COSTAR GROUP INC CSGP
COM · Common Stock · CUSIP 22160N109 · ISIN US22160N1090
American technology company
- SectorIndustrials
- IndustryServices-Business Services, NEC
- HeadquartersArlington, VA
- Founded1987
- Websitecostargroup.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($35.6m this quarter). Holder counts are more reliable. Shares outstanding: 423.7m as of 2025-07-21, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $80.43. Options: 26 managers hold calls ($189.9m notional), 20 hold puts ($103.8m).
Trends to Q2 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 633 |
| Q4 2022 | 702 |
| Q1 2023 | 691 |
| Q2 2023 | 714 |
| Q3 2023 | 690 |
| Q4 2023 | 737 |
| Q1 2024 | 767 |
| Q2 2024 | 768 |
| Q3 2024 | 774 |
| Q4 2024 | 806 |
| Q1 2025 | 859 |
| Q2 2025 | 874 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2023 | 334 | 337 |
| Q4 2023 | 349 | 313 |
| Q1 2024 | 383 | 321 |
| Q2 2024 | 370 | 375 |
| Q3 2024 | 390 | 362 |
| Q4 2024 | 394 | 373 |
| Q1 2025 | 504 | 339 |
| Q2 2025 | 445 | 391 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2024 | $113.3m | $58.2m | 0.51 |
| Q4 2024 | $94.7m | $80.7m | 0.85 |
| Q1 2025 | $336.9m | $118.9m | 0.35 |
| Q2 2025 | $189.9m | $103.8m | 0.55 |
Biggest buyers
| JANUS HENDERSON GROUP PLC | Added | +4.0m |
| VIKING GLOBAL INVESTORS LP | New | +3.2m |
| FRANKLIN RESOURCES INC | Added | +1.4m |
| ROYAL BANK OF CANADA | Added | +1.2m |
| Third Point LLC | Added | +1.1m |
| Ion Asset Management Ltd. | Added | +1.0m |
| SG Capital Management LLC | New | +940.2k |
| PARNASSUS INVESTMENTS, LLC | New | +655.4k |
| BAMCO INC /NY/ | Added | +647.4k |
| Capital Research Global Investors | Added | +510.7k |
Biggest sellers
| TOMS Capital Investment Management LP | Sold out | -3.5m |
| BlackRock, Inc. | Reduced | -2.4m |
| MIZUHO MARKETS AMERICAS LLC | Reduced | -1.5m |
| AMERIPRISE FINANCIAL INC | Reduced | -1.4m |
| MACQUARIE GROUP LTD | Reduced | -1.3m |
| VOYA INVESTMENT MANAGEMENT LLC | Reduced | -1.2m |
| Vulcan Value Partners, LLC | Reduced | -1.1m |
| Soroban Capital Partners LP | Sold out | -1.1m |
| BANK OF AMERICA CORP /DE/ | Reduced | -1.0m |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | Reduced | -694.0k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $43.7m543.5k shares |
| GROUP ONE TRADING LLC | Reduced | $32.2m400.8k shares |
| PEAK6 LLC | Added | $19.5m242.0k shares |
| CITADEL ADVISORS LLC | Reduced | $14.2m176.6k shares |
| SIMPLEX TRADING, LLC | Reduced | $11.7m145.9k shares |
| MILLENNIUM MANAGEMENT LLC | Reduced | $11.2m138.8k shares |
| JANE STREET GROUP, LLC | Reduced | $10.4m129.7k shares |
| WOLVERINE TRADING, LLC | Reduced | $9.2m113.8k shares |
| Parallax Volatility Advisers, L.P. | New | $8.4m105.0k shares |
| IMC-Chicago, LLC | Reduced | $5.8m71.8k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $29.5m366.9k shares |
| MILLENNIUM MANAGEMENT LLC | Reduced | $15.7m195.6k shares |
| PEAK6 LLC | New | $12.6m156.6k shares |
| Schonfeld Strategic Advisors LLC | Unchanged | $8.0m100.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $7.1m88.1k shares |
| Balyasny Asset Management L.P. | New | $6.6m82.5k shares |
| GROUP ONE TRADING LLC | Reduced | $5.9m73.3k shares |
| WOLVERINE TRADING, LLC | Added | $4.4m54.0k shares |
