15 insiders reported 91 Form 4 transactions for COSTAR GROUP, INC. (CSGP) over the past 18 months (most recent 2026-08-10). Recent activity: Cann Cynthia Cammett (Chief Accounting Officer) Sell 4,788 shares, Hill John W (Director) Sell 3,500 shares, FLORANCE ANDREW C (Founder and CEO) Buy 83,300 shares, SAINT FREDERICK G. (President, Marketplaces) Sell 1,436 shares, Cann Cynthia Cammett (Chief Accounting Officer) Sell 1,077 shares. Source: SEC Form 4.
| Date | Insider | Title | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-10 | Cann Cynthia Cammett | Chief Accounting Officer | Sell | 4,788 | $147,375 |
| 2026-08-10 | Hill John W | Director | Sell | 3,500 | $105,735 |
| 2026-08-05 | FLORANCE ANDREW C | Founder and CEO | Buy | 83,300 | $2.5M |
| 2026-08-04 | SAINT FREDERICK G. | President, Marketplaces | Sell | 1,436 | $41,299 |
| 2026-08-04 | Cann Cynthia Cammett | Chief Accounting Officer | Sell | 1,077 | $30,975 |
| 2026-07-06 | LOWN CHRISTIAN M. | Chief Financial Officer | Sell | 5,597 | $164,328 |
| 2026-06-24 | Sams Louise S | Director | Buy | 8,262 | $0 |
| 2026-06-24 | Hill John W | Director | Buy | 8,262 | $0 |
| 2026-06-24 | Musslewhite Robert W | Director | Buy | 8,262 | $0 |
| 2026-06-24 | BERISFORD JOHN L | Director | Buy | 8,262 | $0 |
| 2026-06-24 | Glaser Rachel C | Director | Buy | 8,262 | $0 |
| 2026-06-24 | Brunner Angelique G. | Director | Buy | 8,262 | $0 |
| 2026-06-24 | McCarthy Christine M | Director | Buy | 8,262 | $0 |
| 2026-06-16 | Cann Cynthia Cammett | Chief Accounting Officer | Sell | 461 | $14,770 |
| 2026-05-04 | FLORANCE ANDREW C | President and CEO | Buy | 68,330 | $2.4M |
| 2026-05-04 | FLORANCE ANDREW C | President and CEO | Buy | 3,100 | $111,042 |
| 2026-03-17 | Cann Cynthia Cammett | Chief Accounting Officer | Sell | 1,194 | $52,094 |
| 2026-03-17 | Ruggles Lisa | Senior VP, Global Operations | Sell | 2,977 | $129,887 |
| 2026-03-17 | Boxer Gene | General Counsel and Secretary | Sell | 428 | $18,674 |
| 2026-03-17 | SIMURO FRANK | Chief Technology Officer | Sell | 11,107 | $484,598 |
| 2026-03-17 | Boxer Gene | General Counsel and Secretary | Sell | 482 | $21,030 |
| 2026-03-17 | DESMARAIS MICHAEL J | Chief Human Resources Officer | Sell | 2,873 | $125,349 |
| 2026-03-11 | FLORANCE ANDREW C | President and CEO | Buy | 124,162 | $0 |
| 2026-03-11 | Boxer Gene | General Counsel and Secretary | Buy | 21,920 | $0 |
| 2026-03-11 | LOWN CHRISTIAN M. | Chief Financial Officer | Buy | 12,268 | $0 |
Source: SEC Form 4 filings · as of 2026-08-10