What the executives and directors of CoStar Group actually did with their own shares, decoded from three years of SEC Form 4 filings.
The tape: three years of insider trades
Every marker sits at the exact price reported on the Form 4. The line is the monthly median of all prices insiders reported, so the chart needs no market feed; the gray strip is routine flow (vestings, tax withholding, gifts) that headlines love to miscount as selling.
Where the shares went, last 12 months
Every Form 4 movement decomposed: what flowed in (grants, vested equity, purchases) and what flowed out (tax withholding, plan sales, discretionary sales, gifts). Counted in shares, because grants carry no price.
Skin in the game
Directly held shares as reported after each trade, indexed to 100 five years back. Direct holdings only: trust and family-entity positions are per-entity in the filings and do not sum honestly, so this chart refuses to guess. The steps are the trades.
Who holds what
| Insider | Role | Shares held | Buys 12 m | Sales 12 m |
|---|---|---|---|---|
| KLEIN MICHAEL R | Director | 1.8M | — | — |
| FLORANCE ANDREW C Founder and CEO | CEO | 1.8M | $7.5M | — |
| SIMURO FRANK Chief Technology Officer | Officer | 414.5K | — | — |
| Wheeler Scott T Chief Financial Officer | CFO | 348.2K | — | — |
| SAINT FREDERICK G. President, Marketplaces | Officer | 278.4K | $907K | $2.3M |
| NASSETTA CHRISTOPHER J | Director | 275.7K | — | — |
| Ruggles Lisa Senior VP, Global Operations | Officer | 174.9K | — | — |
| LOWN CHRISTIAN M. Chief Financial Officer | CFO | 129.7K | — | — |
| Glosserman Michael J | Director | 101.5K | — | — |
| Boxer Gene General Counsel and Secretary | Officer | 95.5K | — | — |
| DESMARAIS MICHAEL J Chief Human Resources Officer | Officer | 87.7K | — | — |
| Sams Louise S | Director | 28.7K | $48K | — |
| Musslewhite Robert W | Director | 26.5K | — | — |
| Hill John W | Director | 26.5K | — | $155K |
Open-market trade log
| Date | Insider | Type | Shares | Price | Value |
|---|---|---|---|---|---|
| 2026-08-04 | FLORANCE ANDREW C (CEO) | Open-market buy | 83.3K | $29.89 | $2.5M |
| 2026-05-01 | FLORANCE ANDREW C (CEO) | Open-market buy | 3,100 | $35.82 | $111K |
| 2026-05-01 | FLORANCE ANDREW C (CEO) | Open-market buy | 68.3K | $35.17 | $2.4M |
| 2026-03-06 | Sams Louise S (Director) | Open-market buy | 1,000 | $48.36 | $48K |
| 2026-03-02 | Glaser Rachel C (Director) | Open-market buy | 1,000 | $44.94 | $45K |
| 2026-03-02 | SAINT FREDERICK G. (Officer) | Open-market buy | 20K | $45.33 | $907K |
| 2026-02-27 | FLORANCE ANDREW C (CEO) | Open-market buy | 55.7K | $44.52 | $2.5M |
| 2025-11-13 | Hill John W (Director) | Discretionary sale | 2,250 | $68.68 | $155K |
| 2025-11-13 | Cann Cynthia Cammett (Officer) | Discretionary sale | 1,841 | $68.79 | $127K |
| 2025-08-28 | SAINT FREDERICK G. (Officer) | Discretionary sale | 25K | $90.33 | $2.3M |
| 2025-07-28 | Cann Cynthia Cammett (Officer) | Discretionary sale | 2,033 | $92.85 | $189K |
| 2025-07-28 | SAINT FREDERICK G. (Officer) | Discretionary sale | 25K | $93.23 | $2.3M |
| 2025-06-11 | SAINT FREDERICK G. (Officer) | Discretionary sale | 25K | $81.10 | $2M |
| 2025-03-10 | Cann Cynthia Cammett (Officer) | Discretionary sale | 1,749 | $79.90 | $140K |
| 2024-12-10 | Hill John W (Director) | Discretionary sale | 2,735 | $76.76 | $210K |
| 2024-11-27 | NASSETTA CHRISTOPHER J (Director) | Discretionary sale | 1,681 | $80.39 | $135K |
| 2024-11-26 | DESMARAIS MICHAEL J (Officer) | Discretionary sale | 5,500 | $79.88 | $439K |
| 2024-11-11 | Cann Cynthia Cammett (Officer) | Discretionary sale | 1,310 | $76.85 | $101K |
| 2024-10-25 | FLORANCE ANDREW C (CEO) | Open-market buy | 14.7K | $74.67 | $1.1M |
| 2024-10-25 | KLEIN MICHAEL R (Director) | Discretionary sale | 71.6K | $74.69 | $5.4M |
| 2024-07-31 | Cann Cynthia Cammett (Officer) | Discretionary sale | 1,200 | $78.20 | $94K |
| 2024-07-30 | Hill John W (Director) | Discretionary sale | 1,325 | $78.16 | $104K |
