144 0001955607 XXXXXXXX LIVE 0001842718 INTEGRAL AD SCIENCE HOLDING CORP. 001-40557 99 WALL STREET #1950 NEW YORK NY 10005 (646) 278-4871 SECOR TANIA Officer Common Fidelity Brokerage Services LLC

900 Salem Street Smithfield RI 02917

7889 87384.09 161364929 09/09/2024 NASDAQ Common 09/05/2024 Restricted Stock Vesting Issuer N 7889 09/05/2024 Compensation N Tania R. Secor

12 E 49th Street 20th Floor New York NY 10017

Common 06/10/2024 6382 57553.51 Tania R. Secor

12 E 49th Street 20th Floor New York NY 10017

Common 07/08/2024 4564 44159.44 Tania R. Secor

12 E 49th Street 20th Floor New York NY 10017

Common 09/06/2024 6643 74691.90 Sale includes an amount necessary to cover a tax obligation resulting from the settlement of a vested equity award distribution. 09/09/2024 /s/ Gerardo Ibarra-Munoz, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Tania R. Secor