COSTAR GROUP, INC. — Insider Transactions
Form 4 filings by directors, officers, and 10%+ shareholders
SEC rules require corporate insiders — including directors, executive officers, and any shareholder owning more than 10% of a company's shares — to report changes in their ownership within two business days of a transaction. These disclosures are filed as Form 4. Open-market purchases (code P) are generally considered the most meaningful signal, as insiders are spending their own money.
| Insider | Title | Type | Shares | Price | Value | Owns After | Date |
|---|---|---|---|---|---|---|---|
| Hill John W | — | Sale | 2,250 | $68.68 | $154,530 | 18,231 | Nov 13, 2025 |
| Cann Cynthia Cammett | Chief Accounting Officer | Sale | 1,841 | $68.79 | $126,642 | 23,211 | Nov 13, 2025 |
| McCarthy Christine M | — | Award / Grant | 2,973 | — | — | 2,973 | Sep 9, 2025 |
| Sams Louise S | — | Award / Grant | 3,291 | — | — | 19,409 | Sep 9, 2025 |
| BERISFORD JOHN L | — | Award / Grant | 2,973 | — | — | 2,973 | Sep 9, 2025 |
| Hill John W | — | Award / Grant | 3,177 | — | — | 20,481 | Sep 9, 2025 |
| Musslewhite Robert W | — | Award / Grant | 3,121 | — | — | 18,277 | Sep 9, 2025 |
| Glaser Rachel C | — | Award / Grant | 3,143 | — | — | 3,143 | Sep 9, 2025 |
| Brunner Angelique G. | — | Award / Grant | 3,143 | — | — | 10,166 | Sep 9, 2025 |
| SAINT FREDERICK G. | President, Marketplaces | Sale | 25,000 | $90.33 | $2,258,250 | 293,103 | Aug 28, 2025 |
| Cann Cynthia Cammett | Chief Accounting Officer | Tax Withholding | 719 | $95.19 | $68,442 | 25,052 | Aug 1, 2025 |
| SAINT FREDERICK G. | President, Marketplaces | Tax Withholding | 1,436 | $95.19 | $136,693 | 318,103 | Aug 1, 2025 |
| SAINT FREDERICK G. | President, Marketplaces | Sale | 25,000 | $93.23 | $2,330,750 | 319,539 | Jul 28, 2025 |
| Cann Cynthia Cammett | Chief Accounting Officer | Sale | 2,033 | $92.85 | $188,764 | 25,771 | Jul 28, 2025 |
| LOWN CHRISTIAN M. | Chief Financial Officer | Tax Withholding | 4,666 | $80.40 | $375,146 | 130,157 | Jul 1, 2025 |
| Cann Cynthia Cammett | Chief Accounting Officer | Tax Withholding | 461 | $81.16 | $37,415 | 27,804 | Jun 15, 2025 |
| SAINT FREDERICK G. | President, Marketplaces | Sale | 25,000 | $81.10 | $2,027,500 | 344,539 | Jun 11, 2025 |
| Ruggles Lisa | Senior VP, Global Operations | Tax Withholding | 12 | $73.56 | $883 | 211,201 | Jun 1, 2025 |
| Ruggles Lisa | Senior VP, Global Operations | Tax Withholding | 1,958 | $78.73 | $154,153 | 211,213 | Mar 15, 2025 |
| Cann Cynthia Cammett | Chief Accounting Officer | Tax Withholding | 1,191 | $78.73 | $93,767 | 28,265 | Mar 15, 2025 |
| Boxer Gene | General Counsel and Secretary | Tax Withholding | 481 | $78.73 | $37,869 | 78,572 | Mar 15, 2025 |
| DESMARAIS MICHAEL J | Chief Human Resources Officer | Tax Withholding | 3,641 | $78.73 | $286,656 | 79,118 | Mar 15, 2025 |
| SIMURO FRANK | Chief Technology Officer | Tax Withholding | 5,700 | $78.73 | $448,761 | 483,599 | Mar 15, 2025 |
