DOSSIER · 13F Holders · Q3 2026

QUANTUM CORP

4 institutions still hold QUANTUM CORP as of Q3 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 747906900·4 13F holders·last filed Sep 30, 2026
Market cap
—
13F value held
$5M
visible holders
Holders
4
filers reporting
Concentration
80.96%
IMC-Chicago, LLC #1
top holder share
AI Holders Summary · Q3 2026

4 institutions reported QUANTUM CORP in Q3 2026. IMC-Chicago, LLC leads at 81.0% 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
$4M139K0.00%Q3 2026
02
SIMPLEX TRADING, LLC
CIK 0001488542
$885K28K0.00%Q3 2026
03
GROUP ONE TRADING LLC
CIK 0000932540
$149K5K0.00%Q3 2026
04
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00—Q2 2025