DOSSIER · 13F Holders · Q2 2026

GARTNER INC

4 institutions still hold GARTNER INC as of Q2 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 366651907·4 13F holders·last filed Jun 30, 2026
Market cap
13F value held
$17M
visible holders
Holders
4
filers reporting
Concentration
64.00%
IMC-Chicago, LLC #1
top holder share
AI Holders Summary · Q2 2026

4 institutions reported GARTNER INC in Q2 2026. IMC-Chicago, LLC leads at 64.0% of the visible book.

Top holders

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

#HolderValueShares% port.Quarter
01
IMC-Chicago, LLC
CIK 0001452861· Market maker
$11M86K0.00%Q2 2026
02
SIMPLEX TRADING, LLC
CIK 0001488542
$6M46K0.00%Q2 2026
03
GROUP ONE TRADING LLC
CIK 0000932540
$337K3K0.00%Q2 2026
04
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00Q2 2025