Form 4 Filing for COSTAR GROUP, INC.

Lisa Ruggles, Senior VP of Global Operations at COSTAR GROUP, INC. (CSGP), reported a disposition of 2,977 shares of common stock on March 15, 2026. The transaction, coded as 'F', occurred at a price of $43.63 per share. Following this transaction, Ms. Ruggles directly owns 174,915 shares of the company's common stock. The closing price of the stock on the preceding business day was also $43.63, as noted in footnote F1.