Antoinette Paone - Jul 15, 2025 Form 4 Insider Report for Generation Bio Co. (GBIO)

Role
CHIEF OPERATING OFFICER
Signature
/s/ Shawna-Gay White, Attorney-in-Fact
Stock symbol
GBIO
Transactions as of
Jul 15, 2025
Transactions value $
-$199
Form type
4
Date filed
7/17/2025, 04:10 PM
Previous filing
Apr 17, 2025
Next filing
Oct 17, 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Paone Antoinette CHIEF OPERATING OFFICER C/O GENERATION BIO CO., 301 BINNEY ST, CAMBRIDGE /s/ Shawna-Gay White, Attorney-in-Fact 2025-07-17 0001907682

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction GBIO Common Stock Options Exercise +1.59K +4.64% 35.9K Jul 15, 2025 Direct F1, F2
transaction GBIO Common Stock Tax liability -$199 -468 -1.3% $0.43 35.5K Jul 15, 2025 Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction GBIO Restricted Stock Units Options Exercise $0 -1.59K -14.29% $0.00 9.55K Jul 15, 2025 Common Stock 1.59K Direct F1, F3
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Each restricted stock unit represents the right to receive one share of the company's common stock.
F2 Includes 11,259 shares acquired under the company's employee stock purchase plan since April 15, 2025.
F3 On January 20, 2023, the reporting person was granted 25,467 restricted stock units. The shares underlying the restricted stock units vest over four years, with 25% of the shares vested on January 15, 2024 and the remaining shares vesting in equal quarterly installments thereafter.