X0609 4 2026-05-31 0001819928 DoubleVerify Holdings, Inc. DV 0001709574 Zagorski Mark false C/O DOUBLEVERIFY HOLDINGS, INC. 462 BROADWAY NEW YORK NY 10013 1 1 Chief Executive Officer 0 Common Stock 2026-05-31 5 J 0 E 416 8.25 A 547158 D Pursuant to the DoubleVerify Holdings, Inc. 2021 Employee Stock Purchase Plan (ESPP), the purchase price per share reported reflects a discount of 15% of the lesser of the share price at the first day of the offering period or the purchase date. /s/ Andrew E. Grimmig, as Attorney-in-Fact for Mark S. Zagorski 2026-06-03