| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| PRICE T ROWE ASSOCIATES INC /MD/ | 8.6% | -31% | $3,529,718 | -$48,258,076 | 576,789 | -93% | T. Rowe Price Associates, Inc. | 30 Sep 2025 |
| SymBiosis Capital Partners, LLC | 6.3% | $2,582,018 | 421,926 | SymBiosis Capital Partners, LLC | 30 Sep 2025 | |||
| RENAISSANCE TECHNOLOGIES LLC | 4.3% | -17% | $1,576,125 | -$310,437 | 287,614 | -16% | Renaissance Technologies LLC | 31 Dec 2025 |
As of 31 Dec 2025, 23 institutional investors reported holding 3,141,316 shares of Generation Bio Co. - Common Stock, $0.0001 Par Value (GBIO). This represents 47% of the company’s total 6,735,691 outstanding shares.
The largest institutional shareholders of Generation Bio Co. - Common Stock, $0.0001 Par Value (GBIO) together control 47% 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 |
|---|---|---|---|---|---|
| Atlas Venture Life Science Advisors, LLC | 12% | 827,946 | 0.54% | $4,702,732 | |
| SymBiosis Capital Partners, LLC | 9.9% | 665,000 | 0% | 3.9% | $3,777,200 |
| RENAISSANCE TECHNOLOGIES LLC | 4.3% | 287,614 | -16% | 0% | $1,633,648 |
| VANGUARD GROUP INC | 3.4% | 229,833 | 0% | 0% | $1,305,451 |
| Siren, L.L.C. | 3% | 201,419 | -32% | 0.03% | $1,144,060 |
| UBS Group AG | 2.4% | 164,716 | +11% | 0% | $935,587 |
| MORGAN STANLEY | 2.4% | 161,378 | -1.8% | 0% | $916,627 |
| MARSHALL WACE, LLP | 2.1% | 140,294 | -36% | 0% | $796,870 |
| ACADIAN ASSET MANAGEMENT LLC | 1.8% | 121,029 | -5.1% | 0% | $686,000 |
| GOLDMAN SACHS GROUP INC | 1.4% | 91,527 | -23% | 0% | $519,873 |
| BlackRock, Inc. | 0.89% | 60,070 | -0.08% | 0% | $341,197 |
| GEODE CAPITAL MANAGEMENT, LLC | 0.77% | 51,795 | +4% | 0% | $294,268 |
| DRW Securities, LLC | 0.65% | 43,812 | 0.02% | $248,852 | |
| DELTEC ASSET MANAGEMENT LLC | 0.48% | 32,650 | 0.03% | $185,452 | |
| TD Asset Management Inc | 0.4% | 26,708 | 0% | 0% | $151,701 |
| STATE STREET CORP | 0.3% | 19,993 | 0% | 0% | $113,560 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE | 0.21% | 14,398 | 0% | 0% | $80,485 |
| JPMORGAN CHASE & CO | 0.01% | 689 | +0.29% | 0% | $3,914 |
| Sterling Capital Management LLC | 0% | 194 | 0% | 0% | $1,102 |
| BNP PARIBAS FINANCIAL MARKETS | 0% | 147 | 0% | 0% | $835 |
| SBI Securities Co., Ltd. | 0% | 53 | 0% | 0% | $301 |
| WELLS FARGO & COMPANY/MN | 0% | 50 | 0% | 0% | $284 |
| Smartleaf Asset Management LLC | 0% | 1 | 0% | $6 | |
| CITIGROUP INC | 0% | 0 | -100% | $0 |