🕵️ Costar Group, Inc. ($CSGP)
SEC insider & ownership activity, last 12 months · CIK 1057352 · every row links its SEC filing
Over the last 12 months insiders sold $534K against $8.5M of open-market buying. Andrew C. Florance bought $7.5M (Feb–Aug). No red-flag 8-Ks in the window.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
4 buyers, $8.5M (7 lots) · 2 sellers, $534K (4 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Andrew C. Florance | 4 | $7.5M | 0 | – | Aug 4, 2026 |
| Frederick Saint | 1 | $907K | 0 | – | Mar 2, 2026 |
| Cann Cynthia Cammett | 0 | – | 2 | $274K | Aug 7, 2026 |
| John W. Hill | 0 | – | 2 | $260K | Aug 5, 2026 |
| Louise S. Sams | 1 | $48K | 0 | – | Mar 6, 2026 |
| Rachel C. Glaser | 1 | $45K | 0 | – | Mar 2, 2026 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Vanguard Portfolio Management | 9.1% | 13G | Apr 29, 2026 | filing ↗ | |
| Vanguard Capital Management | 7.5% | 13G | Apr 29, 2026 | filing ↗ | |
| BlackRock, Inc. | 7.5% | 13G | Apr 23, 2025 | filing ↗ | |
| Baron Capital Group, Inc. | 5.3% | 13G | Aug 14, 2026 | filing ↗ | |
| Ronald Baron | 5.3% | 13G | Aug 14, 2026 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| John W. Hill | $106K | Aug 5, 2026 | filing ↗ |
| John W. Hill | $152K | Nov 13, 2025 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Reg FD disclosure (7.01) | Aug 21, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 21, 2026 | filing ↗ |
| Earnings (2.02) | Jul 28, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jul 28, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jul 7, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jul 7, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jul 7, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jun 23, 2026 | filing ↗ |
| Shareholder vote (5.07) | Jun 23, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jun 23, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jun 23, 2026 | filing ↗ |
| Material agreement (1.01) | May 28, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | May 28, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 28, 2026 | filing ↗ |
| Earnings (2.02) | Apr 28, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Apr 28, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Apr 28, 2026 | filing ↗ |
| Officer/director changes (5.02) | Mar 15, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Mar 15, 2026 | filing ↗ |
| Earnings (2.02) | Feb 24, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Feb 24, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 24, 2026 | filing ↗ |
| Officer/director changes (5.02) | Feb 13, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 13, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jan 7, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 7, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 7, 2026 | filing ↗ |
| Earnings (2.02) | Oct 28, 2025 | filing ↗ |
| Reg FD disclosure (7.01) | Oct 28, 2025 | filing ↗ |