Fidelity Aberdeen Street Trust 提交 N-CSR 半年度股东报告

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number   811-06440

Fidelity Aberdeen Street Trust

 (Exact name of registrant as specified in charter)

245 Summer St., Boston, MA 02210

 (Address of principal executive offices)       (Zip code)

Nicole Macarchuk, Secretary

245 Summer St.

Boston, Massachusetts  02210

(Name and address of agent for service)

Registrant's telephone number, including area code:

617-563-7000

Item 1.

Reports to Stockholders

This semi-annual shareholder report contains information about Fidelity® Multi-Asset Index Fund for the period March 1, 2026 to August 31, 2026. 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 [email protected].

What were your Fund costs for the last six months?

(based on hypothetical $10,000 investment)

Key Fund Statistics

(as of August 31, 2026)

What did the Fund invest in?
(as of August 31, 2026)

Item 2.

Code of Ethics

Not applicable.

Item 3.

Audit Committee Financial Expert

Not applicable.

Item 4.

Principal Accountant Fees and Services

Not applicable.

Item 5.

Audit Committee of Listed Registrants

Not applicable.

Item 6.  

Investments

(a)

Not applicable.

(b)

Not applicable

Item 7.

Financial Statements and Financial Highlights for Open-End Management Investment Companies

Fidelity® Multi-Asset Index Fund

Semi-Annual Report

August 31, 2026

Contents

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. © 2026 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, 2026 (Unaudited)

Showing Percentage of Net Assets

Legend

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.

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, 2026, 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.

Financial Statements (Unaudited)

Financial Highlights

Notes to Financial Statements

 (Unaudited)

For the period ended August 31, 2026

• 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. 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 portfolio management team, part of the investment adviser, serves as the chief operating decision maker (CODM) and directs the Fund's investments in accordance with its investment objective and policies, with support from others responsible for oversight functions. The information reviewed by the CODM is consistent with the Fund's 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:

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 period end is included at the end of the Fund's Schedule of Investments.

Investment Transactions and Income. For financial reporting purposes, the investment holdings and net asset value (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.

Dividend income for domestic securities is recorded on the ex-dividend date. Certain dividends from any foreign securities where the ex-dividend date may have passed are recorded as soon as a fund is informed of the ex-dividend date. Non-cash dividends, if any, are recorded at the fair market value of the securities received.

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. These differences may result in distribution reclassifications.

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:

• 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.

• 4. Fees and Other Transactions with Affiliates.

Management Fee. Fidelity Management & Research Company LLC (the investment adviser) and its affiliates 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 based on an annual management fee rate of the Fund's average net assets as presented in the table below.

Under the management contract, the investment adviser pays all other operating expenses, except fees and expenses of the independent Trustees, and certain miscellaneous 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 expenses to the extent annual operating expenses exceeded certain levels of average net assets.

The following operating expenses are excluded from this reimbursement as applicable: interest, certain taxes, fees and expenses of the independent Trustees, extraordinary expenses, acquired fund fees and expenses, brokerage commissions, and fees and expenses associated with the securities lending program.

During the period, this reimbursement reduced expenses as presented in the table below.

• 6. Distributions to Shareholders. 

Distributions to shareholders of each class were as follows:

• 7. Share Transactions.

Share transactions were as follows and may contain in kind transactions, automatic conversions between classes or exchanges between affiliated funds as applicable:

• 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.

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.

• 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.

1.728266.127

IDV-SANN-1026

Item 8.

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

See Item 7.

Item 9.

Proxy Disclosures for Open-End Management Investment Companies

See Item 7.

Item 10.

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

See Item 7.

Item 11.

Statement Regarding Basis for Approval of Investment Advisory Contract

See Item 7.

Item 12.

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

Not applicable.

Item 13.

Portfolio Managers of Closed-End Management Investment Companies

Not applicable.

Item 14.  

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

Not applicable.

Item 15.

Submission of Matters to a Vote of Security Holders

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

Item 16.

Controls and Procedures

(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.

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

Not applicable.

Item 18.

Recovery of Erroneously Awarded Compensation

(a)

Not applicable.

(b)

Not applicable.

Item 19.

Exhibits

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

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.