X0306 4 2023-03-16 0001004434 AFFILIATED MANAGERS GROUP, INC. AMG 0001492280 Jeffery Reuben III C/O AFFILIATED MANAGERS GROUP, INC. 777 SOUTH FLAGLER DRIVE WEST PALM BEACH FL 33401 1 Common Stock 2023-03-16 4 P 0 3650 137.21 A 31726 D The price reflects the weighted average price of shares purchased on the open market; the individual transaction prices ranged from $136.89 to $138.03. Specific transaction details will be provided to the SEC upon request. /s/ Kavita Padiyar, Attorney-in-Fact 2023-03-17