Costar Group, Inc.

CSGP

Exchange: Nasdaq
Industry: Services-Business Services, NEC
SEC CIK: 0001057352

SEC filings (opens in a new tab)

In the last 90 days, Costar Group, Inc. insiders filed 1 open-market purchase and 2 sales; 760 institutions reported holding it in 13F filings for Q2 2026, worth $11.7B in total; superinvestors Akre Capital Management and Weitz Investment Management hold it.

13F holders, Q3 2026

Institutional positions in Costar Group, Inc. as of Sep 30, 2026. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Q3 2026 data is still coming in (13F filing deadline: Nov 16, 2026), so these numbers are incomplete.

Institutional holders: 5; −1 vs. Q2 2026
Shares held: 11.3K; −1.94K (−14.6%) vs. Q2 2026
Total value: $310.0K; −$65.5K (−17.4%) vs. Q2 2026
New holders: 0; 3 more added
Sold out: 1; 1 more reduced

754 institutions that held it in Q2 2026 haven't filed for Q3 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q2 2026: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting CSGP on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holders

Value held

Institutions holding CSGP and their total value by quarter
Quarter	Holders	Value
Q2 2026	760	$11.7B
Q1 2026	797	$16.8B
Q4 2025	847	$28.4B
Q3 2025	905	$34.9B
Q2 2025	873	$34.2B
Q1 2025	858	$33.9B
Q4 2024	805	$28.9B
Q3 2024	773	$30.0B
Q2 2024	767	$29.3B
Q1 2024	767	$38.4B
Q4 2023	737	$34.4B
Q3 2023	690	$30.1B
Q2 2023	714	$35.5B
Q1 2023	692	$26.7B
Q4 2022	704	$30.4B
Q3 2022	634	$28.0B
Q2 2022	591	$23.0B
Q1 2022	589	$25.2B
Q4 2021	633	$29.6B
Q3 2021	594	$32.3B
Q2 2021	607	$31.1B
Q1 2021	593	$31.2B

Institutions, Q3 2026

Shares, value and share of portfolio for each institution holding Costar Group, Inc.; share changes are against Q2 2026.

