&nbsp;  |
| Bond Funds - 15.0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  |
| Short-Term Investments and Net Other Assets (Liabilities) - 0.0 |

---

---

| | |
|:---|:---|
| **TOP HOLDINGS**<br>**(% of Fund's net assets)**  |  |
| Fidelity 500 Index Fund | 41.0<br>|
| Fidelity International Index Fund | 24.0<br>|
| Fidelity Extended Market Index Fund | 10.0<br>|
| Fidelity Emerging Markets Index Fund | 10.0<br>|
| Fidelity U.S. Bond Index Fund | 7.0<br>|
| Fidelity Long-Term Treasury Bond Index Fund | 5.0<br>|
| Fidelity International Bond Index Fund | 3.0<br>|
|  | 100.0 |

---

---

| | | |
|:---|:---|:---|
| 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. |
| ![](img355_20250831_1.jpg)<br>| ![](img113940_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> 1.9914531.101 355-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® Multi-Asset Index Fund**

**Semi-Annual Report**

**August 31, 2025**

![](img114166_1.jpg)

![](img114166_2.jpg)

**Contents**

---

| |
|:---|
| **[Item 7: Financial Statements and Financial Highlights for Open-End Management Investment Companies (Semi-Annual Report)](#Sec_Item7_IDV-SANN_0)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Fidelity® Multi-Asset Index Fund](#Sub_Sec_Fund_355_IDV-SANN)** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **[Notes to Financial Statements](#Sub_Sec_NotestoFinancialStatements355_IDV-SANN)** |
| **[Item 8: Changes in and Disagreements with Accountants for Open-End Management Investment Companies](#Sec_Item8_IDV-SANN)** |
| **[Item 9: Proxy Disclosures for Open-End Management Investment Companies](#Sec_Item9_IDV-SANN)** |
| **[Item 10: Remuneration Paid to Directors, Officers, and others of Open-End Management Investment Companies](#Sec_Item10_IDV-SANN)** |
| **[Item 11: Statement Regarding Basis for Approval of Investment Advisory Contract](#Sec_Item11_IDV-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.

The index is a product of S&P Dow Jones Indices LLC or its affiliates ("SPDJI") and has been licensed for us by Fidelity. S&P®;, S&P 500®, US 500, The 500, iBoxx®, iTraxx® and CDX® are trademarks of S&P Global, Inc. or its affiliates ("S&P") and Dow Jones®; is a registered trademark of Dow Jones Trademark Holdings LLC ("Dow Jones"). The fund is not sponsored, endorsed, sold or promoted by SPDJI, Dow Jones, S&P, or their respective affiliates and none of such parties make any representation regarding the advisability of investing in such product(s) nor do they have any liability for any errors, omissions, or interruptions of the index or indices.

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® Multi-Asset Index Fund**

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

Showing Percentage of Net Assets

---

| | | |
|:---|:---|:---|
| &nbsp;&nbsp;**Bond Funds - 15.0%** | &nbsp;&nbsp;**Bond Funds - 15.0%** | &nbsp;&nbsp;**Bond Funds - 15.0%** |
|  | Shares | Value ($)<br>|
| Fidelity International Bond Index Fund (a) | 29269878 | 273380661 |
| Fidelity Long-Term Treasury Bond Index Fund (a) | 49803014 | 456693641 |
| Fidelity U.S. Bond Index Fund (a) | 61138178 | 640116728 |
| <br> **TOTAL BOND FUNDS**<br> (Cost $1,550,859,206) |  | **1370191030** |

---

---

| | | |
|:---|:---|:---|
| &nbsp;&nbsp;**Domestic Equity Funds - 51.0%** | &nbsp;&nbsp;**Domestic Equity Funds - 51.0%** | &nbsp;&nbsp;**Domestic Equity Funds - 51.0%** |
|  | Shares | Value ($)<br>|
| Fidelity 500 Index Fund (a) | 16649737 | 3742194851 |
| Fidelity Extended Market Index Fund (a) | 9267157 | 918097279 |
| <br> **TOTAL DOMESTIC EQUITY FUNDS**<br> (Cost $999,201,048) |  | **4660292130** |

---

---

| | | |
|:---|:---|:---|
| &nbsp;&nbsp;**International Equity Funds - 34.0%** | &nbsp;&nbsp;**International Equity Funds - 34.0%** | &nbsp;&nbsp;**International Equity Funds - 34.0%** |
|  | Shares | Value ($)<br>|
| Fidelity Emerging Markets Index Fund (a) | 72883051 | 913953459 |
| Fidelity International Index Fund (a) | 37423513 | 2192269382 |
| <br> **TOTAL INTERNATIONAL EQUITY FUNDS**<br> (Cost $2,136,062,563) |  | **3106222841** |

---

---

| | |
|:---|:---|
| <br> **TOTAL INVESTMENT IN SECURITIES - 100.0%**<br> (Cost $4,686,122,817)<br>| <br>**9136706001** |
| **NET OTHER ASSETS (LIABILITIES) - 0.0%**  | **(601232)** |
| **NET ASSETS - 100.0%** | **9136104769** |

---

**Legend**

(a) Affiliated Fund

**Affiliated Underlying Funds**

Fiscal year to date information regarding the Fund's investments in affiliated underlying funds is presented below. Exchanges between classes of the same affiliated underlying funds may occur. If an underlying fund changes its name, the name presented below is the name in effect at period end.

