CoStar Group, Inc. (CSGP) Ownership
CSGP ownership summary
as of October 17, 2026- Institutions
- 104.7% of shares outstanding
- Insiders
- 0.76% of shares outstanding
- Shares outstanding
- 405.2M
- Float
- 401.8M shares available to trade
- Short interest
- 3.30% 13.3M shares short
- Days to cover
- 1.78 short interest down 10.5% vs prior month
- Institutions 104.65%
- Insiders 0.76%
CSGP top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard Portfolio Management, LLC | 9.36% | 37.9M | $1.23B | −319,289 (−0.8%) | June 30, 2026 |
| 2 | BlackRock Inc | 8.35% | 33.8M | $1.09B | +5,785 (+0.0%) | June 30, 2026 |
| 3 | Vanguard Capital Management, LLC | 6.59% | 26.7M | $862.2M | −740,111 (−2.7%) | June 30, 2026 |
| 4 | BAMCO Inc | 5.34% | 21.6M | $698.8M | +5.3M (+32.6%) | June 30, 2026 |
| 5 | State Street Corp | 4.54% | 18.4M | $594.9M | −240,099 (−1.3%) | June 30, 2026 |
| 6 | Capital Research & Mgmt Co - Division 3 | 4.11% | 16.6M | $537.7M | +1.1M (+7.3%) | June 30, 2026 |
| 7 | Baillie Gifford & Co Limited. | 3.25% | 13.2M | $425.0M | −456,757 (−3.4%) | June 30, 2026 |
| 8 | Geode Capital Management, LLC | 3.00% | 12.2M | $393.1M | −282,183 (−2.3%) | June 30, 2026 |
| 9 | Akre Capital Management, LLC | 2.89% | 11.7M | $378.0M | +1.4M (+13.1%) | June 30, 2026 |
| 10 | Polen Capital | 2.16% | 8.8M | $283.0M | −3.8M (−30.3%) | June 30, 2026 |
| 11 | AQR Capital Management LLC | 2.08% | 8.4M | $272.9M | +7.2M (+568.8%) | June 30, 2026 |
| 12 | Jupiter Topco LLC | 1.93% | 7.8M | $253.1M | +7.8M (0.0%) | June 30, 2026 |
| 13 | HHG PLC | 1.91% | 7.7M | $249.6M | +250,772 (+3.4%) | March 31, 2026 |
| 14 | Amvescap Plc. | 1.68% | 6.8M | $220.0M | −9.1M (−57.3%) | June 30, 2026 |
| 15 | EdgePoint Investment | 1.47% | 6.0M | $192.2M | +6.0M (0.0%) | June 30, 2026 |
| 16 | NORGES BANK | 1.47% | 5.9M | $192.2M | −1.1M (−16.1%) | June 30, 2026 |
| 17 | Morgan Stanley - Brokerage Accounts | 1.35% | 5.5M | $177.2M | +73,255 (+1.4%) | June 30, 2026 |
| 18 | Meritage Group LP | 1.33% | 5.4M | $174.3M | +2.1M (+62.0%) | June 30, 2026 |
| 19 | The Goldman Sachs Group Inc | 1.27% | 5.1M | $165.7M | −4.1M (−44.5%) | June 30, 2026 |
| 20 | JPMorgan Chase & Co | 1.22% | 4.9M | $159.6M | +3.1M (+167.1%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 11 holders added 34.2M shares and 9 cut 20.2M.
CSGP top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard Real Estate Index Investor | 3.77% | 15.3M | $493.6M | −618,570 (−3.9%) | August 31, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 3.21% | 13.0M | $419.7M | −14,222 (−0.1%) | August 31, 2026 |
| 3 | Vanguard 500 Index Investor | 2.68% | 10.8M | $350.4M | +131,999 (+1.2%) | August 31, 2026 |
| 4 | Baron Partners Retail | 2.47% | 10.0M | $323.9M | −5.5M (−35.3%) | September 30, 2026 |
| 5 | Akre Focus ETF | 2.10% | 8.5M | $274.4M | — | September 30, 2026 |
| 6 | Invesco S&P 500® Equal Weight ETF | 1.63% | 6.6M | $213.7M | −13,680 (−0.2%) | September 30, 2026 |
| 7 | Vanguard US Growth Investor | 1.37% | 5.5M | $179.0M | — | June 30, 2026 |
| 8 | Janus Henderson Enterprise D | 1.37% | 5.5M | $178.7M | — | August 31, 2026 |
| 9 | American Funds Fundamental Invs A | 1.35% | 5.5M | $176.7M | −8,089 (−0.1%) | June 30, 2026 |
| 10 | iShares Core S&P 500 ETF | 1.33% | 5.4M | $174.5M | −8,695 (−0.2%) | September 30, 2026 |
| 11 | Fidelity 500 Index | 1.31% | 5.3M | $171.3M | +20,345 (+0.4%) | August 31, 2026 |
| 12 | State Street® SPDR® S&P 500® ETF | 1.24% | 5.0M | $162.3M | — | September 30, 2026 |
| 13 | American Funds Growth Fd of Amer A | 1.19% | 4.8M | $155.8M | — | June 30, 2026 |
