CoStar Group, Inc. (CSGP) shareholders
CSGPNasdaqServices-Business Services, NECFiscal year ends December 31
Financials through Q3 FY2026, quarter ended Sep 30, 2026Last filing: 10-Q on Oct 28, 2026Score 14/3011% below fair value
$30.10−0.16 (-0.55%)
Close on Nov 12, 2026Market cap $12.11BP/E 68.4Yield –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
100.0%
414M of 402M shares
Institutional holders
757
113 new, 142 sold out
Net institutional buying
6M
In Q2 2026
Insider trades, 12 months
7 buys · 4 sales
Net bought $7.95M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Vanguard Portfolio Management | 38,292,035 | 9.12% | 13G (passive) | Mar 31, 2026 |
| BlackRock, Inc. | 31,820,259 | 7.50% | 13G (passive) amendment | Mar 31, 2025 |
| Vanguard Capital Management | 31,613,997 | 7.53% | 13G (passive) | Mar 31, 2026 |
| Ronald Baron Joint filing with Baron Capital Group, Inc. (5.30%) | 21,626,763 | 5.30% | 13G (passive) | Jun 30, 2026 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of CSGP | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| Vanguard Portfolio Management LLC | 37,914,844 | 9.42% | $1.07B | −319,289 | 0.05% |
| BlackRock, Inc. | 33,813,969 | 8.40% | $957.61M | +5,785 | 0.01% |
| Vanguard Capital Management LLC | 26,683,792 | 6.63% | $755.68M | −740,111 | 0.02% |
| Bamco Inc /Ny/ | 21,626,763 | 5.38% | $612.47M | +5,312,588 | 0.92% |
| State Street Corp | 18,410,876 | 4.58% | $521.40M | −240,099 | 0.02% |
| Capital International Investors | 16,643,016 | 4.14% | $471.33M | +1,129,263 | 0.10% |
| Baillie Gifford & Co | 13,154,165 | 3.27% | $372.53M | −456,757 | 0.34% |
| Geode Capital Management, LLC | 12,166,469 | 3.02% | $343.30M | −282,183 | 0.02% |
| Akre Capital Management LLC | 11,699,396 | 2.91% | $331.33M | +1,351,123 | 6.47% |
| Polen Capital Management LLC | 8,759,314 | 2.18% | $248.06M | −3,811,054 | 2.14% |
| Aqr Capital Management LLC | 8,445,474 | 2.10% | $239.18M | +7,182,770 | 0.08% |
| Jupiter Topco LLC | 7,832,860 | 1.95% | $221.83M | New | 0.09% |
| Invesco Ltd. | 6,808,377 | 1.69% | $192.81M | −9,139,148 | 0.02% |
| EdgePoint Investment Group Inc. | 5,950,002 | 1.48% | $168.50M | New | 1.27% |
| Norges Bank | 5,949,912 | 1.48% | $168.50M | New | 0.02% |
| Morgan Stanley | 5,485,870 | 1.36% | $155.36M | +73,255 | 0.01% |
| Meritage Group LP | 5,394,164 | 1.34% | $152.76M | +2,065,158 | 5.89% |
| Goldman Sachs Group Inc | 5,129,484 | 1.27% | $145.27M | −4,116,328 | 0.01% |
| JPMorgan Chase & Co | 4,939,994 | 1.23% | $145.37M | +3,090,449 | 0.01% |
| Federated Hermes, Inc. | 4,426,727 | 1.10% | $125.36M | +3,128,769 | 0.18% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 757 | 414M | 100.0% | 113 / 303 | 264 / 142 | 78M | 73M |
| Q1 2026 | 797 | 416M | 100.0% | 130 / 307 | 277 / 166 | 135M | 72M |
| Q4 2025 | 847 | 426M | 100.0% | 103 / 274 | 387 / 143 | 60M | 47M |
| Q3 2025 | 905 | 416M | 100.0% | 108 / 365 | 313 / 63 | 25M | 35M |
| Q2 2025 | 873 | 426M | 100.0% | 101 / 355 | 316 / 75 | 24M | 28M |
| Q1 2025 | 857 | 430M | 100.0% | 140 / 377 | 264 / 75 | 46M | 25M |
| Q4 2024 | 805 | 410M | 100.0% | 144 / 295 | 278 / 96 | 51M | 39M |
| Q3 2024 | 772 | 400M | 99.4% | 91 / 308 | 284 / 78 | 66M | 24M |
| Q2 2024 | 766 | 397M | 98.6% | 99 / 277 | 284 / 92 | 20M | 38M |
| Q1 2024 | 766 | 416M | 100.0% | 91 / 300 | 266 / 55 | 35M | 15M |
| Q4 2023 | 736 | 398M | 98.8% | 105 / 282 | 262 / 50 | 23M | 18M |
| Q3 2023 | 689 | 392M | 97.5% | 65 / 276 | 252 / 85 | 14M | 21M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
628 funds held CSGP in Q2 2026, 45% of their shares through ETFs. Each fund counts once per quarter, from its quarter-end report.
