Generation Bio Co.

Historical 13F Holders

Symbol
GBIO
CUSIP
37148K100
All holders as of
Q2 2026
Type
Equity
Class
COM
Reported Value, Excluding Options
Total Filings

13D/G Filers

Investors who own more than 5% of a class must file a Schedule 13D or 13G. Each filer's latest filing for 37148K100 since 12/18/2024, largest first.

Filer % of Class Filed
Under 5%, checked the "5 percent or less" box, or amended by a later filing (3)
FMR LLC 13G/A
3.5% 8/6/2025
Event 6/30/2025
BlackRock, Inc. 13G/A 1.7% 7/17/2025
Event 6/30/2025
Atlas Venture Fund X, L.P. 13G/A
0% 5/14/2026
Event 3/31/2026

13F Holders by Quarter

Period Filings Shares, Excl. Options Value, Excl. Options
2026 Q2 1 1.00 $0
2026 Q1 2 62.0 $53.3 k
2025 Q4 2 27.0 $17.0 k
2025 Q3 6 858 k $5.19 M
2025 Q2 63 41.9 M $13.4 M
2025 Q1 84 47.7 M $19.3 M
2024 Q4 83 53.9 M $57.1 M
2024 Q3 79 55.4 M $137 M
2024 Q2 84 56.6 M $160 M
2024 Q1 83 57.1 M $232 M
2023 Q4 81 55.1 M $90.9 M
2023 Q3 80 57.2 M $217 M
2023 Q2 84 57.3 M $315 M
2023 Q1 89 57.4 M $247 M
2022 Q4 104 58.1 M $228 M
2022 Q3 118 57.7 M $306 M
2022 Q2 96 55.4 M $364 M
2022 Q1 91 56.7 M $417 M
2021 Q4 94 55.0 M $391 M
2021 Q3 84 48.0 M $1.20 B
2021 Q2 99 46.5 M $1.25 B
2021 Q1 92 44.6 M $1.27 B
2020 Q4 69 32.0 M $906 M
2020 Q3 55 29.4 M $896 M
2020 Q2 49 28.4 M $581 M