| 14 | Vanguard Small Cap Index | 1.16% | 4.7M | $151.8M | +4,047 (+0.1%) | August 31, 2026 |
| 15 | Vanguard MStar Mid Cap Index Instl | 1.09% | 4.4M | $142.7M | −1,334 (−0.0%) | August 31, 2026 |
| 16 | Vanguard MStar Growth Index Investor | 1.05% | 4.3M | $138.1M | −6,557 (−0.2%) | August 31, 2026 |
| 17 | American Funds AMCAP A | 0.96% | 3.9M | $126.1M | −215,756 (−5.2%) | June 30, 2026 |
| 18 | State Street Real Estate Sel SectSPDRETF | 0.90% | 3.7M | $118.0M | +20,792 (+0.6%) | September 30, 2026 |
| 19 | American Funds IS® Growth 1 | 0.71% | 2.9M | $92.3M | — | June 30, 2026 |
| 20 | Vanguard Real Estate II Index | 0.67% | 2.7M | $87.8M | −84,922 (−3.0%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
CSGP insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-03-30 | Ro Khanna | Sell | $40.88 | — | — |
| 2026-03-23 | Ro Khanna | Buy | $42.91 | — | — |
| 2026-03-13 | Gilbert Ray Cisneros, Jr. | Buy | $43.63 | — | — |
| 2026-03-10 | Ro Khanna | Buy | $46.33 | — | — |
| 2026-03-06 | Louise S Sams | Buy | $48.36 | 1,000 | $48,360 |
| 2026-02-24 | Ro Khanna | Buy | $49.15 | — | — |
| 2026-02-17 | Ro Khanna | Buy | $45.74 | — | — |
| 2026-02-05 | Ro Khanna | Sell | $50.99 | — | — |
| 2026-01-29 | Ro Khanna | Buy | $61.93 | — | — |
| 2026-01-28 | Gilbert Ray Cisneros, Jr. | Buy | $65.20 | — | — |
| 2026-01-13 | Ro Khanna | Sell | $61.82 | — | — |
| 2026-01-06 | Ro Khanna | Sell | $67.20 | — | — |
| 2025-12-10 | Gilbert Ray Cisneros, Jr. | Buy | $67.87 | — | — |
| 2025-11-10 | Ro Khanna | Sell | $67.23 | — | — |
| 2025-11-03 | Ro Khanna | Sell | $69.38 | — | — |
| 2025-10-15 | Gilbert Ray Cisneros, Jr. | Buy | $75.19 | — | — |
| 2025-09-30 | Gilbert Ray Cisneros, Jr. | Buy | $84.37 | — | — |
| 2025-09-25 | Lisa C. McClain | Sell | $83.09 | — | — |
| 2025-09-22 | Gilbert Ray Cisneros, Jr. | Buy | $86.31 | — | — |
| 2025-08-28 | Frederick G Saint | Sell | $90.33 | 25,000 | $2.3M |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
CSGP shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns CSGP
Institutional investors own 104.7% of CoStar's shares and insiders 0.76%. The largest holder is Vanguard Portfolio Management, LLC with 9.36% of the shares (37.9M), as of June 30, 2026. Among the top 20 institutions, 11 added shares and 9 reduced their stake in the latest filings. Short interest is 3.30% of the float, or 1.78 days of average trading volume. The share count rose 30.5% since 2014.
Related: CSGP analyst forecast, CSGP key metrics. See the CSGP stock overview for the latest quote and news.
CSGP ownership FAQ
Who owns the most CoStar stock?
The largest shareholders of CoStar are Vanguard Portfolio Management, LLC (9.36%), BlackRock Inc (8.35%), Vanguard Capital Management, LLC (6.59%), BAMCO Inc (5.34%), State Street Corp (4.54%).
What percentage of CoStar is owned by institutions?
Institutions hold 104.7% of CoStar's shares outstanding; insiders hold 0.76%.
Which funds own CoStar?
The largest fund holders of CoStar are Vanguard Real Estate Index Investor (3.77%), Vanguard MStar Total Stk Mkt Idx Invest (3.21%), Vanguard 500 Index Investor (2.68%), Baron Partners Retail (2.47%), Akre Focus ETF (2.10%).
What is CoStar's short interest?
13.3M shares of CoStar were sold short, 3.30% of the float; at the average daily volume it would take 1.78 days to cover.
Are insiders buying or selling CoStar?
Of the latest 20 reported insider transactions in CoStar (since August 28, 2025), 12 were purchases and 8 were sales.
How many shares of CoStar are outstanding?
CoStar has 405.2M shares outstanding, of which 401.8M are in the public float.