GENERATION BIO CO
COM NEW · CUSIP 37148K209
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable.
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q2 2025 | 4 |
| Q3 2025 | 36 |
| Q4 2025 | 46 |
| Q1 2026 | 0 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2025 | 35 | 3 |
| Q4 2025 | 19 | 18 |
| Q1 2026 | 0 | 44 |
Biggest buyers
| None |
Biggest sellers
| Atlas Venture Life Science Advisors, LLC | Sold out | -827.9k |
| SymBiosis Capital Partners, LLC | Sold out | -665.0k |
| Opaleye Management Inc. | Sold out | -310.0k |
| RENAISSANCE TECHNOLOGIES LLC | Sold out | -287.6k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Sold out | -209.6k |
| Siren, L.L.C. | Sold out | -201.4k |
| UBS Group AG | Sold out | -164.7k |
| MORGAN STANLEY | Sold out | -161.4k |
| MARSHALL WACE, LLP | Sold out | -140.3k |
| ACADIAN ASSET MANAGEMENT LLC | Sold out | -121.0k |
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| SymBiosis Capital Partners, LLC 13G · institution no change · filed 2025-11-14 | 6.3% |
Fell to 5% or below in the last year: PRICE T ROWE ASSOCIATES INC /MD/ (3.1%, 2026-02-17), RENAISSANCE TECHNOLOGIES LLC (4.3%, 2026-02-12), Baselake Partners, LP (0.0%, 2026-02-11)
Holders, Q1 2026
| Manager | Shares | Change |
|---|