| Fund | Shares | % of CSGP | Value | % of fund | As of |
|---|---|---|---|---|---|
| Vanguard Real Estate Index Fund | 15,894,241 | 3.95% | $457.12M | 0.63% | Jul 31, 2026 |
| Baron Partners Fund | 15,703,171 | 3.90% | $444.71M | 2.46% | Jun 30, 2026 |
| Vanguard Total Stock Market Index Fund | 12,965,607 | 3.22% | $367.19M | 0.02% | Jun 30, 2026 |
| Vanguard 500 Index Fund | 10,575,691 | 2.63% | $299.50M | 0.02% | Jun 30, 2026 |
| Akre Focus ETF | 8,491,693 | 2.11% | $244.22M | 4.65% | Jul 31, 2026 |
| iShares Core S&P 500 ETF | 5,616,586 | 1.40% | $159.06M | 0.02% | Jun 30, 2026 |
| Vanguard U.S. Growth Fund | 5,541,323 | 1.38% | $178.43M | 0.38% | May 31, 2026 |
| Janus Henderson Enterprise Fund | 5,532,268 | 1.38% | $156.67M | 0.70% | Jun 30, 2026 |
| American Funds Fundamental Investors | 5,469,000 | 1.36% | $154.88M | 0.09% | Jun 30, 2026 |
| Invesco S&P 500 Equal Weight ETF | 5,443,191 | 1.35% | $156.55M | 0.16% | Jul 31, 2026 |
| Fidelity 500 Index Fund | 5,423,688 | 1.35% | $174.64M | 0.02% | May 31, 2026 |
| Growth Fund of America | 4,823,033 | 1.20% | $155.30M | 0.04% | May 31, 2026 |
| Vanguard Small-Cap Index Fund | 4,683,646 | 1.16% | $132.64M | 0.07% | Jun 30, 2026 |
| Vanguard Mid-Cap Index Fund | 4,424,985 | 1.10% | $125.32M | 0.06% | Jun 30, 2026 |
| Vanguard Growth Index Fund | 4,310,388 | 1.07% | $122.07M | 0.03% | Jun 30, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Andrew C. Florance | Founder and CEO, Director | 1,806,165 | 0.45% | Aug 5, 2026 |
| Catrina Harding | Chief Human Resources Officer | – | – | Nov 10, 2026 |
| Robin Jack Rossmann | Chief Financial Officer | 85,935 | 0.02% | Oct 16, 2026 |
| Cynthia Cammett Cann | Chief Accounting Officer | 18,822 | 0.00% | Aug 10, 2026 |
| Frederick G. Saint | President, Marketplaces | 278,415 | 0.07% | Aug 4, 2026 |
| Christian M. Lown | Chief Financial Officer | 129,653 | 0.03% | Jul 6, 2026 |
| Gene Boxer | General Counsel and Secretary | 95,517 | 0.02% | Mar 17, 2026 |
| Michael J. Desmarais | Chief Human Resources Officer | 87,725 | 0.02% | Mar 17, 2026 |
| Lisa Ruggles | Senior VP, Global Operations | 174,915 | 0.04% | Mar 17, 2026 |
| Frank Simuro | Chief Technology Officer | 414,491 | 0.10% | Mar 17, 2026 |
| John W. Hill | Director | 22,993 | 0.01% | Aug 10, 2026 |
| Rachel C. Glaser | Director | 12,419 | 0.00% | Jun 24, 2026 |
| Louise S. Sams | Director | 28,671 | 0.01% | Jun 24, 2026 |
| Christine M. McCarthy | Director | 11,585 | 0.00% | Jun 24, 2026 |
| John L. Berisford | Director | 11,235 | 0.00% | Jun 24, 2026 |
| Robert W. Musslewhite | Director | 26,539 | 0.01% | Jun 24, 2026 |
| Angelique G. Brunner | Director | 18,428 | 0.00% | Jun 24, 2026 |
| Nana Banerjee | Director | – | – | Mar 17, 2026 |
| Michael R. Klein | Director | 1,863,088 | 0.46% | Dec 12, 2024 |
