CoStar Group President and CEO Andrew Florance purchased 71,430 shares. The investment totaled approximately $2.5 million. An SEC filing disclosed the transactions on May 4, 2026.

Florance executed the open-market trades on Friday, May 1. Average purchase prices were $35.17 and $35.82 per share. The purchase follows a substantial stock decline over the past year.

CoStar Group (CSGP) shares rose 2.8% in premarket trading on Monday following the disclosure. Investors view the move as a vote of confidence in the company's future outlook.