Institutions holding CSGP in Q3 2026
Institution	Shares	Value	% of portfolio	Change in shares	Action
Eastern Bank	1	$27	0.00%	00.0%	Unchanged
Planning Strategies Inc.	57	$1.56K	0.00%	−33−36.7%	Reduced
Massmutual Trust Co FSB	2,365	$64.8K	0.00%	+122+5.4%	Added
CX Institutional	3,299	$90.0K	0.00%	+3,118+1,722.7%	Added
Versant Capital Management, Inc	5,606	$153.6K	0.01%	+2,175+63.4%	Added
Baker Tilly Wealth Management, LLC	0	$0	0.00%	−7,317−100.0%	Sold out
Vanguard Portfolio Management LLC	–	–	–	–	Not filed
BlackRock, Inc.	–	–	–	–	Not filed
Vanguard Capital Management LLC	–	–	–	–	Not filed
Bamco Inc	–	–	–	–	Not filed
State Street Corp	–	–	–	–	Not filed
Capital International Investors	–	–	–	–	Not filed
Baillie Gifford & Co	–	–	–	–	Not filed
Geode Capital Management, LLC	–	–	–	–	Not filed
Akre Capital Management LLCSuperinvestorAkre Capital Management	–	–	–	–	Not filed
Polen Capital Management LLC	–	–	–	–	Not filed
AQR Capital Management LLC	–	–	–	–	Not filed
Jupiter Topco LLC	–	–	–	–	Not filed
Invesco Ltd.	–	–	–	–	Not filed
EdgePoint Investment Group Inc.	–	–	–	–	Not filed
Norges Bank	–	–	–	–	Not filed
Morgan Stanley	–	–	–	–	Not filed
Meritage Group LP	–	–	–	–	Not filed
JPMorgan Chase & Co	–	–	–	–	Not filed
Goldman Sachs Group Inc	–	–	–	–	Not filed
Federated Hermes, Inc.	–	–	–	–	Not filed
Capital Research Global Investors	–	–	–	–	Not filed
Principal Financial Group Inc	–	–	–	–	Not filed
Northern Trust Corp	–	–	–	–	Not filed
Qube Research & Technologies Ltd	–	–	–	–	Not filed
BNP PARIBAS ASSET MANAGEMENT Holding S.A.	–	–	–	–	Not filed
Amundi	–	–	–	–	Not filed
Van Eck Associates Corp	–	–	–	–	Not filed
Massachusetts Financial Services Co	–	–	–	–	Not filed
Charles Schwab Investment Management Inc	–	–	–	–	Not filed
Bank of America Corp	–	–	–	–	Not filed
Spyglass Capital Management LLC	–	–	–	–	Not filed
UBS Asset Management Americas Inc	–	–	–	–	Not filed
Canada Pension Plan Investment Board	–	–	–	–	Not filed
FMR LLC	–	–	–	–	Not filed
Nomura Asset Management International Inc.	–	–	–	–	Not filed
Ensign Peak Advisors, Inc	–	–	–	–	Not filed
UBS Group AG	–	–	–	–	Not filed
Vanguard Fiduciary Trust Co	–	–	–	–	Not filed
Deutsche Bank AG	–	–	–	–	Not filed
Bank of Montreal	–	–	–	–	Not filed
Jane Street Group, LLC	–	–	–	–	Not filed
Beck Mack & Oliver LLC	–	–	–	–	Not filed
Bank of New York Mellon Corp	–	–	–	–	Not filed
Erste Asset Management GmbH	–	–	–	–	Not filed
Thompson Siegel & Walmsley LLC	–	–	–	–	Not filed
Legal & General Group Plc	–	–	–	–	Not filed
BNP Paribas Arbitrage, SA	–	–	–	–	Not filed
HSBC Holdings PLC	–	–	–	–	Not filed
Fiera Capital Corp	–	–	–	–	Not filed
Voloridge Investment Management, LLC	–	–	–	–	Not filed
Envestnet Asset Management Inc	–	–	–	–	Not filed
Dimensional Fund Advisors LP	–	–	–	–	Not filed
Pictet Asset Management Holding SA	–	–	–	–	Not filed
Royal Bank of Canada	–	–	–	–	Not filed
Squarepoint Ops LLC	–	–	–	–	Not filed
Marshall Wace, LLP	–	–	–	–	Not filed
Nuveen, LLC	–	–	–	–	Not filed
DF Dent & Co Inc	–	–	–	–	Not filed
Arrowstreet Capital, Limited Partnership	–	–	–	–	Not filed
Wells Fargo & Company	–	–	–	–	Not filed
Swiss National Bank	–	–	–	–	Not filed
Connor, Clark & Lunn Investment Management Ltd.	–	–	–	–	Not filed
Douglas Lane & Associates, LLC	–	–	–	–	Not filed
Two Sigma Investments, LP	–	–	–	–	Not filed
Riverbridge Partners LLC	–	–	–	–	Not filed
D. E. Shaw & Co., Inc.	–	–	–	–	Not filed
Mitsubishi UFJ Kokusai Asset Management Co., Ltd.	–	–	–	–	Not filed
Colony Group, LLC	–	–	–	–	Not filed
Sumitomo Mitsui Trust Holdings, Inc.	–	–	–	–	Not filed
Man Group plc	–	–	–	–	Not filed
Capital Fund Management S.A.	–	–	–	–	Not filed
Citigroup Inc	–	–	–	–	Not filed
Vanguard Global Advisers, LLC	–	–	–	–	Not filed
Primecap Management Co	–	–	–	–	Not filed
Rhumbline Advisers	–	–	–	–	Not filed
Vanguard Asset Management, Ltd	–	–	–	–	Not filed
Russell Investments Group, Ltd.	–	–	–	–	Not filed
Barclays PLC	–	–	–	–	Not filed
Petrus Trust Company, LTA	–	–	–	–	Not filed
Millennium Management LLC	–	–	–	–	Not filed
Citadel Advisors LLC	–	–	–	–	Not filed
Trexquant Investment LP	–	–	–	–	Not filed
American Capital Management Inc	–	–	–	–	Not filed
Korea Investment CORP	–	–	–	–	Not filed
Peregrine Capital Management LLC	–	–	–	–	Not filed
Price T Rowe Associates Inc	–	–	–	–	Not filed
California State Teachers Retirement System	–	–	–	–	Not filed
Blair William & Co	–	–	–	–	Not filed
Alliancebernstein L.P.	–	–	–	–	Not filed
Gotham Asset Management, LLC	–	–	–	–	Not filed
Tudor Investment Corp Et Al	–	–	–	–	Not filed
Mitsubishi UFJ Trust & Banking Corp	–	–	–	–	Not filed
Quantinno Capital Management LP	–	–	–	–	Not filed
Chicago Capital, LLC	–	–	–	–	Not filed