CoStar Group CFO Christian M. Lown Sells 5,597 Shares at $29.36 per Share

Christian M. Lown, Chief Financial Officer of CoStar Group, Inc., sold 5,597 shares of common stock on July 1, 2026, at a price of $29.36 per share. Following this transaction, Lown's remaining holdings in the company amount to 129,653 shares. The filing is a Form 4 disclosure required by Section 16 of the Securities Exchange Act, which mandates that officers, directors, and principal shareholders report their transactions in company stock. The transaction was coded as "F" (equity swap) and "D" (disposed), indicating a sale of shares. The filing was signed by attorney-in-fact Lisa M. Tanzi on July 6, 2026. This represents a routine insider trading disclosure for a corporate officer's stock sale activity.