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| 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 |
| Fidelity 500 Index Fund | 3493094226 | 238061652 | 291079157 | 21193960 | 9754169 | 292363961 | 3742194851 | 16649737 |
| Fidelity Emerging Markets Index Fund | 837305683 | 24146467 | 80137227 | - | (6662598) | 139301134 | 913953459 | 72883051 |
| Fidelity Extended Market Index Fund | 850402135 | 58628308 | 80870469 | - | 1055136 | 88882169 | 918097279 | 9267157 |
| Fidelity International Bond Index Fund | 252083640 | 33945501 | 12005794 | 3017451 | (121791) | (520895) | 273380661 | 29269878 |
| Fidelity International Index Fund | 2024564172 | 131067288 | 232216086 | - | 25551904 | 243302104 | 2192269382 | 37423513 |
| Fidelity Long-Term Treasury Bond Index Fund | 423721615 | 75247670 | 22064919 | 8266772 | (9456599) | (10754126) | 456693641 | 49803014 |
| Fidelity U.S. Bond Index Fund | 590299462 | 82205076 | 34531306 | 10809215 | (1857003) | 4000499 | 640116728 | 61138178 |
|  | 8471470933 | 643301962 | 752904958 | 43287398 | 18263218 | 756574846 | 9136706001 |  |

---

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>** |  |  |  |  |
|  **Bond Funds** | 1370191030 | 1370191030 | - | - |
|  **Domestic Equity Funds** | 4660292130 | 4660292130 | - | - |
|  **International Equity Funds** | 3106222841 | 3106222841 | - | - |
| **Total Investments in Securities:** | 9136706001 | 9136706001 | - | - |

---

**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: |  |  |
| Affiliated issuers (cost $4,686,122,817) | $9136706001 |  |
| Total Investment in Securities (cost $4,686,122,817) |  | $9136706001 |
| Receivable for investments sold |  | 42881568 |
| Receivable for fund shares sold |  | 3170600 |
| Receivable from investment adviser for expense reductions |  | 151372 |
| **Total assets** |  | 9182909541 |
| **Liabilities** |  |  |
| Payable for investments purchased  | $43693188 |  |
| Payable for fund shares redeemed | 2355367 |  |
| Accrued management fee | 756217 |  |
| **Total liabilities** |  | 46804772 |
| **Net Assets**  |  | $9136104769 |
| Net Assets consist of: |  |  |
| Paid in capital |  | $4713033823 |
| Total accumulated earnings (loss) |  | 4423070946 |
| **Net Assets** |  | $9136104769 |
| **Net Asset Value**, offering price and redemption price per share ($9,136,104,769 ÷ 142,084,177 shares) |  | $64.30 |

---

---

| | | |
|:---|:---|:---|
| **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** |  |  |
| Dividends: |  |  |
| Affiliated issuers |  | $43287398 |
| **Expenses** |  |  |
| Management fee | $4256584 |  |
| Independent trustees' fees and expenses | 9751 |  |
| Total expenses before reductions | 4266335 |  |
| Expense reductions | (853952) |  |
| Total expenses after reductions |  | 3412383 |
| **Net Investment income (loss)** |  | 39875015 |
| **Realized and Unrealized Gain (Loss)** |  |  |
| Net realized gain (loss) on: |  |  |
| Investment Securities: |  |  |
| Affiliated issuers | 18263218 |  |
| Total net realized gain (loss) |  | 18263218 |
| Change in net unrealized appreciation (depreciation) on: |  |  |
| Investment Securities: |  |  |
| Affiliated issuers  | 756574846 |  |
| Total change in net unrealized appreciation (depreciation) |  | 756574846 |
| **Net gain (loss)** |  | 774838064 |
| **Net increase (decrease) in net assets resulting from operations** |  | $814713079 |

---

---

| | | |
|:---|:---|:---|
| **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) | $39875015 | $170078803 |
| &nbsp;&nbsp;Net realized gain (loss) | 18263218<br>| 348128473<br>|
| &nbsp;&nbsp;Change in net unrealized appreciation (depreciation) | 756574846 | 487522697<br>|
| &nbsp;&nbsp;**Net increase (decrease) in net assets resulting from operations** | 814713079<br>| 1005729973<br>|
| Distributions to shareholders | (139041681)<br>| (516236808)<br>|
| Share transactions |  |  |
| &nbsp;&nbsp;Proceeds from sales of shares | 368401197 | 604083711 |
| Reinvestment of distributions | 126025263<br>| 468431390<br>|
| &nbsp;&nbsp;Cost of shares redeemed | (504896237) | (1132820229) |
| **Net increase (decrease) in net assets resulting from share transactions** | (10469777)<br>| (60305128)<br>|
| &nbsp;&nbsp;**Total increase (decrease) in net assets** | 665201621<br>| 429188037<br>|
| **Net Assets** |  |  |
| &nbsp;&nbsp;Beginning of period | 8470903148 | 8041715111<br>|
| &nbsp;&nbsp;End of period | $9136104769 | $8470903148 |
| **Other Information** |  |  |
| Shares |  |  |
| &nbsp;&nbsp;Sold | 6122038 | 10240918 |
| Issued in reinvestment of distributions | 2315364<br>| 8189713<br>|
| &nbsp;&nbsp;Redeemed | (8512308) | (19138895) |
| &nbsp;&nbsp;Net increase (decrease) | (74906) | (708264) |

