Annual Report by Investment Company (Form N-CSR)

AG Assured Guaranty

1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

AMG ETF Trust (the "Trust") is an open-endmanagement investment company, organized as a Massachusetts business trust, and registered under the Investment Company Act of 1940, as amended (the "1940 Act"). The Trust may offer a number of different funds that have distinct investment management objectives, strategies, risks, and policies. Currently, the Trust only offers AMG GW&K Muni Income ETF (the "Fund"). Shares of the Fund are listed and traded on the NYSE Arca, Inc. (the "Exchange") under the symbol: MUNX. The Fund commenced operations on October 29, 2025.

The Fund's financial statements are prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"), including accounting and reporting guidance pursuant to Accounting Standards Codification Topic 946 applicable to investment companies. U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates and such differences could be material. The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements:

a. VALUATION OF INVESTMENTS

Fixed income securities purchased with a remaining maturity exceeding 60 days are valued at the evaluated bid price provided by an authorized pricing service or, if an evaluated price is not available, by reference to other securities which are considered comparable in credit rating, interest rate, due date and other features (generally referred to as "matrix pricing") or other similar pricing methodologies.

Fixed income securities purchased with a remaining maturity of 60 days or less are valued at amortized cost, provided that the amortized cost value is approximately the same as the fair value of the security valued without the use of amortized cost. Investments in other open-endregistered investment companies are valued at their end of day net asset value per share.

The Fund's portfolio investments are generally valued based on independent market quotations or prices or, if none, "evaluative" or other market based valuations provided by third party pricing services. Pursuant to Rule 2a-5under the 1940 Act, the Fund's Board of Trustees (the "Board") designated AMG Funds LLC (the "Investment Manager") as the Fund's Valuation Designee to perform the Fund's fair value determinations. Such determinations are subject to Board oversight and certain reporting and other requirements intended to ensure that the Board receives the information it needs to oversee the Investment Manager's fair value determinations.

Under certain circumstances, the value of certain Fund portfolio investments may be based on an evaluation of fair value, pursuant to procedures established by the Investment Manager and under the general supervision of the Board. The Fund may use the fair value of a portfolio investment to calculate its net asset value ("NAV") in the event that the market quotation, price or market based valuation for the portfolio investment is not readily available or otherwise not determinable pursuant to the Fund's valuation procedures, if the Investment Manager believes the quotation, price or market based valuation to be unreliable, or in certain other circumstances. When determining the fair value of an investment, the Investment Manager seeks to determine the price that the Fund might reasonably expect to

receive from current sale of that portfolio investment in an arms-length transaction. Fair value determinations shall be based upon consideration of all available facts and information, including, but not limited to (i) attributes specific to the investment; (ii) fundamental and analytical data relating to the investment; and (iii) the value of other comparable securities or relevant financial instruments, including derivative securities, traded on other markets or among dealers.

The values assigned to fair value portfolio investments are based on available information and do not necessarily represent amounts that might ultimately be realized in the future, since such amounts depend on future developments inherent in long-term investments. Because of the inherent uncertainty of valuation, those estimated values may differ significantly from the values that would have been used had a ready market for the investments existed, and the differences could be material. The Board will be presented with quarterly reports, as of the most recent quarter end, summarizing all fair value activity, material fair value matters that occurred during the quarter, and all outstanding securities fair valued by the Fund. Additionally, the Board will be presented with an annual report that assesses the adequacy and effectiveness of the Investment Manager's process for determining the fair value of the Fund's investments.

U.S. GAAP defines fair value as the price that a fund would receive to sell an asset or pay to transfer a liability in an orderly transaction between market participants at the measurement date. U.S. GAAP also establishes a framework for measuring fair value, and a three level hierarchy for fair value measurements based upon the transparency of inputs to the valuation of an asset or liability. Inputs may be observable or unobservable and refer broadly to the assumptions that market participants would use in pricing the asset or liability. Observable inputs reflect the assumptions market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Fund. Unobservable inputs reflect the Fund's own assumptions about the assumptions that market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. Each investment is assigned a level based upon the observability of the inputs which are significant to the overall valuation.

