As of the latest Form 4 filed Jul 6, 2026.
What CoStar Group Inc insiders — officers, directors and 10% owners — have bought and sold in their own stock, straight from their SEC Form 4 filings. Values are shares × the reported transaction price where both are disclosed.
Buys plotted up, sells down; bar height is the disclosed dollar value (shares × reported price). Our Form 4 history is only complete from mid-2026, so early months are sparse — the series fills in as more filings land. Open-market purchases and sales only.
Newest filing first — the 35 most recent filings for CSGP.
| Filed | Trade date | Insider | Transaction | Shares | Price | Value | 10b5-1 | Filing |
|---|---|---|---|---|---|---|---|---|
| 2026-07-06 | 2026-07-01 | LOWN CHRISTIAN M. Chief Financial Officer | FTax | −5.60K | $29.36 | $164K | No | Form 4 ↗ |
| 2026-06-24 | 2026-06-23 | Sams Louise S Director | AAward | +8.26K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-24 | 2026-06-23 | Brunner Angelique G. Director | AAward | +8.26K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-24 | 2026-06-23 | McCarthy Christine M Director | AAward | +8.26K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-24 | 2026-06-23 | Glaser Rachel C Director | AAward | +8.26K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-24 | 2026-06-23 | BERISFORD JOHN L Director | AAward | +8.26K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-24 | 2026-06-23 | Musslewhite Robert W Director | AAward | +8.26K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-24 | 2026-06-23 | Hill John W Director | AAward | +8.26K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-16 | 2026-06-15 | Cann Cynthia Cammett Chief Accounting Officer | FTax | −461.00 | $32.04 | $14.8K | No | Form 4 ↗ |
| 2026-05-04 | 2026-05-01 | FLORANCE ANDREW C President and CEO | PPurchase | +3.10K | $35.82 | $111K | No | Form 4 ↗ |
| 2026-05-04 | 2026-05-01 | FLORANCE ANDREW C, President and CEO | PPurchase | +68.3K | $35.17 | $2.40M | No | Form 4 ↗ |
| 2026-03-17 | 2026-03-15 | SIMURO FRANK Chief Technology Officer | FTax | −11.1K | $43.63 | $485K | No | Form 4 ↗ |
| 2026-03-17 | 2026-03-15 | DESMARAIS MICHAEL J Chief Human Resources Officer | FTax | −2.87K | $43.63 | $125K | No | Form 4 ↗ |
| 2026-03-17 | 2026-03-15 | Boxer Gene General Counsel and Secretary | FTax | −428.00 | $43.63 | $18.7K | No | Form 4 ↗ |
| 2026-03-17 | 2026-03-15 | Ruggles Lisa Senior VP, Global Operations | FTax | −2.98K | $43.63 | $130K | No | Form 4 ↗ |
| 2026-03-17 | 2026-03-15 | Cann Cynthia Cammett Chief Accounting Officer | FTax | −1.19K | $43.63 | $52.1K | No | Form 4 ↗ |
| 2026-03-11 | 2026-03-10 | DESMARAIS MICHAEL J Chief Human Resources Officer | AAward | +17.7K | — | — | No | Form 4 ↗ |
| 2026-03-11 | 2026-03-10 | Boxer Gene General Counsel and Secretary | AAward | +21.9K | — | — | No | Form 4 ↗ |
| 2026-03-11 | 2026-03-10 | LOWN CHRISTIAN M. Chief Financial Officer | AAward | +12.3K | — | — | No | Form 4 ↗ |
| 2026-03-11 | 2026-03-10 | Cann Cynthia Cammett Chief Accounting Officer | AAward | +4.37K | — | — | No | Form 4 ↗ |
| 2026-03-11 | 2026-03-10 | FLORANCE ANDREW C President and CEO | AAward | +124K | — | — | No | Form 4 ↗ |
| 2026-03-09 | 2026-03-06 | Sams Louise S Director | PPurchase | +1.00K | $48.36 | $48.4K | No | Form 4 ↗ |
| 2026-03-02 | 2026-02-27 | FLORANCE ANDREW C President and CEO | PPurchase | +55.7K | $44.52 | $2.48M | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | SIMURO FRANK Chief Technology Officer | FTax | −4.42K | $49.07 | $217K | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | SIMURO FRANK, Chief Technology Officer | DDisposition | −30.7K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | Ruggles Lisa Senior VP, Global Operations | FTax | −3.22K | $49.07 | $158K | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | Ruggles Lisa, Senior VP, Global Operations | DDisposition | −17.6K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | SAINT FREDERICK G. President, Marketplaces | FTax | −2.15K | $49.07 | $105K | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | SAINT FREDERICK G., President, Marketplaces | DDisposition | −17.6K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | FLORANCE ANDREW C President and CEO | FTax | −19.2K | $49.07 | $943K | No | Form 4 ↗ |
| 2026-02-23 | 2026-02-19 | FLORANCE ANDREW C, President and CEO | DDisposition | −105K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-02-18 | 2026-02-15 | SIMURO FRANK Chief Technology Officer | FTax | −4.15K | $44.99 | $187K | No | Form 4 ↗ |
| 2026-02-18 | 2026-02-15 | Ruggles Lisa Senior VP, Global Operations | FTax | −3.58K | $44.99 | $161K | No | Form 4 ↗ |
| 2026-02-18 | 2026-02-15 | SAINT FREDERICK G. President, Marketplaces | FTax | −2.42K | $44.99 | $109K | No | Form 4 ↗ |
| 2026-02-18 | 2026-02-15 | FLORANCE ANDREW C President and CEO | FTax | −17.5K | $44.99 | $787K | No | Form 4 ↗ |
Insiders — a company’s officers, directors and holders of more than 10% of its stock — must report any trade in that stock to the SEC on a Form 4 within two business days. Each row here is one transaction from those filings.
The transaction code tells you what happened: Purchase (P) and Sale (S) are open-market trades — the ones markets watch most; Award (A) is a granted stock or unit, Option exercise (M) converts options into shares, and Gift (G) is a transfer for no consideration. Awards, exercises and gifts are largely compensation or administrative, not a directional bet.
One caveat on sales: many are made under a Rule 10b5-1 plan scheduled months in advance, so a sale is not automatically a bearish signal. Insider activity is a noisy input — read it alongside the filings, not on its own.
See also CSGP’s full analysis or the market-wide insider trading feed. The tabs above jump to CSGP’s other SEC data.
Source: SEC Form 4 filings for CSGP, parsed from EDGAR. Transaction prices are as reported in the filing — SEC public-domain data, not market quotes. Values are shares × reported price where both are disclosed; grants and gifts often carry no price. A delayed record of what insiders reported, not a live position or a recommendation.
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