Results of Operations and Financial Condition. On July 30, 2026, Affiliated Managers Group, Inc. (the “Company”) issued a press release setting forth its financial and operating results for the quarter ended June 30, 2026. A copy of the press release is furnished as Exhibit 99.1 hereto, except for such portions which are filed, as noted below under

Other Events. The press release announced that the Company’s Board of Directors authorized and declared a quarterly dividend of $0.01 per share of common stock, payable August 24, 2026 to stockholders of record as of the close of business on August 10, 2026.

Entry into a Material Definitive Agreement. On June 9, 2026, Affiliated Managers Group, Inc. (the “Company”) entered into a Fourth Amended and Restated Credit Agreement (the “Revolving Credit Agreement”), providing for a $1.25 billion senior unsecured multicurrency revolving credit facility maturing on June 9, 2031, with Bank of America, N.A., as administrative agent, letter of credit issuer and swingline lender, and the other lending institutions from time to time party thereto, which amende…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information contained in

Other Events. The press release announced that the Company’s Board of Directors authorized and declared a quarterly dividend of $0.01 per share of common stock, payable May 26, 2026 to stockholders of record as of the close of business on May 11, 2026.

Results of Operations and Financial Condition. On May 1, 2026, Affiliated Managers Group, Inc. (the “Company”) issued a press release setting forth its financial and operating results for the quarter ended March 31, 2026. A copy of the press release is furnished as Exhibit 99.1 hereto, except for such portions which are filed, as noted below under

Director — G. Staley Cates: Appointment of G. Staley Cates to the Board of Directors.

President and Chief Operating Officer — Thomas M. Wojcik: Mr. Wojcik is stepping down as President and Chief Operating Officer with a significant severance package.

Results of Operations and Financial Condition. On February 12, 2026, Affiliated Managers Group, Inc. (the “Company”) issued a press release setting forth its financial and operating results for the quarter and year ended December 31, 2025. A copy of the press release is furnished as Exhibit 99.1 hereto, except for such portions which are filed, as noted below under

Other Events. The press release announced that the Company’s Board of Directors authorized and declared a quarterly dividend of $0.01 per share of common stock, payable March 9, 2026 to stockholders of record as of the close of business on February 23, 2026. The press release further announced that the Board of Directors authorized an additional share repurchase program. Under this program, the Company may repurchase up to 4.2 million shares of its issued and outstanding shares of common stoc…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information contained in

Entry into a Material Definitive Agreement. On December 11, 2025, Affiliated Managers Group, Inc. (the “Company”) completed the issuance and sale of $425,000,000 aggregate principal amount of the Company’s 5.500% Senior Notes due 2036 (the “Securities”). The Securities were issued pursuant to a senior notes indenture, dated as of June 5, 2020 (the “Base Indenture”), as supplemented by the third supplemental indenture thereto, dated as of December 11, 2025 (the “Third Supplemental Indenture” a…

Other Events. On December 8, 2025, Affiliated Managers Group, Inc. (the “Company”) delivered a notice of redemption (the “Redemption Notice”) for all of the outstanding 5.15% Convertible Trust Preferred Securities due 2037 of AMG Capital Trust II (the “Preferred Securities”), which were issued pursuant to the Amended and Restated Declaration of Trust, dated as of October 17, 2007, by and among the Company, U.S. Bank Trust Company, National Association, as property trustee and institutional ad…

Results of Operations and Financial Condition. On November 3, 2025, Affiliated Managers Group, Inc. (the “Company”) issued a press release setting forth its financial and operating results for the quarter ended September 30, 2025. A copy of the press release is furnished as Exhibit 99.1 hereto, except for such portions which are filed, as noted below under

Other Events. The press release announced that the Company’s Board of Directors authorized and declared a quarterly dividend of $0.01 per share of common stock, payable November 28, 2025 to stockholders of record as of the close of business on November 13, 2025.

Director — Marcy Engel: The filing announces the appointment of a new independent director and the retirement of a sitting director, which constitutes a routine board composition change rather than a loss of senior executive management.

Other Events. The press release announced that the Company’s Board of Directors authorized and declared a quarterly dividend of $0.01 per share of common stock, payable August 25, 2025 to stockholders of record as of the close of business on August 11, 2025.

Results of Operations and Financial Condition. On July 31, 2025, Affiliated Managers Group, Inc. (the “Company”) issued a press release setting forth its financial and operating results for the quarter ended June 30, 2025. A copy of the press release is furnished as Exhibit 99.1 hereto, except for such portions which are filed, as noted below under

President — Thomas M. Wojcik: The filing discloses the internal promotion of the COO to President, a standard succession step that is not a departure.

Other Events. The press release announced that the Company’s Board of Directors authorized and declared a quarterly dividend of $0.01 per share of common stock, payable June 2, 2025 to stockholders of record as of the close of business on May 19, 2025.

Results of Operations and Financial Condition. On May 8, 2025, Affiliated Managers Group, Inc. (the “Company”) issued a press release setting forth its financial and operating results for the quarter ended March 31, 2025. A copy of the press release is furnished as Exhibit 99.1 hereto.

Other Events. On March 7, 2025, Affiliated Managers Group, Inc. (the “Company”) filed a prospectus supplement to extend the Company’s $500 million Equity Distribution Program (as defined below), following the required filing of a new shelf registration statement on Form S-3 with the Securities and Exchange Commission on February 28, 2025. This prospectus supplement superseded and replaced the Company’s prior prospectus supplement filed on May 27, 2022, which was filed pursuant to the Company’…

Results of Operations and Financial Condition. On February 6, 2025, Affiliated Managers Group, Inc. (the “Company”) issued a press release setting forth its financial and operating results for the quarter and year ended December 31, 2024. A copy of the press release is furnished as Exhibit 99.1 hereto, except for such portions which are filed, as noted below under

Other Events. The press release announced that the Company’s Board of Directors authorized and declared a quarterly dividend of $0.01 per share of common stock, payable March 4, 2025 to stockholders of record as of the close of business on February 18, 2025.

Director — Reuben Jeffery III: The filing discloses the retirement of a director, which is an orderly succession event rather than a sudden loss of a senior executive officer.