The three-tier hierarchy of inputs is summarized below:

Level 1 - inputs are quoted prices in active markets for identical investments (e.g., equity securities, open-endinvestment companies)

Level 2 - other observable inputs (including, but not limited to: quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market corroborated inputs) (e.g., debt securities, government securities, foreign securities utilizing international fair value pricing, fair valued securities with observable inputs)

Level 3 - inputs are significant unobservable inputs (including the Fund's own assumptions used to determine the fair value of investments) (e.g., fair valued securities with unobservable inputs)

Changes in inputs or methodologies used for valuing investments may result in a transfer in or out of levels within the fair value hierarchy. The inputs or methodologies used for valuing investments may not necessarily be an indication of the risk associated with investing in those investments.

b. SECURITY TRANSACTIONS

Security transactions are accounted for as of trade date. Realized gains and losses on securities sold are determined on the basis of identified cost.

c. INVESTMENT INCOME AND EXPENSES

Interest income, which includes amortization of premium and accretion of discount on debt securities, is accrued as earned. Interest income on foreign securities is recorded gross of any withholding tax. Other income and expenses are recorded on an accrual basis. Expenses that cannot be directly attributed to the Fund are apportioned among the Trust and other trusts or funds within the AMG Funds Family of Funds (collectively, the "AMG Funds Family") based upon their relative average net assets or number of shareholders.

d. DIVIDENDS AND DISTRIBUTIONS

Fund distributions resulting from net investment income will normally be declared and paid monthly. Fund distributions resulting from net realized capital gains, if any, will normally be declared and paid annually in December. Distributions to shareholders are recorded on the ex-dividenddate. Distributions are determined in accordance with federal income tax law, which may differ from net investment income and net realized capital gains for financial statement purposes (U.S. GAAP). Differences may be permanent or temporary. Permanent differences are reclassified among capital accounts in the financial statements to reflect their tax character. Permanent book and tax basis differences, if any, relating to shareholder distributions will result in reclassifications to paid-incapital. Temporary differences arise when certain items of income, expense and gain or loss are recognized in different periods for financial statement and tax purposes; these differences will reverse at some time in the future. The Fund had no permanent or temporary differences.

The tax character of distributions paid during the fiscal period ended December 31, 2025 was as follows:

As of December 31, 2025, the components of distributable earnings (excluding unrealized appreciation/depreciation) on a tax basis consisted of:

At December 31, 2025, the cost of investments and the aggregate gross unrealized appreciation and depreciation for federal income tax purposes were as follows:

e. FEDERAL TAXES

The Fund intends to qualify as an investment company and intends to comply with the requirements under Subchapter M of the Internal Revenue Code of 1986, as amended (the "Code"), and to distribute substantially all of its taxable income and gains to its shareholders and to meet certain diversification and income requirements with respect to investment companies. The Investment Manager has analyzed the Fund's tax positions taken on federal income tax returns as of December 31, 2025, and has concluded that no provision for federal income tax is required in the Fund's financial statements. Additionally, the Investment Manager is not aware of any tax position for which it is reasonably possible that the total amounts of unrecognized tax benefit/detriment will change materially in the next twelve months.

f. CAPITAL LOSS CARRYOVERS AND DEFERRALS

As of December 31, 2025, the Fund had capital loss carryovers for federal income tax purposes as shown in the following chart. These amounts may be used to offset future realized capital gains indefinitely, and retain their character as short-term and/or long-term.

¹ Commencement of operations was October 29, 2025.

h. REPURCHASE AGREEMENTS

The Fund may enter into third-party and bilateral repurchase agreements for temporary cash management purposes. The value of the underlying collateral, including accrued interest, must equal or exceed the value of the repurchase agreements during the term of the agreement. The underlying collateral for all repurchase agreements is held by the Fund's custodian or at the Federal Reserve Bank. If the seller defaults and the value of the collateral declines, or if bankruptcy proceedings commence with respect to the seller of the security, realization of the collateral by the Fund may be delayed or limited.

At December 31, 2025, the market value of repurchase agreements outstanding was $154,000.

2. AGREEMENTS AND TRANSACTIONS WITH AFFILIATES

The Trust has entered into an investment management agreement under which the Investment Manager, a subsidiary and the U.S. wealth platform of Affiliated Managers Group, Inc. ("AMG"), serves as investment manager to the Fund and is responsible for the Fund's overall administration and operations. The Investment Manager selects and recommends, subject to the approval of the Board and, in certain circumstances, shareholders, the subadviser for the Fund and monitors the subadviser's investment performance, security holdings and investment strategies. The Fund's investment portfolio is managed by GW&K Investment Management, LLC ("GW&K"), who serves as subadviser pursuant to a subadvisory agreement with the Investment Manager. AMG indirectly owns a majority interest in GW&K.

