Generation Bio Co. - GBIO
Detailed investor-level table based on 13F positions.
Methodology:
Market value and % of portfolio use SEC reported VALUE ($000).
For PUT/CALL positions this reflects reported underlying exposure, not premium cash paid/received.
Details.
Rows: 0
| Investor | History | Status | Shares held | Market value ($000) | % of portfolio | Previous % | Rank | Change in shares | % change in shares | Source | Date reported |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Atlas Venture Life Science Advisors, LLC | History | No change | 827,946 | 4,702 | 0.54% | 0.67% | 1 | 0 | 0.0% | Q4 2025 | Feb 13, 2026 |
| SymBiosis Capital Partners, LLC | History | New | 665,000 | 3,777 | 3.45% | — | 2 | +665,000 | New | Q4 2025 | Feb 12, 2026 |
| Opaleye Management Inc. | History | New | 310,000 | 1,760 | 0.23% | — | 3 | +310,000 | New | Q4 2025 | Apr 13, 2026 |
| RENAISSANCE TECHNOLOGIES LLC | History | Reduced | 287,614 | 1,633 | 0.0% | 0.0% | 4 | -56,649 | -16.46% | Q4 2025 | Feb 12, 2026 |
| VANGUARD GROUP INC | History | No change | 229,833 | 1,305 | 0.0% | 0.0% | 5 | 0 | 0.0% | Q4 2025 | Jan 29, 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ | History | Reduced | 209,641 | 1,191 | 0.0% | 0.0% | 6 | -367,148 | -63.65% | Q4 2025 | Feb 17, 2026 |
| Siren, L.L.C. | History | Reduced | 201,419 | 1,144 | 0.03% | 0.07% | 7 | -95,473 | -32.16% | Q4 2025 | Feb 13, 2026 |
| UBS Group AG | History | Added to | 164,716 | 935 | 0.0% | 0.0% | 8 | +15,995 | 10.76% | Q4 2025 | Jan 29, 2026 |
| MORGAN STANLEY | History | Reduced | 161,378 | 916 | 0.0% | 0.0% | 9 | -2,892 | -1.76% | Q4 2025 | Feb 13, 2026 |
| MARSHALL WACE, LLP | History | Reduced | 140,294 | 796 | 0.0% | 0.0% | 10 | -78,167 | -35.78% | Q4 2025 | Feb 13, 2026 |
| ACADIAN ASSET MANAGEMENT LLC | History | Reduced | 121,029 | 686 | 0.0% | 0.0% | 11 | -6,477 | -5.08% | Q4 2025 | Feb 10, 2026 |
| Yiheng Capital Management, L.P. | History | No change | 105,524 | 599 | 0.12% | 0.1% | 12 | 0 | 0.0% | Q4 2025 | Feb 17, 2026 |
| Rangeley Capital, LLC | History | New | 98,280 | 558 | 0.46% | — | 13 | +98,280 | New | Q4 2025 | Feb 17, 2026 |
| GOLDMAN SACHS GROUP INC | History | Reduced | 91,527 | 519 | 0.0% | 0.0% | 14 | -27,056 | -22.82% | Q4 2025 | Mar 25, 2026 |
| MILLENNIUM MANAGEMENT LLC | History | Reduced | 88,563 | 503 | 0.0% | 0.0% | 15 | -8,791 | -9.03% | Q4 2025 | Feb 17, 2026 |
| BANK OF AMERICA CORP /DE/ | History | Added to | 84,842 | 481 | 0.0% | 0.0% | 16 | +25 | 0.03% | Q4 2025 | Feb 17, 2026 |
| BlackRock, Inc. | History | Reduced | 60,070 | 341 | 0.0% | 0.0% | 17 | -46 | -0.08% | Q4 2025 | Feb 12, 2026 |
| GEODE CAPITAL MANAGEMENT, LLC | History | Added to | 51,795 | 294 | 0.0% | 0.0% | 18 | +1,990 | 4.0% | Q4 2025 | Feb 09, 2026 |
| TWO SIGMA INVESTMENTS, LP | History | Added to | 50,557 | 287 | 0.0% | 0.0% | 19 | +38,115 | 306.34% | Q4 2025 | Feb 17, 2026 |
| CITADEL ADVISORS LLC | History | Added to | 47,245 | 268 | 0.0% | 0.0% | 20 | +48 | 0.1% | Q4 2025 | Feb 17, 2026 |
| DRW Securities, LLC | History | New | 43,812 | 248 | 0.01% | — | 21 | +43,812 | New | Q4 2025 | Feb 12, 2026 |
| DELTEC ASSET MANAGEMENT LLC | History | New | 32,650 | 185 | 0.03% | — | 22 | +32,650 | New | Q4 2025 | Jan 29, 2026 |
| TD ASSET MANAGEMENT INC | History | No change | 26,708 | 151 | 0.0% | 0.0% | 23 | 0 | 0.0% | Q4 2025 | Feb 10, 2026 |