| Christopher J. Nassetta | Director | 275,715 | 0.07% | Dec 2, 2024 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Robin Jack Rossmann Chief Financial Officer | Oct 15, 2026 | Tax withholding | −756 | $32.00 | $24.19K | 85,935 |
| Cynthia Cammett Cann Chief Accounting Officer | Aug 7, 2026 | Sale | −4,788 | $30.78 | $147.37K | 18,822 |
| John W. Hill Director | Aug 5, 2026 | Sale | −3,500 | $30.21 | $105.74K | 22,993 |
| Andrew C. Florance Founder and CEO, Director | Aug 4, 2026 | Buy | +83,300 | $29.89 | $2.49M | 1,806,165 |
| Cynthia Cammett Cann Chief Accounting Officer | Aug 1, 2026 | Tax withholding | −1,077 | $28.76 | $30.97K | 23,610 |
| Frederick G. Saint President, Marketplaces | Aug 1, 2026 | Tax withholding | −1,436 | $28.76 | $41.30K | 278,415 |
| Christian M. Lown Chief Financial Officer | Jul 1, 2026 | Tax withholding | −5,597 | $29.36 | $164.33K | 129,653 |
| John W. Hill Director | Jun 23, 2026 | Award | +8,262 | – | – | 26,493 |
| John L. Berisford Director | Jun 23, 2026 | Award | +8,262 | – | – | 11,235 |
| Christine M. McCarthy Director | Jun 23, 2026 | Award | +8,262 | – | – | 11,585 |
| Angelique G. Brunner Director | Jun 23, 2026 | Award | +8,262 | – | – | 18,428 |
| Robert W. Musslewhite Director | Jun 23, 2026 | Award | +8,262 | – | – | 26,539 |
| Louise S. Sams Director | Jun 23, 2026 | Award | +8,262 | – | – | 28,671 |
| Rachel C. Glaser Director | Jun 23, 2026 | Award | +8,262 | – | – | 12,419 |
| Cynthia Cammett Cann Chief Accounting Officer | Jun 15, 2026 | Tax withholding | −461 | $32.04 | $14.77K | 24,687 |
| Andrew C. Florance President and CEO, Director | May 1, 2026 | Buy | +3,100 | $35.82 | $111.04K | 1,722,865 |
| Andrew C. Florance President and CEO, Director | May 1, 2026 | Buy | +68,330 | $35.17 | $2.40M | 1,719,765 |
| Frank Simuro Chief Technology Officer | Mar 15, 2026 | Tax withholding | −11,107 | $43.63 | $484.60K | 414,491 |
| Michael J. Desmarais Chief Human Resources Officer | Mar 15, 2026 | Tax withholding | −2,873 | $43.63 | $125.35K | 87,725 |
| Gene Boxer General Counsel and Secretary | Mar 15, 2026 | Tax withholding | −428 | $43.63 | $18.67K | 95,517 |
| Lisa Ruggles Senior VP, Global Operations | Mar 15, 2026 | Tax withholding | −2,977 | $43.63 | $129.89K | 174,915 |
| Gene Boxer General Counsel and Secretary | Mar 15, 2026 | Tax withholding | −482 | $43.63 | $21.03K | 95,463 |
| Cynthia Cammett Cann Chief Accounting Officer | Mar 15, 2026 | Tax withholding | −1,194 | $43.63 | $52.09K | 25,148 |
| Cynthia Cammett Cann Chief Accounting Officer | Mar 10, 2026 | Award | +4,374 | – | – | 26,342 |
| Gene Boxer General Counsel and Secretary | Mar 10, 2026 | Award | +21,920 | – | – | 95,945 |
| Andrew C. Florance President and CEO, Director | Mar 10, 2026 | Award | +124,162 | – | – | 1,651,435 |
| Christian M. Lown Chief Financial Officer | Mar 10, 2026 | Award | +12,268 | – | – | 135,250 |
| Michael J. Desmarais Chief Human Resources Officer | Mar 10, 2026 | Award | +17,676 | – | – | 90,598 |
