DOSSIER · 13F Holders · Q4 2025
GBIO

GENERATION BIO C

4 institutions still hold GENERATION BIO C as of Q4 2025. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 37148K209·4 13F holders·last filed Dec 31, 2025
Market cap
13F value held
$3M
visible holders
Holders
4
filers reporting
Concentration
60.85%
Opaleye Management Inc. #1
top holder share
AI Holders Summary · Q4 2025

4 institutions reported GBIO in Q4 2025. Opaleye Management Inc. leads at 60.8% of the visible book.

Top holders

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

#HolderValueShares% port.Quarter
01
Opaleye Management Inc.
CIK 0001595855
$2M310K0.23%Q4 2025
02
MARSHALL WACE, LLP
CIK 0001318757
$797K140K0.00%Q4 2025
03
CITADEL ADVISORS LLC
CIK 0001423053
$268K47K0.00%Q4 2025
04
TWO SIGMA ADVISERS, LP
CIK 0001478735
$68K12K0.00%Q4 2025
Insiders at GENERATION BIO C
Mcdonough GeoffConway Kevin JohnSamayoa PhillipPaone AntoinetteHowze YalondaNicholson Donald WilliamAppelhans DannielleStehman-Breen Catherine