---

**Financial Highlights** 

**Fidelity® Multi-Asset 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  | $59.59 | $56.29 | $48.92 | $56.99 | $56.29 | $45.60 |
| Income from Investment Operations  |  |  |  |  |  |  |
| Net investment income (loss) B,C | .28  | 1.20  | 1.11  | .94  | 1.14  | .86  |
| Net realized and unrealized gain (loss)  | 5.42  | 5.81  | 7.99  | (5.65)  | 3.06  | 11.42  |
| Total from investment operations  | 5.70  | 7.01  | 9.10  | (4.71)  | 4.20  | 12.28  |
| Distributions from net investment income  | (.03)  | (1.24)  | (1.10)  | (.96)  | (1.14)  | (.88)  |
| Distributions from net realized gain  | (.95)  | (2.48)  | (.63)  | (2.40)  | (2.35)  | (.70)  |
| Total distributions  | (.99) D | (3.71) D | (1.73)  | (3.36)  | (3.50) D | (1.59) D |
| Net asset value, end of period  | $64.30 | $59.59 | $56.29 | $48.92 | $56.99 | $56.29 |
| **Total Return** E,F | 9.86% <br>| 12.82%  | 18.72%  | (8.43)%  | 7.07%  | 27.10%  |
| **Ratios to Average Net Assets** C,G,H |  |  |  |  |  |  |
| Expenses before reductions  | .10% I | .10%  | .10%  | .10%  | .10%  | .10%  |
| Expenses net of fee waivers, if any  | .08% I<br>| .08%  | .08%  | .08%  | .08%  | .08%  |
| Expenses net of all reductions, if any  | .08% I | .08%  | .08%  | .08%  | .08%  | .08%  |
| Net investment income (loss)  | .93% I | 2.03%  | 2.13%  | 1.89%  | 1.87%  | 1.73%  |
| **Supplemental Data** |  |  |  |  |  |  |
| Net assets, end of period (000 omitted) | $9136105 | $8470903 | $8041715 | $7185984 | $8314829 | $7597894 |
| Portfolio turnover rate J | 15% I<br>| 12%  | 10%  | 17%  | 28%  | 16%  |

---

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 distributions per share do not sum due to rounding.*

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.*

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*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 Multi-Asset Index Fund (the Fund) is a fund of Fidelity Aberdeen Street Trust (the Trust) and 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 Delaware statutory trust. Geode Capital Management, LLC serves as sub-adviser for the underlying stock funds.

The Fund is a fund of funds, and therefore invests in other funds instead of individual securities. The Fund invests primarily in a combination of Fidelity stock and bond index funds.

**2. 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 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:

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

**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 any underlying mutual funds or exchange-traded funds are recorded on the ex-dividend date.

**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 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 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** | $4573660943 |
| **Gross unrealized depreciation** | <u>(206702706)</u> |
| **Net unrealized appreciation (depreciation)** | <u>$4366958237</u> |
| **Tax cost** | <u>$4769747764</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.

**3. Purchases and Sales of Investments.**

Purchases and sales of securities, other than short-term securities and in-kind transactions, as applicable, are noted in the table below.

---

| | | |
|:---|:---|:---|
|  | **Purchases ($)** | **Sales ($)** |
| **Fidelity Multi-Asset Index Fund** | 643301962 | 752904958 |

---

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

**Management Fee.** Fidelity Management & Research Company LLC (the investment adviser) provides the Fund with investment management related services. For these services the Fund pays a monthly management fee to the investment adviser. The management fee is computed at an annual rate of .10% of the 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. The management fee is reduced by an amount equal to the fees and expenses paid by the Fund to the independent Trustees.

**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. Expense Reductions.** 

The investment adviser contractually agreed to reimburse the Fund to the extent annual operating expenses exceeded .08% 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 $853,867.

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 $85.

**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.

Funds do not invest in underlying mutual funds for the purpose of exercising management or control; however, investments by funds within their principal investment strategies may represent a significant portion of the underlying mutual fund's net assets. At the end of the period, certain Funds were the owners of record of 10% or more of the total outstanding shares of the following underlying mutual funds as shown below.

---

| | |
|:---|:---|
| **Fund**  | **Fidelity Multi-Asset Index Fund** |
| Fidelity International Bond Index Fund | 26% |

---

**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.

![](img114166_4.jpg)<br>

1.728266.126 IDV-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 Aberdeen 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 Aberdeen 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.](ex99.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.](ex99906.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 Aberdeen 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;

<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 Aberdeen 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 Aberdeen 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 Aberdeen 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>