DOSSIER · 13F Holders · Q2 2026

MAGNITE INC

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

CUSIP 55955D900·5 13F holders·last filed Jun 30, 2026
Market cap
13F value held
$10M
visible holders
Holders
5
filers reporting
Concentration
50.98%
IMC-Chicago, LLC #1
top holder share
AI Holders Summary · Q2 2026

5 institutions reported MAGNITE INC in Q2 2026. IMC-Chicago, LLC leads at 51.0% 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
$5M263K0.00%Q2 2026
02
GROUP ONE TRADING LLC
CIK 0000932540
$3M184K0.00%Q2 2026
03
SIMPLEX TRADING, LLC
CIK 0001488542
$1M68K0.00%Q2 2026
04
Northwest & Ethical Investments L.P.
CIK 0002033536
$15K10K0.00%Q2 2026
05
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00Q2 2025