X0508 4 2025-12-03 0000350894 SEI INVESTMENTS CO SEIC 0001059374 WEST ALFRED P JR 1 FREEDOM VALLEY DRIVE OAKS PA 19456 true true Executive Chairman false Common Stock 2025-12-03 4 M 0 30000 53.34 A 6967582 D Common Stock 2025-12-03 4 S 0 24770 80.87 D 6942812 D STOCK OPTION (RIGHT TO PURCHASE) 53.34 2025-12-03 4 M 0 30000 D 2022-12-08 2025-12-08 STOCK OPTION (RIGHT TO PURCHASE) 30000 0 D Represents the weighted average of a range of sale prices from $80.70 to $81.04. The reporting person undertakes to provide to the Staff of the Securities and Exchange Commission, the Company, or any stockholder of the Company, upon request, full information regarding the number of shares sold at each separate price. Received as employment compensation. /s/ Alfred P. West, Jr., by Diane Gallagher, attorney in fact 2025-12-05