X0609 4 2026-05-14 0 0001748824 Acadian Asset Management Inc. AAMI 0001730619 Trebbi Barbara false C/O ACADIAN ASSET MANAGEMENT INC. 200 STATE STREET, SUITE 601A BOSTON MA 02109 1 0 0 0 0 Common Stock 2026-05-14 4 M 0 3286 0 A 39057 D Restricted Stock Units 2026-05-14 4 M 0 3286 0 D Common Stock 3286 0 D Each restricted stock unit represents a right to receive one share of common stock of Acadian Asset Management Inc. On May 14, 2025, the reporting person was granted 3,286 restricted stock units vesting upon the earlier of May 14, 2026 and the date of the 2026 annual meeting of stockholders of Acadian Asset Management Inc. /s/ Richard J. Hart, By POA for Barbara Trebbi 2026-05-18