DOSSIER · 13F Holders · Q3 2026

AFFILIATED MANAGERS GROUP

3 institutions still hold AFFILIATED MANAGERS GROUP as of Q3 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 008252908·3 13F holders·last filed Sep 30, 2026
Market cap
—
13F value held
$987K
visible holders
Holders
3
filers reporting
Concentration
77.78%
IMC-Chicago, LLC #1
top holder share
AI Holders Summary · Q3 2026

3 institutions reported AFFILIATED MANAGERS GROUP in Q3 2026. IMC-Chicago, LLC leads at 77.8% 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
$768K2K0.00%Q3 2026
02
SIMPLEX TRADING, LLC
CIK 0001488542
$219K6000.00%Q3 2026
03
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00—Q2 2025