X0306 4 2022-01-12 0 0001819928 DoubleVerify Holdings, Inc. DV 0001853874 McLaughlin Matthew F. C/O DOUBLEVERIFY HOLDINGS, INC. 233 SPRING STREET NEW YORK NY 10013 0 1 0 0 Chief Operating Officer Common Stock 2022-01-12 4 S 0 29934 27.8619 D 720822 I By Trust Common Stock 2022-01-12 4 S 0 5066 28.6785 D 715756 I By Trust Common Stock 2022-01-13 4 S 0 31783 27.6935 D 683973 I By Trust Common Stock 2022-01-13 4 S 0 3217 28.0919 D 680756 I By Trust The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 10, 2021. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $27.45 to $28.41, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. Represents shares held by The McLaughlin Family Trust for which Mr. McLaughlin is a trustee. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $28.49 to $29.31, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $27.04 to $28.03, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $28.04 to $28.23, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. /s/ Andrew E. Grimmig, as Attorney-in-Fact for Matthew F. McLaughlin 2022-01-14