The Trust, on behalf of the Fund, has entered into a second amended and restated administration agreement (the "Administration Agreement") under which the Investment Manager serves as the Fund's administrator (the "Administrator") and is responsible for certain aspects of managing the Fund's operations, including administration and shareholder services to the Fund.

The Investment Manager is paid directly by the Fund for its investment management and administration services via a unitary fee that is based on average daily net assets and payable under the investment management agreement (the "Unitary Fee"). The Fund does not pay a separate fee under the Administration Agreement. For the period October 29, 2025 (commencement of operations) to December 31, 2025, the Fund paid a Unitary Fee at the annual rate of 0.29% of the average daily net assets of the Fund.

The Board provides supervision of the affairs of the Trust and other trusts within the AMG Funds Family. The Trustees of the Trust who are not affiliated with the Investment Manager receive an annual retainer and per meeting fees for regular, special and telephonic meetings, and they are reimbursed for out-of-pocketexpenses incurred while carrying out their duties as Board members. The

Chairman of the Board and the Audit Committee Chair receive additional annual retainers. Certain Trustees and Officers of the Fund are Officers and/or Directors of the Investment Manager, AMG and/or the Distributor.

Pursuant to the Administration Agreement, the Investment Manager has undertaken that it will pay all of the ordinary operating expenses of the Fund except for certain excluded expenses as defined in the current prospectus. The fees paid to GW&K for services as subadviser and to the Trustees who are not affiliated with the Investment Manager for supervision of the Trust are paid out of the Unitary Fee the Investment Manager receives from the Fund and do not increase the expenses of the Fund.

The Securities and Exchange Commission (the "SEC") granted an exemptive order that permits certain eligible funds in the AMG Funds Family to lend and borrow money for certain temporary purposes directly to and from other eligible funds in the AMG Funds Family. Participation in this interfund lending program is voluntary for both the borrowing and lending funds, and an interfund loan is only made if it benefits each participating fund. The Administrator manages the program according to procedures approved by the Board, and the Board monitors the operation of the program. An interfund loan must comply with certain conditions set out in the exemptive order, which are designed to assure fairness and protect all participating funds. The interest earned and interest paid on interfund loans are included on the Statement of Operations as interest income and interest expense, respectively. At December 31, 2025, the Fund had no interfund loans outstanding. For the period October 29, 2025 (commencement of operations) to December 31, 2025, the Fund did not lend or borrow pursuant to the interfund lending program.

The "Receivable from Affiliate" on the Statement of Assets and Liabilities represents the amount owed by the Investment Manager for expenses paid by the Fund on behalf of the Investment Manager.

3. DISTRIBUTOR

The Fund is distributed by Foreside Fund Services, LLC, a wholly owned subsidiary of Foreside Financial Group, LLC (dba ACA Group) (the "Distributor"). The Distributor serves as the distributor and principal underwriter for the Fund and is a registered broker-dealer and member of the Financial Industry Regulatory Authority, Inc. ("FINRA"). The Distributor reviews and approves orders by Authorized Participants to create and redeem shares in Creation Units. No compensation is payable by the Fund to the Distributor for such distribution services. However, the Investment Manager has entered into an agreement with the Distributor under which it makes payments to the Distributor in consideration for its services under the Distribution Agreement. The payments made by the Investment Manager to the Distributor do not represent an additional expense to the Fund.

4. PURCHASES AND SALES OF SECURITIES

Purchases and sales of securities (excluding short-term securities and U.S. Government Obligations) for the fiscal period ended December 31, 2025, were $12,128,163 and $1,855,747, respectively.

The Fund had no purchases or sales of U.S. Government Obligations during the period ended December 31, 2025.

5. SEGMENT REPORTING

The Fund operates through a single operating and reporting segment to achieve its investment objective as reflected in the Fund's prospectus. The Chief Operating Decision Makers ("CODM") are the Fund's president and chief financial officer. The CODM assesses the performance and makes operating decisions for the Fund primarily based on the Fund's changes in net assets resulting from operations. In addition to other factors and metrics, the CODM utilizes the Fund's net assets, total return, and ratios of net and gross expenses to average net assets as key metrics in reviewing the performance of the Fund. As the Fund's operations comprise a single reporting segment, the segment assets are reflected on the accompanying Statement of Assets and Liabilities as "Total assets" and the significant segment expenses are listed on the Statement of Operations.

