Form 4 Filing: Alpana Wegner Sells INTEGRAL AD SCIENCE HOLDING CORP. Shares Post-Merger

Alpana Wegner, Chief Financial Officer of INTEGRAL AD SCIENCE HOLDING CORP. (IAS), reported a disposition of 525,279 shares of common stock on December 23, 2025. The shares were sold at a price of $10.30 per share, resulting in a post-transaction share count of 0. This transaction occurred in connection with a merger, where each outstanding share of common stock was cancelled and converted into the right to receive $10.30 in cash. The disposed shares include 131,319 unvested restricted stock units (RSUs) that vested at the effective time of the merger and were converted into cash, as well as 393,960 RSUs that were cancelled and converted into cash awards. These cash awards will vest and be payable according to the original vesting schedules of the RSUs, subject to continued service.