| 2024-05-16 | SAINT FREDERICK G. (Officer) | Discretionary sale | 2,500 | $88.43 | $221K |
| 2024-05-09 | Ruggles Lisa (Officer) | Discretionary sale | 20K | $91.15 | $1.8M |
| 2024-04-26 | Wheeler Scott T (CFO) | Discretionary sale | 122.7K | $92.61 | $11.4M |
| 2024-04-26 | DESMARAIS MICHAEL J (Officer) | Discretionary sale | 3,800 | $92.67 | $352K |
| 2023-11-28 | Hill John W (Director) | Discretionary sale | 3,020 | $84.07 | $254K |
| 2023-11-08 | NASSETTA CHRISTOPHER J (Director) | Discretionary sale | 1,500 | $77.86 | $117K |
| 2023-06-30 | Ruggles Lisa (Officer) | Discretionary sale | 30.5K | $91.42 | $2.8M |
| 2023-06-28 | Wheeler Scott T (CFO) | Discretionary sale | 21.5K | $89.30 | $1.9M |
| 2023-06-27 | SIMURO FRANK (Officer) | Discretionary sale | 92.3K | $89.65 | $8.3M |
| 2023-06-26 | Hill John W (Director) | Discretionary sale | 1,500 | $86.57 | $130K |
| 2023-06-12 | Wheeler Scott T (CFO) | Discretionary sale | 24.7K | $80.68 | $2M |
| 2023-06-07 | SAINT FREDERICK G. (Officer) | Discretionary sale | 30K | $80.24 | $2.4M |
| 2023-04-28 | FLORANCE ANDREW C (CEO) | Discretionary sale | 360.5K | $76.77 | $27.7M |
| 2023-03-31 | Hill John W (Director) | Discretionary sale | 2,300 | $68.50 | $158K |
| 2023-03-08 | DESMARAIS MICHAEL J (Officer) | Discretionary sale | 5,600 | $70.36 | $394K |
| 2023-03-01 | SIMURO FRANK (Officer) | Discretionary sale | 35.2K | $70.09 | $2.5M |
| 2022-11-03 | Hill John W (Director) | Discretionary sale | 3,650 | $78.92 | $288K |
| 2022-10-28 | DESMARAIS MICHAEL J (Officer) | Discretionary sale | 1,296 | $82.81 | $107K |
| 2022-08-10 | Hill John W (Director) | Discretionary sale | 1,400 | $74.49 | $104K |
| 2022-08-05 | KLEIN MICHAEL R (Director) | Discretionary sale | 150K | $72.42 | $10.9M |
| 2022-08-03 | DESMARAIS MICHAEL J (Officer) | Discretionary sale | 2,000 | $72.51 | $145K |
| 2022-05-24 | Hill John W (Director) | Discretionary sale | 1,750 | $57.07 | $100K |
| 2022-05-02 | DESMARAIS MICHAEL J (Officer) | Discretionary sale | 1,000 | $63.14 | $63K |
| 2022-03-02 | Ruggles Lisa (Officer) | Discretionary sale | 21.6K | $59.88 | $1.3M |
| 2021-11-11 | Wheeler Scott T (CFO) | Discretionary sale | 85 | $81.72 | $7K |
| 2021-11-10 | NASSETTA CHRISTOPHER J (Director) | Discretionary sale | 2,120 | $83.21 | $176K |
| 2021-11-05 | Kaplan Laura Cox (Director) | Discretionary sale | 4,040 | $83.29 | $336K |
| 2021-10-29 | Hill John W (Director) | Discretionary sale | 9,235 | $86.97 | $803K |
| 2021-08-09 | Hill John W (Director) | Discretionary sale | 6,160 | $85.77 | $528K |
| 2021-04-30 | Kaplan Laura Cox (Director) | Discretionary sale | 1,062 | $869.03 | $923K |
| 2021-03-23 | SAINT FREDERICK G. (Officer) | Discretionary sale | 7,834 | $831.70 | $6.5M |
| 2021-03-16 | Wheeler Scott T (CFO) | Discretionary sale | 7,326 | $843.28 | $6.2M |
| 2021-03-10 | FLORANCE ANDREW C (CEO) | Discretionary sale | 19.6K | $818.37 | $16M |
| 2020-09-02 | Ruggles Lisa (Officer) | Discretionary sale | 7,596 | $870.00 | $6.6M |
| 2020-08-27 | FLORANCE ANDREW C (CEO) | Discretionary sale | 15.6K | $851.66 | $13.3M |
| 2020-08-26 | FLORANCE ANDREW C (CEO) | Discretionary sale | 15.6K | $848.16 | $13.2M |
| 2020-08-12 | Linnington Matthew (Officer) | Discretionary sale | 2,419 | $826.32 | $2M |
| 2020-08-04 | Wheeler Scott T (CFO) | Discretionary sale | 12K | $826.71 | $9.9M |
“Since trade” compares with the latest insider-implied price, not a market quote; this site carries no market data by design.
Filing hygiene
How to read this
A Form 4 transaction code decides everything. P is an open-market purchase and S an open-market sale; those two are the only codes where an insider chose to trade. A is a grant, M an option exercise or vesting, F shares withheld to cover tax, G a gift. Most “insiders dumped billions” headlines are code F and M mechanics.
Sales flagged 10b5-1 run on a plan the insider adopted in advance; since 2023 every Form 4 carries that flag. Buys have historically predicted returns, sales mostly have not, and this page states filings, not advice.