6. FUND RISKS

In the normal course of business, the Fund invests in securities or other instruments and may enter into certain transactions, and such activities subject the Fund to various risks. The value of securities or other instruments may also be affected by various factors, including, without limitation: (i) the general economy; (ii) the overall market; or (iii) price fluctuations. Please refer to the Fund's current prospectus for additional information about the Fund's principal risks.

Exchange-Traded Fund ("ETF") Structure Risks: The Fund is structured as an ETF and is subject to special risks, including:

Not Individually Redeemable: Shares are not individually redeemable by retail investors and may be redeemed from the Fund only by Authorized Participants at NAV in large blocks known as "Creation Units." An Authorized Participant may incur brokerage costs purchasing enough shares to constitute a Creation Unit.

Trading Issues: An active trading market for the Fund's shares may not be developed or maintained. Trading in shares on the Exchange may be halted due to market conditions or for reasons that, in the view of the Exchange, make trading in shares inadvisable, such as extraordinary market volatility. There can be no assurance that shares will continue to meet the listing requirements of the Exchange. If the Fund's shares are traded outside a collateralized settlement system, the number of financial institutions that can act as Authorized Participants that can post collateral on an agency basis is limited, which may limit the market for the Fund's shares. In addition, there may be a limited number of market makers and/or liquidity providers in the marketplace. To the extent the foregoing or either of the following events occur, shares may trade at a material discount to NAV and possibly face delisting: (i) Authorized Participants exit the business or otherwise become unable to process creation and/or redemption orders and no other Authorized Participants step forward to perform these services, or (ii) market makers and/or liquidity providers exit the business or significantly reduce their business activities and no other entities step forward to perform their functions.

Market Price Variance Risk: The market price of the Fund's shares will fluctuate in response to changes in NAV and supply and demand for shares and will include a

"bid-askspread" charged by the exchange specialists, market makers or other participants that trade the particular security. There may be times when the market price and the NAV vary significantly. This means that shares may trade at a discount or premium to NAV.

Market Trading Risk: The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. Any of these factors, among others, may lead to the Fund's shares trading at a premium or discount to NAV.

Fluctuation of Net Asset Value Risk: The NAV of the Fund's shares will generally fluctuate with changes in the market value of the Fund's holdings. The market prices of the Fund's shares will generally fluctuate in accordance with changes in NAV as well as the relative supply of and demand for the Fund's shares on the Exchange. The Investment Manager cannot predict whether the shares will trade below, at or above their NAV. Price differences may be due, because of, among other factors, the fact that supply and demand forces at work in the secondary trading market for the Fund's shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund's holdings trading individually or in the aggregate at any point in time.

Authorized Participant Concentration Risk: Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and no Authorized Participant is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units, Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.

Market Risk: Market prices of investments held by the Fund may fall rapidly or unpredictably due to a variety of factors, including economic, political, or market conditions, or other factors including terrorism, war, natural disasters and the spread of infectious illness or other public health issues, including epidemics or pandemics, or in response to events that affect particular industries or companies.

Management Risk: Because the Fund is an actively managed investment portfolio, security selection or focus on securities in a particular style, market sector or group of companies may cause the Fund to incur losses or underperform relative to its benchmarks or other funds with a similar investment objective. There can be no guarantee that GW&K's investment techniques and risk analysis will produce the desired result.

Debt Securities Risk: The value of a debt security changes in response to various factors, including, for example, market-related factors, such as changes in interest rates or changes in the actual or perceived ability of an issuer to meet its obligations. Investments in debt securities are subject to, among other risks, credit risk, interest rate risk, extension risk, prepayment risk and liquidity risk.

Interest Rate Risk: Fixed coupon payments (cash flows) of bonds and debt securities may become less competitive with the market in periods of rising interest rates and cause bond prices to decline. During periods of increasing interest rates, the Fund may experience high levels of volatility and shareholder redemptions, and may have to sell securities at times when it would otherwise not do so, and at unfavorable prices, which could reduce the returns of the Fund.

Credit Risk: The issuer of bonds or other debt securities may be unable or unwilling, or may be perceived as unable or unwilling, to make timely interest or principal payments or otherwise honor its obligations. Changes in an issuer's financial strength, credit rating or the market's perception of an issuer's creditworthiness may also affect the value of the Fund's investment in that issuer.

Municipal Market Risk: Factors unique to the municipal bond market may negatively affect the value of municipal bonds. These factors include political or legislative changes, and uncertainties related to the tax status of the securities and the rights of investors in the securities. The Fund may invest in a group of municipal obligations that are related in such a way that an economic, business, or political development affecting one would also affect the others.

