DOSSIER · 13F Holders · Q2 2026

ALLIANT ENERGY CORP

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

CUSIP 018802958·4 13F holders·last filed Jun 30, 2026
Market cap
13F value held
$2M
visible holders
Holders
4
filers reporting
Concentration
48.33%
GROUP ONE TRADING LLC #1
top holder share
AI Holders Summary · Q2 2026

4 institutions reported ALLIANT ENERGY CORP in Q2 2026. GROUP ONE TRADING LLC leads at 48.3% of the visible book.

Top holders

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

#HolderValueShares% port.Quarter
01
GROUP ONE TRADING LLC
CIK 0000932540
$771K10K0.00%Q2 2026
02
IMC-Chicago, LLC
CIK 0001452861· Market maker
$473K6K0.00%Q2 2026
03
SIMPLEX TRADING, LLC
CIK 0001488542
$351K5K0.00%Q2 2026
04
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00Q2 2025