Company · Ownership research

COSTAR GROUP, INC. CSGP

CIK 0001057352 · CUSIP 22160N109

Insider trading Initial holdings Institutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 22160N109 (CSGP), not CUSIP 22160N909 (CSGP), CUSIP 22160N959 (CSGP), and does not merge CUSIPs.

This page lists the top 20 of 860 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	VANGUARD GROUP INC CIK 102909 · View history	$5.42B 68,426,711 shares	0.10%	+2.71M(+4.10%)Added	SEC filing ↗ May 9, 2025	▾
02	BlackRock, Inc. CIK 2012383 · View history	$2.97B 37,457,618 shares	0.06%	-658.08K(-1.70%)Reduced	SEC filing ↗ May 2, 2025	▾
03	BAMCO INC /NY/ CIK 1017918 · View history	$1.51B 19,032,522 shares	4.43%	-171.04K(-0.90%)Reduced	SEC filing ↗ May 15, 2025	▾
04	PRINCIPAL FINANCIAL GROUP INC CIK 1126328 · View history	$1.51B 19,007,873 shares	0.85%	-178.40K(-0.90%)Reduced	SEC filing ↗ Apr 28, 2025	▾
05	STATE STREET CORP CIK 93751 · View history	$1.39B 17,574,429 shares	0.06%	+542.55K(+3.20%)Added	SEC filing ↗ May 15, 2025	▾
06	Capital International Investors CIK 1562230 · View history	$1.16B 14,669,837 shares	0.23%	+637.47K(+4.50%)Added	SEC filing ↗ May 12, 2025	▾
07	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$953.41M 12,067,436 shares	0.07%	+591.68K(+5.20%)Added	SEC filing ↗ May 13, 2025	▾
08	AKRE CAPITAL MANAGEMENT LLC CIK 1112520 · View history	$737.92M 9,313,592 shares	7.09%	-288(0.00%)Reduced	SEC filing ↗ May 13, 2025	▾
09	BAILLIE GIFFORD & CO CIK 1088875 · View history	$668.40M 8,436,199 shares	0.58%	+524.60K(+6.60%)Added	SEC filing ↗ May 7, 2025	▾
10	MORGAN STANLEY CIK 895421 · View history	$626.72M 7,910,143 shares	0.04%	+3.57M(+82.30%)Added	SEC filing ↗ May 15, 2025	▾
11	MIZUHO MARKETS AMERICAS LLC CIK 1825516 · View history	$586.40M 7,401,273 shares	12.73%	+7.40MNew	SEC filing ↗ May 12, 2025	▾
12	MASSACHUSETTS FINANCIAL SERVICES CO /MA/ CIK 912938 · View history	$524.46M 6,619,472 shares	0.17%	-474.27K(-6.70%)Reduced	SEC filing ↗ May 2, 2025	▾
13	POLEN CAPITAL MANAGEMENT LLC CIK 1034524 · View history	$523.06M 6,601,800 shares	1.64%	+104.61K(+1.60%)Added	SEC filing ↗ May 12, 2025	▾
14	T. Rowe Price Investment Management, Inc. CIK 1897612 · View history	$508.51M 6,418,209 shares	0.34%	+2.31K(0.00%)Added	SEC filing ↗ May 14, 2025	▾
15	MACQUARIE GROUP LTD CIK 1418333 · Amended · View history	$489.39M 6,176,880 shares	0.61%	-1.15M(-15.70%)Reduced	SEC filing ↗ Aug 14, 2025	▾
16	BANK OF AMERICA CORP /DE/ CIK 70858 · View history	$486.41M 6,139,226 shares	0.04%	+2.57M(+71.80%)Added	SEC filing ↗ May 15, 2025	▾
17	Bank of New York Mellon Corp CIK 1390777 · View history	$438.44M 5,533,767 shares	0.09%	-11.30K(-0.20%)Reduced	SEC filing ↗ Apr 29, 2025	▾
18	NORGES BANK CIK 1374170 · Amended · View history	$417.50M 5,269,486 shares	0.06%	-188.75K(-3.50%)Reduced	SEC filing ↗ May 13, 2025	▾
19	Vulcan Value Partners, LLC CIK 1556785 · View history	$382.95M 4,833,477 shares	7.19%	-265.96K(-5.20%)Reduced	SEC filing ↗ May 8, 2025	▾
20	UBS Group AG CIK 1610520 · View history	$375.51M 4,739,479 shares	0.08%	+3.23M(+214.90%)Added	SEC filing ↗ May 13, 2025	▾

Showing 20 / 860 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

860

Cancelled or null records excluded

Disclosed shares

428,840,842

Not deduplicated across managers

Disclosed value

$33.95B

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

COSTAR GROUP, INC. · Q1 2025

Explore all 860 reporting institutions.

This page includes 20 of 860 reporting institutions. Log in to look up the full history beyond 3 years, use advanced screening & filtering, download CSV, and get the complete set through the Akkru API.

Download CSV
Earlier quarters
Advanced screening & filtering
API & AI access

Already have an account?

＋ New accounts get free API credits to explore data beyond ownership filings.

For AI agents & developers

The initial HTML of this page carries its exact data as script#research-data (JSON): values, units, scope, preview limits and SEC sources. Read it directly, no script or API key needed; script#research-access says what needs an account. This page lists 20 of 860 reporting institutions; totals use the complete disclosed data.

Without an account: the last 3 years, with the row caps stated on the page. A free account opens all history on file on these pages and the CSV of what a page shows. Rows beyond the caps and bulk retrieval go through the authenticated API / MCP / CLI.

MCP  https://api.akkrudata.ai/mcp

akkru_institutional_holdings
{"action":"holders","cusip":"22160N109","quarter":"2025Q1","type":"positions","page_size":100}

Connect to MCP with OAuth and follow the returned pagination. Credits and usage limits depend on the account.

MCP endpoint: https://api.akkrudata.ai/mcp
API / MCP / CLI documentation: /documents
llms.txt: /llms.txt

Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.