Costar Group
CSGP · NASDAQ
Who owns CSGP
Largest institutional holders, from their latest 13F filings
The 10 largest institutions hold 47.3% of CSGP’s shares.
- Vanguard Portfolio Management, LLC9.4%
- Vanguard Capital Management, LLC6.6%
- BlackRock Institutional Trust Company, N.A.6.1%
- Baron Capital Management, Inc.5.3%
- Next 6 largest institutions19.9%
- All other shareholders52.7%
| Holder | Shares | % of shares |
|---|---|---|
| Vanguard Portfolio Management, LLC | 37.91M | 9.36% |
| Vanguard Capital Management, LLC | 26.68M | 6.59% |
| BlackRock Institutional Trust Company, N.A. | 24.58M | 6.07% |
| Baron Capital Management, Inc. | 21.63M | 5.34% |
| State Street Investment Management (US) | 18.41M | 4.54% |
| Capital International Investors | 16.64M | 4.11% |
| Baillie Gifford & Co. | 13.15M | 3.25% |
| Geode Capital Management, L.L.C. | 12.17M | 3.00% |
| Akre Capital Management, LLC | 11.70M | 2.89% |
| Polen Capital Management, LLC | 8.76M | 2.16% |
Largest mutual fund holders
| Holder | Shares | % of shares |
|---|---|---|
| Vanguard Real Estate Index Fund | 15.90M | 3.92% |
| Baron Partners Fund | 15.49M | 3.82% |
| Vanguard Total Stock Market Index Fund | 13.01M | 3.21% |
| Vanguard 500 Index Fund | 10.71M | 2.64% |
| Akre Focus ETF | 8.49M | 2.10% |
Insider trades
Form 4 filings by officers, directors and large holders
Over the last 6 months, insiders bought $5.00M (3 trades) and sold $253.11K (2 trades) of CSGP on the open market.
| Insider | Type | Shares | Value |
|---|---|---|---|
| Rossmann Robin Jack | Tax withholding | 756 | $24.19K |
| Cann Cynthia Cammett | Sale | 4.79K | $147.37K |
| Hill John W | Sale | 3.50K | $105.73K |
| FLORANCE ANDREW C | Buy | 83.30K | $2.49M |
| SAINT FREDERICK G. | Tax withholding | 1.44K | $41.30K |
| Cann Cynthia Cammett | Tax withholding | 1.08K | $30.97K |
| Rossmann Robin Jack | Award | 34.77K | — |
| Cann Cynthia Cammett | Award | 26.08K | — |
| LOWN CHRISTIAN M. | Tax withholding | 5.60K | $164.33K |
| Sams Louise S | Award | 8.26K | — |
Congressional trades
Disclosed by members of Congress over the last 12 months
| Member | Type | Amount | Traded |
|---|---|---|---|
| Gilbert CisnerosHouse | Purchase | $1K–$15K | Aug 19, 2026 |
| Gil CisnerosHouse | Purchase | $1K–$15K | Mar 13, 2026 |
| Gil CisnerosHouse | Purchase | $1K–$15K | Jan 28, 2026 |
| Gil CisnerosHouse | Purchase | $1K–$15K | Dec 10, 2025 |
| Ro KhannaHouse | Sale | $1K–$15K | Nov 10, 2025 |
| Ro KhannaHouse | Sale | $1K–$15K | Nov 3, 2025 |
Short interest
Settled Sep 30, 2026
- Shares short
- 13.28M
- Days to cover
- 1.97
- % of shares outstanding
- 3.28%
- Average daily volume
- 6.73M
- Change since last report
- −10.5%
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