COSTAR GROUP, INC. (CSGP) · Insider Trading (Form 4) SEC Filing

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-07-31 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: COSTAR GROUP, INC. (CSGP) CIK: 0001057352 --- Reporting Owner --- Name: Rossmann Robin Jack CIK: 0002146463 Role: Officer (Chief Financial Officer) --- Derivative Transactions --- [Transaction #1] Security: Restricted Stock Units Date: 2026-07-31 | Code: A (Grant or award) Shares: +34,771 | Price: $0.00 Shares Owned After: 34,771 | Ownership: D (Direct) Footnotes: [F1] Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock. [F2] The restricted stock units vest in three equal installments on August 1, 2027, August 1, 2028 and August 1, 2029. [F2] The restricted stock units vest in three equal installments on August 1, 2027, August 1, 2028 and August 1, 2029. --- Footnotes (Complete Index) --- F1: Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock. F2: The restricted stock units vest in three equal installments on August 1, 2027, August 1, 2028 and August 1, 2029. --- Signature --- /s/ /s/ Gene Boxer, Attorney-in-Fact (2026-08-04)