Changing Distribution Level Risk: The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund's income or net capital gains arising from its investments may reduce its distribution level.

Prepayment Risk: A debtor may exercise its right to pay back a bond or other debt security earlier than expected or required during periods of decreasing interest rates.

Extension Risk: During periods of rising interest rates, a debtor may pay back a bond or other fixed income security slower than expected or required, and the value of such security may fall.

Reinvestment Risk: The Fund may have difficulty reinvesting payments from debtors and may receive lower rates than from its original investments.

High Yield Risk: Below investment grade debt securities and unrated securities of similar credit quality (commonly known as "junk bonds" or "high yield securities") may be subject to greater levels of interest rate, credit, liquidity, and market risk than higher-rated securities. These securities are considered predominately speculative with respect to the issuer's continuing ability to make principal and interest payments.

Inflation/Deflation Risk: Inflation risk is the risk that the value of assets or income from investments will be worth less in the future. Inflation rates may change frequently and drastically as a result of various factors and the Fund's investments may not keep pace with inflation, which may result in losses to Fund investors or adversely affect the real value of shareholders' investments in the Fund. As inflation rates increase, fixed income securities markets may experience heightened levels of interest rate volatility and liquidity risk. Deflation risk is the risk that the prices throughout the economy decline over time - the opposite of inflation. Deflation may have an adverse effect on the creditworthiness of issuers

and may make issuer default more likely, which may result in a decline in the value of the Fund's portfolio.

Sector Risk: Issuers and companies that are in similar industry sectors may be similarly affected by particular economic or market events; to the extent the Fund has substantial holdings within a particular sector, the risks associated with that sector increase. A portion of the Fund's assets may be invested in fixed income securities that would tend to respond similarly to particular economic or political developments or the interest on which is based on revenues or otherwise related to similar types of projects. An example would be securities of issuers whose revenues are paid from similar types of projects, such as utilities or transportation.

Liquidity Risk: The Fund may not be able to dispose of particular investments, such as illiquid securities, readily at favorable times or prices or the Fund may have to sell them at a loss.

New Fund Risk: The Fund is a new fund, which may result in additional risk. There can be no assurance that the Fund will grow to an economically viable size, in which case the Fund may cease operations. In such an event, investors may be required to liquidate or transfer their investments at an inopportune time. In addition, until the Fund achieves sufficient scale, a Fund shareholder may experience proportionally higher Fund expenses than would be experienced by shareholders of a fund with a larger asset base.

7. COMMITMENTS AND CONTINGENCIES

Under the Trust's organizational documents, its Trustees and Officers are indemnified against certain liabilities arising out of the performance of their duties to the Trust. In addition, in the normal course of business, the Fund may enter into contracts and agreements that contain a variety of representations and warranties, which provide general indemnifications. The maximum exposure to the Fund under these arrangements is unknown, as this would involve future claims that may be made against the Fund that have not yet occurred. However, the Fund expects the risks of loss to be remote.

8. MASTER NETTING AGREEMENTS

The Fund may enter into master netting agreements with its counterparties for repurchase agreements, which provide the right, in the event of default (including bankruptcy or insolvency) for the non-defaultingparty to liquidate the collateral and calculate net exposure to the defaulting party or request additional collateral. For financial reporting purposes, the Fund does not offset financial assets and financial liabilities that are subject to master netting agreements in the Statement of Assets and Liabilities.

9. RECENT ACCOUNTING STANDARDS UPDATE

In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) 2023-09Income 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. The Fund incorporated the provisions of the ASU, and there was no material impact to the Fund's financial statements.

10. SUBSEQUENT EVENTS

The Fund has determined that no material events or transactions occurred through the issuance date of the Fund's financial statements which require an additional disclosure in or adjustment of the Fund's financial statements.

AMG GW&K Muni Income ETF hereby designates the maximum amount allowable of its net taxable income as qualified dividends as provided in the Jobs and Growth Tax Relief Reconciliation Act of 2003. The 2025 Form 1099-DIVyou receive for the Fund will show the tax status of all distributions paid to you during the year.

Pursuant to section 852 of the Internal Revenue Code of 1986, as amended, AMG GW&K Muni Income ETF hereby designates $0 as a capital gain distribution with respect to the taxable year ended December 31, 2025, or if subsequently determined to be different, the net capital gains of such fiscal year.