| Louise S. Sams Director | Mar 6, 2026 | Buy | +1,000 | $48.36 | $48.36K | 20,409 |
| Rachel C. Glaser Director | Mar 2, 2026 | Buy | +1,000 | $44.94 | $44.94K | 4,157 |
| Frederick G. Saint President, Marketplaces | Mar 2, 2026 | Buy | +20,000 | $45.33 | $906.60K | 279,851 |
| Gene Boxer General Counsel and Secretary | Mar 1, 2026 | Tax withholding | −4,547 | $44.63 | $202.93K | 74,025 |
| Cynthia Cammett Cann Chief Accounting Officer | Mar 1, 2026 | Tax withholding | −1,385 | $44.63 | $61.81K | 21,968 |
| Michael J. Desmarais Chief Human Resources Officer | Mar 1, 2026 | Tax withholding | −6,353 | $44.63 | $283.53K | 72,922 |
| Frederick G. Saint President, Marketplaces | Mar 1, 2026 | Tax withholding | −11,096 | $44.63 | $495.21K | 259,851 |
| Frank Simuro Chief Technology Officer | Mar 1, 2026 | Tax withholding | −18,702 | $44.63 | $834.67K | 425,598 |
| Christian M. Lown Chief Financial Officer | Mar 1, 2026 | Tax withholding | −7,175 | $44.63 | $320.22K | 122,982 |
| Lisa Ruggles Senior VP, Global Operations | Mar 1, 2026 | Tax withholding | −8,931 | $44.63 | $398.59K | 177,892 |
| Andrew C. Florance President and CEO, Director | Mar 1, 2026 | Tax withholding | −59,593 | $44.63 | $2.66M | 1,527,273 |
| Andrew C. Florance President and CEO, Director | Feb 27, 2026 | Buy | +55,720 | $44.52 | $2.48M | 1,586,866 |
| Lisa Ruggles Senior VP, Global Operations | Feb 19, 2026 | Returned to company | −17,583 | – | – | 190,042 |
| Lisa Ruggles Senior VP, Global Operations | Feb 19, 2026 | Tax withholding | −3,219 | $49.07 | $157.96K | 186,823 |
| Frank Simuro Chief Technology Officer | Feb 19, 2026 | Tax withholding | −4,421 | $49.07 | $216.94K | 444,300 |
| Frank Simuro Chief Technology Officer | Feb 19, 2026 | Returned to company | −30,727 | – | – | 448,721 |
| Andrew C. Florance President and CEO, Director | Feb 19, 2026 | Tax withholding | −19,221 | $49.07 | $943.17K | 1,531,146 |
| Andrew C. Florance President and CEO, Director | Feb 19, 2026 | Returned to company | −104,983 | – | – | 1,550,367 |
| Frederick G. Saint President, Marketplaces | Feb 19, 2026 | Tax withholding | −2,149 | $49.07 | $105.45K | 270,947 |
| Frederick G. Saint President, Marketplaces | Feb 19, 2026 | Returned to company | −17,583 | – | – | 273,096 |
| Frank Simuro Chief Technology Officer | Feb 15, 2026 | Tax withholding | −4,151 | $44.99 | $186.75K | 479,448 |
| Lisa Ruggles Senior VP, Global Operations | Feb 15, 2026 | Tax withholding | −3,576 | $44.99 | $160.88K | 207,625 |
| Andrew C. Florance President and CEO, Director | Feb 15, 2026 | Tax withholding | −17,482 | $44.99 | $786.52K | 1,655,350 |
| Frederick G. Saint President, Marketplaces | Feb 15, 2026 | Tax withholding | −2,424 | $44.99 | $109.06K | 290,679 |
| Cynthia Cammett Cann Chief Accounting Officer | Nov 13, 2025 | Sale | −1,841 | $68.79 | $126.64K | 23,211 |
| John W. Hill Director | Nov 13, 2025 | Sale | −2,250 | $68.68 | $154.53K | 18,231 |
