Generation Bio Co. - Common Stock (GBIO) Institutional Ownership

13F Institutional Holders and Ownership History from Q2 2025 to Q3 2025

Type / Class
Equity / Common Stock
Symbol
GBIO on Nasdaq
Shares outstanding
6,697,238
Price per share
$5.51
All holders as of 30 Sep 2025
Q3 2025
Total 13F shares
3,110,648
Total reported value
$19,037,334
% of total 13F portfolios
0%
Share change
+2,993,372
Value change
+$18,321,864
Number of holders
35
Price from insider filings
$5.51
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of Generation Bio Co. - Common Stock (GBIO) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
PRICE T ROWE ASSOCIATES INC /MD/ 8.6% -31% $3,449,198 -$47,157,216 576,789 -93% T. Rowe Price Associates, Inc. 30 Sep 2025
SymBiosis Capital Partners, LLC 6.3% $2,523,117 421,926 SymBiosis Capital Partners, LLC 30 Sep 2025
RENAISSANCE TECHNOLOGIES LLC 5.1% $2,058,693 344,263 Renaissance Technologies LLC 01 Jul 2025

As of 30 Sep 2025, 35 institutional investors reported holding 3,110,648 shares of Generation Bio Co. - Common Stock (GBIO). This represents 46% of the company’s total 6,697,238 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of Generation Bio Co. - Common Stock (GBIO) together control 46% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.

Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
PRICE T ROWE ASSOCIATES INC /MD/ 8.6% 576,789 0% $3,531,000
RENAISSANCE TECHNOLOGIES LLC 5.1% 344,263 0% $2,106,890
Siren, L.L.C. 4.4% 296,892 0.07% $1,816,979
VANGUARD GROUP INC 3.4% 229,833 0% $1,406,578
MARSHALL WACE, LLP 3.3% 218,461 +88% 0% $1,336,981
BAKER BROS. ADVISORS LP 2.9% 194,493 0.01% $1,190,297
MORGAN STANLEY 2.5% 164,270 0% $1,005,333
UBS Group AG 2.2% 148,721 0% $910,172
ACADIAN ASSET MANAGEMENT LLC 1.9% 127,506 0% $779,000
GOLDMAN SACHS GROUP INC 1.8% 118,583 0% $725,728
Yiheng Capital Management, L.P. 1.6% 105,524 0.21% $645,807
CANTOR FITZGERALD, L. P. 1.5% 99,000 0.01% $605,880
MILLENNIUM MANAGEMENT LLC 1.5% 97,354 0% $595,806
BANK OF AMERICA CORP /DE/ 1.3% 84,817 0% $519,079
BlackRock, Inc. 0.9% 60,116 0% $367,910
GEODE CAPITAL MANAGEMENT, LLC 0.74% 49,805 0% $304,890
CITADEL ADVISORS LLC 0.7% 47,197 0% $288,846
TD Asset Management Inc 0.4% 26,708 0% $163,453
ADAR1 Capital Management, LLC 0.33% 22,144 0.01% $135,521
STATE STREET CORP 0.3% 19,993 0% $122,357
MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.21% 14,398 0% $88,116
NORTHERN TRUST CORP 0.2% 13,306 0% $81,433
FMR LLC 0.19% 13,031 0% $79,750
TWO SIGMA INVESTMENTS, LP 0.19% 12,442 0% $76,145
XTX Topco Ltd 0.17% 11,344 0% $69,425

Institutional Holders of Generation Bio Co. - Common Stock (GBIO) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q3 3,110,648 $19,037,334 +$18,321,864 $6.12 35
2025 Q2 117,122 $37,480 +$37,479 $0.32 3