13F Insight
DOSSIER · 13F Holders · Q1 2026BellwetherCompounder

COSTAR GROUP INC

8 institutions still hold COSTAR GROUP INC as of Q1 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 22160N909·8 13F holders·last filed Mar 31, 2026
Market cap
—
▲ 7.7%
vs prior quarter
13F value held
$36M
50.0% inst. owned
of float
Holders
8
-124 QoQ
filers reporting
Activity
+88 / −85
+916 added · −898 reduced
this quarter
Concentration
34.22%
LANDMARK INVESTMENT PARTNERS, L.P. #1
top holder share
AI Holders Summary · Q1 2026

8 institutions reported COSTAR GROUP INC in Q1 2026. LANDMARK INVESTMENT PARTNERS, L.P. leads at 34.2% of the visible book. -124 net institutions QoQ — distribution reading.

Top holders

Sorted by position value. Source: SEC EDGAR 13F-HR filings.

#HolderValueShares% port.Quarter
01
LANDMARK INVESTMENT PARTNERS, L.P.
CIK 0002023551
$12M3K8.79%Q1 202602
GROUP ONE TRADING LLC
CIK 0000932540
$11M270K0.02%Q1 202603
IMC-Chicago, LLC
CIK 0001452861· Market maker
$7M179K0.00%Q1 202604
SIMPLEX TRADING, LLC
CIK 0001488542
$4M96K0.00%Q1 202605
Baer Investment Advisory LLC
CIK 0002057153
$1M1K1.19%Q1 202606
JPMORGAN CHASE & CO
CIK 0000019617
$339,3048K0.00%Q1 202607
Itau Unibanco Holding S.A.
CIK 0001132597
$49,4713640.00%Q1 202608
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00—Q2 2025