| Cann Cynthia Cammett | Chief Accounting Officer | Award / Grant | 1,498 | — | — | 33,715 | Mar 5, 2025 |
| Boxer Gene | General Counsel and Secretary | Award / Grant | 12,492 | — | — | 79,053 | Mar 5, 2025 |
| FLORANCE ANDREW C | President and CEO | Award / Grant | 76,232 | — | — | 1,672,832 | Mar 5, 2025 |
| DESMARAIS MICHAEL J | Chief Human Resources Officer | Award / Grant | 9,026 | — | — | 82,759 | Mar 5, 2025 |
| Ruggles Lisa | Senior VP, Global Operations | Tax Withholding | 7,410 | $76.25 | $565,013 | 213,171 | Mar 1, 2025 |
| SAINT FREDERICK G. | President, Marketplaces | Tax Withholding | 8,252 | $76.25 | $629,215 | 369,539 | Mar 1, 2025 |
| Boxer Gene | General Counsel and Secretary | Award / Grant | 26,897 | — | — | 70,205 | Mar 1, 2025 |
| FLORANCE ANDREW C | President and CEO | Tax Withholding | 41,296 | $76.25 | $3,148,820 | 1,596,600 | Mar 1, 2025 |
| SIMURO FRANK | Chief Technology Officer | Tax Withholding | 12,432 | $76.25 | $947,940 | 489,299 | Mar 1, 2025 |
| DESMARAIS MICHAEL J | Chief Human Resources Officer | Tax Withholding | 3,893 | $76.25 | $296,841 | 73,733 | Feb 27, 2025 |
| Cann Cynthia Cammett | Chief Accounting Officer | Tax Withholding | 813 | $76.25 | $61,991 | 32,217 | Feb 27, 2025 |
| LOWN CHRISTIAN M. | Chief Financial Officer | Award / Grant | 97,600 | — | — | 134,823 | Feb 20, 2025 |
| FLORANCE ANDREW C | President and CEO | Disposition | 28,896 | — | — | 1,219,967 | Feb 20, 2025 |
| SIMURO FRANK | Chief Technology Officer | Disposition | 6,452 | — | — | 378,567 | Feb 20, 2025 |
| SAINT FREDERICK G. | President, Marketplaces | Tax Withholding | 6,602 | $73.27 | $483,729 | 280,191 | Feb 20, 2025 |
| SIMURO FRANK | Chief Technology Officer | Tax Withholding | 5,485 | $74.06 | $406,219 | 385,019 | Feb 15, 2025 |
| Ruggles Lisa | Senior VP, Global Operations | Tax Withholding | 3,531 | $74.06 | $261,506 | 169,074 | Feb 15, 2025 |
| FLORANCE ANDREW C | President and CEO | Tax Withholding | 14,235 | $74.06 | $1,054,244 | 1,248,863 | Feb 15, 2025 |
| SAINT FREDERICK G. | President, Marketplaces | Tax Withholding | 2,349 | $74.06 | $173,967 | 293,245 | Feb 15, 2025 |
| Ruggles Lisa | Senior VP, Global Operations | Award / Grant | 65,440 | — | — | 220,581 | Feb 13, 2025 |
| Hill John W | — | Gift | 195 | — | — | 17,304 | Dec 10, 2024 |
| KLEIN MICHAEL R | — | Gift | 64,909 | — | — | 1,848,592 | Dec 10, 2024 |
| NASSETTA CHRISTOPHER J | — | Sale | 1,681 | $80.39 | $135,136 | 229,715 | Nov 27, 2024 |
| DESMARAIS MICHAEL J | Chief Human Resources Officer | Sale | 5,500 | $79.88 | $439,340 | 58,798 | Nov 26, 2024 |
| KLEIN MICHAEL R | — | Sale | 71,633 | $74.69 | $5,350,269 | 1,913,501 | Oct 25, 2024 |
| FLORANCE ANDREW C | President and CEO | Purchase | 14,731 | $74.67 | $1,099,966 | 1,263,098 | Oct 25, 2024 |
| Cann Cynthia Cammett | Chief Accounting Officer | Sale | 1,749 | $79.90 | $139,745 | 29,456 | Jul 31, 2024 |