$CSGP

$31.95 -$1.76 (5.21%) Live

$CSGP Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 405.2M shares outstanding

Who owns CSGP?

By type of holder

Institutions 100.0% Insiders 0.0% Everyone else 0.0%

Concentration Top 10 holders own 49.2%

Vanguard Portfolio Management LLC 9.4% · BlackRock, Inc. 8.4%

Institutional ownership

100.0%

0 pts vs last qtr

Institutional holders

756

-37 vs last qtr

Net shares bought

−1.2M

by institutions in Q2 2026

New / sold out

115 / 152

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Jupiter Topco LLC NEW +7.8M
Aqr Capital Management LLC +7.2M

Biggest sellers in Q2 2026

Principal Financial Group Inc −13.9M
Invesco Ltd. −9.1M

Who is planning to sell?

Notices of proposed sale, last 12 months

$258K

2 notices from 1 person

Shares covered

5.8K

0.00% of the company

Arranged in advance

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

Hill John W Director $258K

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2019–FY2025

+14.9%

+2.33% a year

Each share's claim on the business

−12.9%

shrank without buying or selling a share

Spent on buybacks vs paid in stock

$500M vs $613M

over 7 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years72% 3–5 years8% 1–3 years8% Under 1 year13%

Quarterly turnover

19.2%

of institutional shares changed hands

Top 10 managers, median time held

5 years

Super Investors

Investment managers reporting CSGP on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
VP Vanguard Portfolio Management LLC	37.9M	9.36%	−319.3K (−0.8%)	≤2021	0.1%
Shares held by quarter Peak holding38.2M (Q1'26) Change over 8 quarters+37.9M Share of the company9.360% Vanguard Portfolio Management LLC's full portfolio →
B BlackRock, Inc.	33.8M	8.35%	+5.8K (+0.0%)	≤2021	0.0%
Shares held by quarter Peak holding38.9M (Q3'24) Change over 8 quarters−5.1M Share of the company8.350% BlackRock, Inc.'s full portfolio →

Vanguard Portfolio Management LLC

37.9M

% of company

9.36%

Change vs last qtr

−319.3K (−0.8%)

Held since

≤2021

BlackRock, Inc.

33.8M

% of company

8.35%

Change vs last qtr

+5.8K (+0.0%)

Held since

≤2021

28 more super investors behind a free account

See every manager holding CoStar Group, Inc., how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting CSGP on Form N-PORT; together they hold 56.3% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
VR Vanguard Real Estate Index Fund Vanguard Specialized Funds	$457M	15.9M	3.92%	0.63%	July 31, 2026
BP Baron Partners Fund Baron Select Funds	$445M	15.7M	3.88%	2.46%	June 30, 2026

Vanguard Real Estate Index Fund

Vanguard Specialized Funds

Position value

$457M

% of company

3.92%

% of the fund

0.63%

As of

July 31, 2026

Baron Partners Fund

Baron Select Funds

Position value

$445M

% of company

3.88%

% of the fund

2.46%

As of

June 30, 2026

23 more funds behind a free account

See every fund holding CoStar Group, Inc. and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
FA Florance Andrew C Insider	20.4M	5.03%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company5.030% Florance Andrew C's insider activity →

Florance Andrew C

Insider

20.4M

% of company

5.03%

Change vs last qtr

—

Held since

—

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