| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Sams Louise S | Director | C/O COSTAR GROUP, INC., 1201 WILSON BLVD., ARLINGTON | /s/ Gene Boxer, Attorney-in-Fact | 11 Sep 2025 | 0001796961 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | CSGP | Common Stock, par value $0.01 per share | Award | $0 | +3,291 | +20% | $0.000000 | 19,409 | 09 Sep 2025 | Direct |