CSGP (CoStar Group Inc)
Insider Trading Activity
Every open-market purchase and sale reported by CSGP officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-10 | Cynthia Cammett Cann | Chief Accounting Officer | Sell | — | — |
| 2026-08-10 | John W Hill | Director | Sell | — | — |
| 2026-08-05 | ANDREW C FLORANCE | Founder and CEO | Buy | — | — |
| 2026-08-04 | Robin Jack Rossmann | Chief Financial Officer | A | — | — |
| 2026-08-04 | G. SAINT FREDERICK | President, Marketplaces | F | — | — |
| 2026-08-04 | Cynthia Cammett Cann | Chief Accounting Officer | F | — | — |
| 2026-07-06 | CHRISTIAN M. LOWN | Chief Financial Officer | F | — | — |
| 2026-06-24 | Christine M McCarthy | Director | A | — | — |
| 2026-06-24 | Louise S Sams | Director | A | — | — |
| 2026-06-24 | Robert W Musslewhite | Director | A | — | — |
| 2026-06-24 | JOHN L BERISFORD | Director | A | — | — |
| 2026-06-24 | Angelique G. Brunner | Director | A | — | — |
| 2026-06-24 | John W Hill | Director | A | — | — |
| 2026-06-24 | Rachel C Glaser | Director | A | — | — |
| 2026-06-16 | Cynthia Cammett Cann | Chief Accounting Officer | F | — | — |
| 2026-05-04 | ANDREW C FLORANCE | President and CEO | Buy | — | — |
| 2026-03-17 | Gene Boxer | General Counsel and Secretary | F | — | — |
| 2026-03-17 | Cynthia Cammett Cann | Chief Accounting Officer | F | — | — |
| 2026-03-17 | MICHAEL J DESMARAIS | Chief Human Resources Officer | F | — | — |
| 2026-03-17 | FRANK SIMURO | Chief Technology Officer | F | — | — |
| 2026-03-17 | Gene Boxer | General Counsel and Secretary | F | — | — |
| 2026-03-17 | Lisa Ruggles | Senior VP, Global Operations | F | — | — |
| 2026-03-11 | MICHAEL J DESMARAIS | Chief Human Resources Officer | A | — | — |
| 2026-03-11 | Gene Boxer | General Counsel and Secretary | A | — | — |
| 2026-03-11 | CHRISTIAN M. LOWN | Chief Financial Officer | A | — | — |
| 2026-03-11 | ANDREW C FLORANCE | President and CEO | A | — | — |
| 2026-03-11 | Cynthia Cammett Cann | Chief Accounting Officer | A | — | — |
| 2026-03-09 | Louise S Sams | Director | Buy | — | — |
| 2026-03-03 | G. SAINT FREDERICK | President, Marketplaces | MIXED | — | — |
| 2026-03-03 | Rachel C Glaser | Director | Buy | — | — |
| 2026-03-03 | FRANK SIMURO | Chief Technology Officer | F | — | — |
| 2026-03-03 | Lisa Ruggles | Senior VP, Global Operations | F | — | — |
| 2026-03-03 | Cynthia Cammett Cann | Chief Accounting Officer | F | — | — |
| 2026-03-03 | MICHAEL J DESMARAIS | Chief Human Resources Officer | F | — | — |
| 2026-03-03 | Gene Boxer | General Counsel and Secretary | F | — | — |
| 2026-03-03 | ANDREW C FLORANCE | President and CEO | F | — | — |
| 2026-03-03 | G. SAINT FREDERICK | President, Marketplaces | A | — | — |
| 2026-03-03 | CHRISTIAN M. LOWN | Chief Financial Officer | F | — | — |
| 2026-03-02 | ANDREW C FLORANCE | President and CEO | Buy | — | — |
| 2026-02-23 | Lisa Ruggles | Senior VP, Global Operations | MIXED | — | — |
| 2026-02-23 | ANDREW C FLORANCE | President and CEO | MIXED | — | — |
| 2026-02-23 | G. SAINT FREDERICK | President, Marketplaces | MIXED | — | — |
| 2026-02-23 | FRANK SIMURO | Chief Technology Officer | MIXED | — | — |
| 2026-02-18 | G. SAINT FREDERICK | President, Marketplaces | F | — | — |
| 2026-02-18 | Lisa Ruggles | Senior VP, Global Operations | F | — | — |
| 2026-02-18 | ANDREW C FLORANCE | President and CEO | F | — | — |
| 2026-02-18 | FRANK SIMURO | Chief Technology Officer | F | — | — |
| 2025-11-17 | Cynthia Cammett Cann | Chief Accounting Officer | Sell | — | — |
| 2025-11-17 | John W Hill | Director | Sell | — | — |
| 2025-09-11 | Angelique G. Brunner | Director | A | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | Director | 2,942,770 | — |
| — | Director | 1,848,592 | — |
| — | Founder and CEO | 1,806,165 | — |
| — | Director | 1,270,490 | — |
| — | Chief Financial Officer | 414,730 | — |
| — | Chief Technology Officer | 414,491 | — |
| — | Chief Financial Officer | 304,958 | — |
| — | Managing Director, CoStar UK | 286,320 | — |
| — | President, Marketplaces | 278,415 | — |
| — | Director | 275,715 | — |
| — | Sr. Vice President, Research | 222,200 | — |
| — | Director | 217,050 | — |
| — | Executive VP, Sales | 197,660 | — |
| — | Senior VP, Global Operations | 174,915 | — |
| — | Sr. VP-Sales, Customer Service | 153,340 | — |
| — | Chief Financial Officer | 129,653 | — |
| — | Sr. VP-Sales, Customer Service | 106,820 | — |
| — | Director | 101,465 | — |
| — | General Counsel and Secretary | 95,517 | — |
| — | Chief Human Resources Officer | 87,725 | — |
| — | Executive VP, Corp. Dev. | 65,400 | — |
| — | Director | 64,560 | — |
| — | Vice President, Research | 63,070 | — |
| — | Director | 57,360 | — |
| — | Director | 28,671 | — |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the CSGP quote page; the site-wide leaderboard is on the insider transactions hub.