144 0001552213 XXXXXXXX LIVE 0000851520 EXPONENT, INC. 000-18655 149 COMMONWEALTH DRIVE MENLO PARK CA 94025 6503269400 CATHERINE CORRIGAN Director Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

3909 264052.95 49254339 04/15/2026 NASDAQ Common 04/15/2026 Exercise of Stock Options Issuer N 3909 04/15/2026 Cash N 10b5-1 Sales for CATHERINE CORRIGAN

149 COMMONWEALTH DRIVE MENLO PARK CA 94025

Common 03/16/2026 3912 264013.84 10b5-1 Sales for CATHERINE CORRIGAN

149 COMMONWEALTH DRIVE MENLO PARK CA 94025

Common 02/17/2026 3920 263239.62 04/15/2026 05/15/2025 /s/ Catherine Corrigan