DOSSIER · 13F Holders · Q2 2026

GALLAGHER ARTHUR J & CO

5 institutions still hold GALLAGHER ARTHUR J & CO as of Q2 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 363576909·5 13F holders·last filed Jun 30, 2026
Market cap
13F value held
$20M
visible holders
Holders
5
filers reporting
Concentration
58.00%
IMC-Chicago, LLC #1
top holder share
AI Holders Summary · Q2 2026

5 institutions reported GALLAGHER ARTHUR J & CO in Q2 2026. IMC-Chicago, LLC leads at 58.0% 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
$12M50K0.00%Q2 2026
02
HRT FINANCIAL LP
CIK 0001475597
$5M20K0.02%Q4 2025
03
SIMPLEX TRADING, LLC
CIK 0001488542
$2M8K0.00%Q2 2026
04
GROUP ONE TRADING LLC
CIK 0000932540
$1M6K0.00%Q2 2026
05
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00Q2 2025