Generation Bio Co.
GBIODelisted Feb 9, 2026- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001733294
Generation Bio Co. was delisted on Feb 9, 2026; its insiders filed their last Form 4 on Feb 9, 2026; 48 institutions reported holding it in 13F filings for Q4 2025, worth $24.5M in total; no superinvestor held it.
Key figures
- Insider buys
- 0
- Open market, last 90 days
- Insider sells
- 0
- Open market, last 90 days
- 13F holders
- 48
- Q4 2025, +7 vs. previous quarter
- 13F value
- $24.5M
- Reported value at the end of Q4 2025
- Superinvestors holding
- 0
- At the end of Q4 2025
Superinvestors holding GBIO, Q4 2025
No superinvestor reported holding GBIO at the end of Q4 2025.
Latest insider trades
Open-market purchases and sales by Generation Bio Co. insiders from Form 4, newest first.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Jan 14, 2025 (view filing) | Jan 10-13 | 4 days | Quinn Anthony G.Director | PPurchase | +210.8K | $0.964 | +$203.2K | +238.2%299.3K after | 2 lots |
| Jul 3, 2024 (view filing) | Jul 1 | 2 days | Paone AntoinetteCHIEF OPERATING OFFICER | SSale | −6.72K | $2.74 | −$18.4K | −32.7%13.8K after | |
| Jan 3, 2024 (view filing) | Jan 2 | 1 day | Samayoa PhillipCHIEF STRATEGY OFFICER | SSale | −2.44K | $1.62 | −$3.96K | −2.2%107.3K after | 10b5-1 |
| Jan 3, 2024 (view filing) | Jan 2 | 1 day | Paone AntoinetteCHIEF OPERATING OFFICER | SSale | −2.44K | $1.62 | −$3.96K | −29.6%5.83K after | 10b5-1 |
| Dec 11, 2023 (view filing) | Dec 8 | 3 days | Appelhans DannielleDirector | PPurchase | +637 | $1.82 | +$1.16K | +5.3%12.6K after | |
| Dec 11, 2023 (view filing) | Dec 8 | 3 days | Appelhans DannielleDirector | PPurchase | +7.36K | $1.79 | +$13.2K | New position7.36K after | |
| Dec 6, 2023 (view filing) | Dec 4 | 2 days | Appelhans DannielleDirector | PPurchase | +12.0K | $1.50 | +$18.0K | New position12.0K after | |
| Dec 5, 2023 (view filing) | Dec 1-4 | 4 days | Rowland Charles A JrDirector | PPurchase | +343.0K | $1.39 | +$477.8K | +178.8%534.8K after | 2 lots |
| Dec 5, 2023 (view filing) | Dec 1 | 4 days | Quinn Anthony G.Director | PPurchase | +88.5K | $1.41 | +$124.8K | New position88.5K after | |
| Dec 5, 2023 (view filing) | Dec 1 | 4 days | Nicholson Donald WilliamDirector | PPurchase | +100.0K | $1.44 | +$144.0K | +88.0%213.6K after |
Top 10 13F holders, Q4 2025
The largest institutional positions in Generation Bio Co. at the end of Q4 2025; share changes are against Q3 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Atlas Venture Life Science Advisors, LLC | 827,946 | $4.70M | 0.54% | 00.0% | Unchanged |
| SymBiosis Capital Partners, LLC | 665,000 | $3.78M | 3.45% | +665,000 | New |
| Opaleye Management Inc. | 310,000 | $1.76M | 0.23% | +310,000 | New |
| Renaissance Technologies LLC | 287,614 | $1.63M | 0.00% | −56,649−16.5% | Reduced |
| Vanguard Group Inc | 229,833 | $1.31M | 0.00% | 00.0% | Unchanged |
| Price T Rowe Associates Inc | 209,641 | $1.19M | 0.00% | −367,148−63.7% | Reduced |
| Siren, L.L.C. | 201,419 | $1.14M | 0.03% | −95,473−32.2% | Reduced |
| UBS Group AG | 164,716 | $935.6K | 0.00% | +15,995+10.8% | Added |
| Morgan Stanley | 161,378 | $916.6K | 0.00% | −2,892−1.8% | Reduced |
| Marshall Wace, LLP | 140,294 | $796.9K | 0.00% | −78,167−35.8% | Reduced |
Holders of 5% or more of GBIO
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Generation Bio Co..
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| SymBiosis Capital Partners, LLC | 13G/A | 6.30%421.9K shares | 0.00 ppfrom 6.30% | Nov 14, 20252 filings | Nov 14, 2025 | SEC |