| John W. Hill Director | Sep 9, 2025 | Award | +3,177 | – | – | 20,481 |
| Rachel C. Glaser Director | Sep 9, 2025 | Award | +3,143 | – | – | 3,143 |
| Robert W. Musslewhite Director | Sep 9, 2025 | Award | +3,121 | – | – | 18,277 |
| Louise S. Sams Director | Sep 9, 2025 | Award | +3,291 | – | – | 19,409 |
| John L. Berisford Director | Sep 9, 2025 | Award | +2,973 | – | – | 2,973 |
| Christine M. McCarthy Director | Sep 9, 2025 | Award | +2,973 | – | – | 2,973 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Short interest
Shares sold short and not yet bought back, as of Oct 30, 2026 (FINRA, reported twice a month)
Short % of float
3.15%
12M shares short
Days to cover
1.7
At 7M shares a day
Change since last report
-16.6%
From 15M shares
Short volume, 20 days
30.4%
Of volume reported to FINRA
Shares sold short, last 12 months
Short sale volume counts trades marked short on any given day, including market-maker hedging, so it runs far higher than the share of CoStar's stock actually held short. Settlement fails (shares not delivered on time) peaked at 79,443 shares on Sep 1, 2026 over the last 90 days.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| John W. Hill Director | Aug 5, 2026 | 3,500 | $106.07K | Aug 5, 2026 | Payment for services rendered |
| John W. Hill Director, Member of immediate family of any of the foregoing | Nov 13, 2025 | 2,250 | $151.92K | Nov 13, 2025 | Payment for Services Rendered |
| Frederick G. Saint Officer | Aug 28, 2025 | 25,000 | $2.26M | Aug 28, 2025 | Restricted Stock |
| Frederick G. Saint Officer | Jul 28, 2025 | 25,000 | $2.33M | Jul 28, 2025 | Restricted Stock |
| Frederick G. Saint Officer, Director | Jun 11, 2025 | 25,000 | $2.03M | Jun 11, 2025 | Performance Shares |
| Michael R. Klein Former Board Member, retired less than 90 days ago | May 12, 2025 | 267,936 | $20.15M | May 12, 2025 | Founder's Shares |
| Michael R. Klein Former Board Member, retired less than 90 days ago | May 9, 2025 | 32,064 | $2.42M | May 9, 2025 | Founder's Shares |
| John W. Hill Director | Dec 10, 2024 | 2,735 | $215.10K | Dec 10, 2024 | Payment for Services Rendered |
| Christopher J Nasseta Director | Nov 27, 2024 | 1,681 | $134.35K | Nov 27, 2024 | Acquired as compensation -- Restricted Stock Awards |
| Michael J. Desmarais Officer | Nov 26, 2024 | 5,500 | $439.32K | Nov 26, 2024 | Restricted Stock |
| Michael R. Klein Director | Oct 25, 2024 | 71,633 | $5.30M | Oct 25, 2024 | Founder's Shares |
| John W. Hill Director | Jul 30, 2024 | 1,325 | $103.00K | Jul 30, 2024 | payment for services rendered |
| Frederick G. Saint Officer | May 16, 2024 | 2,500 | $221.07K | May 16, 2024 | Restricted Stock |
| Lisa Ruggles Officer | May 9, 2024 | 20,000 | $1.82M | May 9, 2024 | Restricted Stock |
| Scott T. Wheeler Officer | Apr 26, 2024 | 122,736 | $11.37M | Apr 26, 2024 | Stock Option Exercise |
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