| Lynx1 Capital Management LP | History | New | 25,000 | 142 | 0.03% | — | 24 | +25,000 | New | Q4 2025 | Feb 17, 2026 |
| TORNO CAPITAL, LLC | History | New | 25,000 | 142 | 0.03% | — | 25 | +25,000 | New | Q4 2025 | Feb 17, 2026 |
| ADAR1 Capital Management, LLC | History | No change | 22,144 | 125 | 0.01% | 0.01% | 26 | 0 | 0.0% | Q4 2025 | Feb 18, 2026 |
| STATE STREET CORP | History | No change | 19,993 | 113 | 0.0% | 0.0% | 27 | 0 | 0.0% | Q4 2025 | Feb 13, 2026 |
| Shay Capital LLC | History | Added to | 19,839 | 112 | 0.01% | 0.01% | 28 | +9,425 | 90.5% | Q4 2025 | Feb 17, 2026 |
| CSS LLC/IL | History | New | 17,464 | 99 | 0.0% | — | 29 | +17,464 | New | Q4 2025 | Feb 17, 2026 |
| NORTHERN TRUST CORP | History | Added to | 17,058 | 96 | 0.0% | 0.0% | 30 | +3,752 | 28.2% | Q4 2025 | Feb 17, 2026 |
| Palo Alto Investors LP | History | No change | 15,047 | 85 | 0.01% | 0.02% | 31 | 0 | 0.0% | Q4 2025 | Feb 17, 2026 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE | History | New | 14,398 | 80 | 0.0% | — | 32 | +14,398 | New | Q4 2025 | Feb 13, 2026 |
| XTX Topco Ltd | History | Added to | 13,122 | 74 | 0.0% | 0.0% | 33 | +1,778 | 15.67% | Q4 2025 | Feb 17, 2026 |
| TWO SIGMA ADVISERS, LP | History | New | 11,930 | 67 | 0.0% | — | 34 | +11,930 | New | Q4 2025 | Feb 17, 2026 |
| Seven Fleet Capital Management LP | History | New | 5,376 | 30 | 0.02% | — | 35 | +5,376 | New | Q4 2025 | Apr 02, 2026 |
| Accent Capital Management, LLC | History | Reduced | 26 | 16 | 0.01% | 0.01% | 36 | -12 | -31.58% | Q4 2025 | Feb 09, 2026 |
| FMR LLC | History | Reduced | 2,617 | 14 | 0.0% | 0.0% | 37 | -10,414 | -79.92% | Q4 2025 | Feb 17, 2026 |
| ROYAL BANK OF CANADA | History | New | 992 | 6 | 0.0% | — | 38 | +992 | New | Q4 2025 | Feb 17, 2026 |
| JPMORGAN CHASE & CO | History | Added to | 689 | 3 | 0.0% | 0.0% | 39 | +2 | 0.29% | Q4 2025 | Feb 11, 2026 |
| Rockefeller Capital Management L.P. | History | Added to | 500 | 2 | 0.0% | 0.0% | 40 | +150 | 42.86% | Q4 2025 | Mar 16, 2026 |
| Sterling Capital Management LLC | History | No change | 194 | 1 | 0.0% | 0.0% | 41 | 0 | 0.0% | Q4 2025 | Feb 13, 2026 |
| BAKER BROS. ADVISORS LP | History | Closed out | 0 | 0 | — | 0.01% | — | -194,493 | -100.0% | Q3 2025 | Nov 14, 2025 |
| CANTOR FITZGERALD, L. P. | History | Closed out | 0 | 0 | — | 0.01% | — | -99,000 | -100.0% | Q3 2025 | Feb 17, 2026 |
| OSAIC HOLDINGS, INC. | History | Closed out | 0 | 0 | — | 0.0% | — | -15,459 | -100.0% | Q3 2025 | Nov 14, 2025 |
| CITIGROUP INC | History | Closed out | 0 | 0 | — | 0.0% | — | -668 | -100.0% | Q3 2025 | Nov 10, 2025 |
| BNP PARIBAS FINANCIAL MARKETS | History | Reduced | 147 | 0 | — | — | — | -7 | -4.55% | Q4 2025 | Feb 10, 2026 |
| CWM, LLC | History | Reduced | 1 | 0 | — | — | — | -7 | -87.5% | Q4 2025 | Jan 26, 2026 |
| Optiver Holding B.V. | History | Reduced | 2 | 0 | — | — | — | -3 | -60.0% | Q4 2025 | Feb 17, 2026 |
| Smartleaf Asset Management LLC | History | New | 1 | 0 | — | — | — | +1 | New | Q4 2025 | Feb 13, 2026 |
| HUNTINGTON NATIONAL BANK | History | No change | 1 | 0 | — | — | — | 0 | 0.0% | Q4 2025 | Feb 09, 2026 |
| WELLS FARGO & COMPANY/MN | History | No change | 50 | 0 | — | — | — | 0 | 0.0% | Q4 2025 | Feb 13, 2026 |
| SBI Securities Co., Ltd. | History | No change | 53 | 0 | — | — | — | 0 | 0.0% | Q4 2025 | Feb 03, 2026 |