DOSSIER · 13F Holders · Q2 2026

SELLAS LIFE SCIENCES GROUP I

6 institutions still hold SELLAS LIFE SCIENCES GROUP I as of Q2 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 81642T959·6 13F holders·last filed Jun 30, 2026
Market cap
13F value held
$29M
visible holders
Holders
6
filers reporting
Concentration
64.54%
GROUP ONE TRADING LLC #1
top holder share
AI Holders Summary · Q2 2026

6 institutions reported SELLAS LIFE SCIENCES GROUP I in Q2 2026. GROUP ONE TRADING LLC leads at 64.5% 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
$19M1.3M0.03%Q2 2026
02
SIMPLEX TRADING, LLC
CIK 0001488542
$7M481K0.00%Q2 2026
03
Rosalind Advisors, Inc.
CIK 0001622627
$2M569K0.86%Q2 2026
04
NATIONAL BANK OF CANADA /FI/
CIK 0000926171
$840K5690.00%Q2 2026
05
Marathon Trading Investment Management LLC
CIK 0001572748
$148K10K0.00%Q2 2026
06
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00Q2 2025