| CITADEL ADVISORS LLC | Reduced | $3.4m42.0k shares |
| CAPSTONE INVESTMENT ADVISORS, LLC | Reduced | $2.5m31.4k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| VANGUARD PORTFOLIO MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 9.1% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 7.5% |
| BlackRock, Inc. 13G · institution filed 2025-04-23 | 7.5% |
| BAMCO INC /NY/ 13G · institution new · filed 2026-08-14 | 5.3% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-26; now reported by VANGUARD PORTFOLIO MANAGEMENT LLC)
Insider purchases and sales in Q2 2025
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q3 2023 | 0 | — | 0 | — | — |
| Q4 2023 | 0 | — | 2 | $370.7k | — |
| Q1 2024 | 0 | — | 0 | — | — |
| Q2 2024 | 0 | — | 4 | $13.8m | — |
| Q3 2024 | 0 | — | 2 | $197.4k | — |
| Q4 2024 | 1 | $1.1m | 5 | $6.2m | — |
| Q1 2025 | 0 | — | 1 | $139.7k | — |
| Q2 2025 | 0 | — | 1 | $2.0m | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-06-11 | SAINT FREDERICK G. President, Marketplaces | Sold | $2.0m25.0k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2025
| Manager | Shares | Change |
|---|---|---|
| VANGUARD GROUP INC 0.09% of their portfolio | 68.8m $5.5bn | Added +420.8k |
| BlackRock, Inc. 0.05% of their portfolio | 35.0m $2.8bn | Reduced -2.4m |
| BAMCO INC /NY/ 4.29% of their portfolio | 19.7m $1.6bn | Added +647.4k |
| PRINCIPAL FINANCIAL GROUP INC 0.79% of their portfolio | 18.6m $1.5bn | Reduced -361.2k |
| STATE STREET CORP 0.05% of their portfolio | 17.7m $1.4bn | Added +158.5k |
| Capital International Investors 0.21% of their portfolio | 14.8m $1.2bn | Added +149.6k |
| GEODE CAPITAL MANAGEMENT, LLC 0.07% of their portfolio | 12.4m $989.9m | Added +290.4k |
| AKRE CAPITAL MANAGEMENT LLC 7.33% of their portfolio | 9.3m $748.5m | Reduced -4.4k |
| BAILLIE GIFFORD & CO 0.51% of their portfolio | 8.5m $686.6m | Added +104.2k |
| MORGAN STANLEY 0.04% of their portfolio | 7.4m $595.9m | Reduced -498.6k |
| POLEN CAPITAL MANAGEMENT LLC 1.71% of their portfolio | 6.9m $556.7m | Added +322.0k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.17% of their portfolio | 6.6m $529.5m | Reduced -33.8k |
| T. Rowe Price Investment Management, Inc. 0.33% of their portfolio | 6.5m $522.1m | Added +75.9k |
| MIZUHO MARKETS AMERICAS LLC 15.55% of their portfolio | 5.9m $470.9m | Reduced -1.5m |
| NORGES BANK 0.05% of their portfolio | 5.3m $426.8m | Added +38.8k |
| BANK OF AMERICA CORP /DE/ 0.03% of their portfolio | 5.1m $412.2m | Reduced -1.0m |
| Bank of New York Mellon Corp 0.07% of their portfolio | 4.8m $389.5m | Reduced -689.1k |
| MACQUARIE GROUP LTD 0.48% of their portfolio | 4.8m $388.7m | Reduced -1.3m |
| UBS Group AG 0.08% of their portfolio | 4.7m $378.5m | Reduced -31.5k |
| Invesco Ltd. 0.06% of their portfolio | 4.4m $356.9m | Added +132.9k |
| JANUS HENDERSON GROUP PLC 0.16% of their portfolio | 4.0m $324.5m | Added +4.0m |
| Capital Research Global Investors 0.06% of their portfolio | 3.9m $316.1m | Added +510.7k |
| NORTHERN TRUST CORP 0.04% of their portfolio | 3.9m $310.8m | Reduced -161.3k |
| Vulcan Value Partners, LLC 5.45% of their portfolio | 3.7m $309.1m | Reduced -1.1m |
| FRANKLIN RESOURCES INC 0.07% of their portfolio | 3.4m $276.6m | Added +1.4m |
