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: 2026-05-01 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: COSTAR GROUP, INC. (CSGP) CIK: 0001057352 --- Reporting Owner --- Name: FLORANCE ANDREW C CIK: 0001066061 Role: Director, Officer (President and CEO) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock, par value $0.01 per share Date: 2026-05-01 | Code: P (Open market purchase) Shares: +68,330 | Price: $35.17 Total Value: $2,403,166.10 Shares Owned After: 1,719,765.03 | Ownership: D (Direct) Footnotes: [F1] Average based on sales prices ranging from $34.67 to $35.67. [Transaction #2] Security: Common Stock, par value $0.01 per share Date: 2026-05-01 | Code: P (Open market purchase) Shares: +3,100 | Price: $35.82 Total Value: $111,042.00 Shares Owned After: 1,722,865.03 | Ownership: D (Direct) Footnotes: [F2] Average based on sales prices ranging from $35.68 to $36.00. --- Footnotes (Complete Index) --- F1: Average based on sales prices ranging from $34.67 to $35.67. F2: Average based on sales prices ranging from $35.68 to $36.00. --- Signature --- /s/ /s/ Gene Boxer, Attorney-in-Fact (2026-05-04)