CoStar Group, Inc.
CoStar Group, Inc. (CSGP) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · CSGP · as of Mar 31, 2025
Ownership Breakdown
897
Institutional Holders
▲ 64 vs Q4
$33.95B
Total Inst. Value
▲ $5.08B vs Q4
408.36M
Shares Outstanding
freeFloat 98.64%
428.82M
13F Shares Held
▲ 25.55M vs Q4
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
CSGP largest shareholders · institutional ownership
Q1 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC services-business services, nec | 68.43M | 16.67% | 16.67% | $5.42T | May 9, 2025 | ▲ 2.71M |
BLACKROCK, INC. services-business services, nec | 37.46M | 9.12% | 9.12% | $2.97T | May 2, 2025 | ▼ 658.1K |
BAMCO INC /NY/ services-business services, nec | 19.03M | 4.64% | 4.64% | $1.51T | May 15, 2025 | ▼ 171.0K |
PRINCIPAL FINANCIAL GROUP INC services-business services, nec | 19.01M | 4.63% | 4.63% | $1.51T | Apr 28, 2025 | ▼ 178.4K |
STATE STREET CORP services-business services, nec | 17.57M | 4.28% | 4.28% | $1.39T | May 15, 2025 | ▲ 542.6K |
CAPITAL INTERNATIONAL INVESTORS services-business services, nec | 14.67M | 3.57% | 3.57% | $1.16T | May 12, 2025 | ▲ 637.5K |
GEODE CAPITAL MANAGEMENT, LLC services-business services, nec | 12.07M | 2.94% | 2.94% | $953.41B | May 13, 2025 | ▲ 591.7K |
AKRE CAPITAL MANAGEMENT LLC services-business services, nec | 9.31M | 2.27% | 2.27% | $737.92B | May 13, 2025 | ▼ 288 |
BAILLIE GIFFORD & CO services-business services, nec | 8.44M | 2.06% | 2.06% | $668.40B | May 7, 2025 | ▲ 524.6K |
MORGAN STANLEY services-business services, nec | 7.91M | 1.93% | 1.93% | $626.72B | May 15, 2025 | ▲ 3.57M |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q1 2025 vs prior quarter
Q1 2025
25
Increased
+19.98M shares3
New Positions
first time holders21
Decreased
−6.41M shares0
Sold Out
fully exitedNet shares change (top 50)
+13.57M
+19.98M / −6.41M
Net new holders
+7
3 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
CSGP insider trading · insider activity
Source: SEC Form 4
Insiders have been net buyers of shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
17
Buy transactions
26
Sell transactions
0.65
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
FLORANCE ANDREW C President and CEO | May 1, 2026 | Purchase | 3,100 | $35.82 | $111.0K | 1.72M | Form 4 ↗ |
FLORANCE ANDREW C President and CEO | May 1, 2026 | Purchase | 68,330 | $35.17 | $2.40M | 1.72M | Form 4 ↗ |
Boxer Gene General Counsel and Secretary | Mar 15, 2026 | Tax Withhold | 482 | $43.63 | $21.0K | 95.5K | Form 4 ↗ |
Ruggles Lisa Senior VP, Global Operations | Mar 15, 2026 | Tax Withhold | 2,977 | $43.63 | $129.9K | 174.9K | Form 4 ↗ |
Boxer Gene General Counsel and Secretary | Mar 15, 2026 | Tax Withhold | 428 | $43.63 | $18.7K | 95.5K | Form 4 ↗ |
SIMURO FRANK Chief Technology Officer | Mar 15, 2026 | Tax Withhold | 11,107 | $43.63 | $484.6K | 414.5K | Form 4 ↗ |
DESMARAIS MICHAEL J Chief Human Resources Officer | Mar 15, 2026 | Tax Withhold | 2,873 | $43.63 | $125.3K | 87.7K | Form 4 ↗ |
Cann Cynthia Cammett Chief Accounting Officer | Mar 15, 2026 | Tax Withhold | 1,194 | $43.63 | $52.1K | 25.1K | Form 4 ↗ |
Cann Cynthia Cammett Chief Accounting Officer | Mar 10, 2026 | Award | 4,374 | $46.34 | $202.7K | 26.3K | Form 4 ↗ |
FLORANCE ANDREW C President and CEO | Mar 10, 2026 | Award | 124,162 | $46.34 | $5.75M | 1.65M | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
CoStar Group, Inc. (CSGP) is primarily owned by institutional investors, who hold approximately 100.0% of total shares outstanding. Company insiders own approximately 1.36%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of CoStar Group, Inc. is VANGUARD GROUP INC, holding approximately 68.43 million shares — equal to 16.67% of outstanding shares — as of March 31, 2025.
A total of 897 institutional investors currently hold CSGP stock, with a combined institutional value of approximately $33.95 billion as of the most recent 13F filing period.
Frequently asked questions
CSGP ownershipCoStar Group, Inc. (CSGP) is primarily owned by institutional investors, who hold approximately 100.0% of shares. The largest shareholder is VANGUARD GROUP INC with a 16.67% stake. Company insiders hold 1.36%. Data sourced from SEC Form 13F as of March 31, 2025.