| TIGER GLOBAL MANAGEMENT LLC 0.77% of their portfolio | 3.2m $260.9m | Unchanged |
| VIKING GLOBAL INVESTORS LP 0.75% of their portfolio | 3.2m $258.8m | New |
| Amundi 0.09% of their portfolio | 3.2m $260.4m | Reduced -197.8k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.04% of their portfolio | 3.1m $248.6m | Added +60.8k |
| Third Point LLC 3.26% of their portfolio | 3.1m $248.0m | Added +1.1m |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.05% of their portfolio | 3.0m $239.7m | Added +430.6k |
| BLAIR WILLIAM & CO/IL 0.64% of their portfolio | 2.9m $230.8m | Reduced -32.4k |
| BROWN ADVISORY INC 0.28% of their portfolio | 2.7m $215.1m | Reduced -346.7k |
| ROYAL BANK OF CANADA 0.02% of their portfolio | 2.5m $205.0m | Added +1.2m |
| Legal & General Group Plc 0.05% of their portfolio | 2.5m $201.4m | Added +120.7k |
| JPMORGAN CHASE & CO 0.01% of their portfolio | 2.3m $184.2m | Reduced -195.0k |
| DF DENT & CO INC 2.32% of their portfolio | 2.3m $182.5m | Reduced -96.8k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.44% of their portfolio | 2.3m $182.1m | Reduced -215.5k |
| GOLDMAN SACHS GROUP INC 0.03% of their portfolio | 2.2m $175.5m | Reduced -517.2k |
| DIMENSIONAL FUND ADVISORS LP 0.04% of their portfolio | 2.2m $174.4m | Added +22.3k |
| Fayez Sarofim & Co 0.42% of their portfolio | 2.2m $173.4m | Added +11.8k |
| RGM Capital, LLC 6.91% of their portfolio | 2.1m $170.7m | Reduced -104.8k |
| MACKENZIE FINANCIAL CORP 0.19% of their portfolio | 1.9m $149.8m | Reduced -599.6k |
| CIBC Private Wealth Group LLC 0.26% of their portfolio | 1.8m $147.6m | Added +9.3k |
| RIVERBRIDGE PARTNERS LLC 2.27% of their portfolio | 1.8m $141.0m | Reduced -112.3k |
| ENVESTNET ASSET MANAGEMENT INC 0.04% of their portfolio | 1.7m $139.8m | Reduced -46.0k |
| BECK MACK & OLIVER LLC 2.65% of their portfolio | 1.7m $138.8m | Reduced -83.9k |
| DEUTSCHE BANK AG\ 0.05% of their portfolio | 1.5m $122.7m | Added +296.7k |
| FEDERATED HERMES, INC. 0.22% of their portfolio | 1.5m $118.2m | Added +5.0k |
| Harding Loevner LP 0.79% of their portfolio | 1.5m $118.0m | Added +27.0k |
| ShawSpring Partners LLC 13.76% of their portfolio | 1.4m $109.0m | Added +207.8k |
| WELLS FARGO & COMPANY/MN 0.02% of their portfolio | 1.3m $107.0m | Added +98.4k |
| FMR LLC 0.01% of their portfolio | 1.3m $104.2m | Reduced -342.8k |
| KENSICO CAPITAL MANAGEMENT CORP 1.98% of their portfolio | 1.3m $103.1m | Reduced -48.9k |
| BNP PARIBAS FINANCIAL MARKETS 0.08% of their portfolio | 1.3m $102.9m | Reduced -381.6k |
| Swiss National Bank 0.06% of their portfolio | 1.3m $102.7m | Added +88.6k |
| VOYA INVESTMENT MANAGEMENT LLC 0.10% of their portfolio | 1.2m $99.0m | Reduced -1.2m |
| Bares Capital Management, Inc. 9.48% of their portfolio | 1.2m $97.7m | Added +81.7k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 1.2m $96.1m | Added +152.5k |
| BARCLAYS PLC 0.04% of their portfolio | 1.2m $94.2m | Added +127.6k |
| Ion Asset Management Ltd. 5.68% of their portfolio | 1.2m $94.1m | Added +1.0m |
| Nuveen, LLC 0.02% of their portfolio | 1.1m $87.0m | Added +37.4k |
| AMERIPRISE FINANCIAL INC 0.02% of their portfolio | 1.1m $86.7m | Reduced -1.4m |
| Sumitomo Mitsui Trust Group, Inc. 0.05% of their portfolio | 1.0m $82.1m | Added +24.3k |
| Focus Partners Wealth 0.17% of their portfolio | 990.5k $79.6m | Added +6.7k |
| Chicago Capital, LLC 1.91% of their portfolio | 964.3k $77.5m | Added +20.3k |
| SG Capital Management LLC 6.43% of their portfolio | 940.2k $75.6m | New |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.06% of their portfolio | 926.0k $74.5m | Added +58.5k |
| Baird Financial Group, Inc. 0.13% of their portfolio | 920.8k $74.0m | Reduced -41.5k |
| D. E. Shaw & Co., Inc. 0.07% of their portfolio | 916.4k $73.7m | Reduced -304 |
| Pictet Asset Management Holding SA 0.07% of their portfolio | 915.1k $73.6m | Reduced -14.0k |
| CITIGROUP INC 0.05% of their portfolio | 832.7k $66.9m | Added +133.3k |
| TimesSquare Capital Management, LLC 0.94% of their portfolio | 810.2k $65.1m | Added +57.3k |
| Spyglass Capital Management LLC 3.81% of their portfolio | 803.3k $64.6m | Added +307.4k |
| AMERICAN CAPITAL MANAGEMENT INC 2.65% of their portfolio | 796.0k $64.0m | Reduced -142.2k |
| KAYNE ANDERSON RUDNICK INVESTMENT MANAGEMENT LLC 0.15% of their portfolio | 782.7k $62.9m | Reduced -49.9k |
| RHUMBLINE ADVISERS 0.05% of their portfolio | 782.2k $62.9m | Added +13.8k |
| Stephens Investment Management Group LLC 0.82% of their portfolio | 773.3k $62.2m | Added +34.4k |
| Ensign Peak Advisors, Inc 0.11% of their portfolio | 771.4k $62.0m | Reduced -63.8k |
| WEITZ INVESTMENT MANAGEMENT, INC. 3.31% of their portfolio | 765.6k $61.6m | Reduced -146.0k |
| CI INVESTMENTS INC. 0.21% of their portfolio | 708.5k $57.0m | Reduced -18.7k |
| HSBC HOLDINGS PLC 0.04% of their portfolio | 708.4k $56.9m | Reduced -51.9k |
| PEREGRINE CAPITAL MANAGEMENT LLC 1.70% of their portfolio | 700.5k $56.3m | Reduced -38.9k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.06% of their portfolio | 698.3k $56.1m | Added +1.9k |
| California Public Employees Retirement System 0.04% of their portfolio | 686.9k $55.2m | Added +56.3k |
| TD Asset Management Inc 0.05% of their portfolio | 682.2k $54.9m | Reduced -32.4k |
| RAYMOND JAMES FINANCIAL INC 0.02% of their portfolio | 661.9k $53.2m | Reduced -25.0k |
| ProShare Advisors LLC 0.11% of their portfolio | 661.4k $53.2m | Added +43.7k |
| PARNASSUS INVESTMENTS, LLC 0.12% of their portfolio | 655.4k $52.7m | New |
| SEI INVESTMENTS CO 0.06% of their portfolio | 654.6k $52.6m | Reduced -26.2k |
| FIRST TRUST ADVISORS LP 0.04% of their portfolio | 616.5k $49.6m | Added +339.5k |
| Candlestick Capital Management LP 1.59% of their portfolio | 596.1k $47.9m | Reduced -582.5k |
| Douglas Lane & Associates, LLC 0.68% of their portfolio | 584.3k $47.0m | Added +27.6k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.03% of their portfolio | 558.9k $44.9m | Added +66.7k |
| Telemark Asset Management, LLC 4.69% of their portfolio | 550.0k $44.2m | Added +50.0k |
| National Pension Service 0.04% of their portfolio | 541.6k $43.5m | Added +4.5k |
| NATIXIS ADVISORS, LLC 0.07% of their portfolio | 537.7k $43.2m | Reduced -56.9k |
| CANADA PENSION PLAN INVESTMENT BOARD 0.04% of their portfolio | 534.5k $43.0m | Added +67.4k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.39% of their portfolio | 527.5k $42.4m | Added +88.1k |
| ThornTree Capital Partners LP 6.86% of their portfolio | 512.5k $41.2m | Added +119.3k |