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

Signature
/s/ Shawna-Gay White, Attorney-in-Fact
Issuer symbol
GBIO
Transactions as of
15 Jul 2025
Net transactions value
-$199
Form type
4
Filing time
17 Jul 2025, 16:10:10 UTC
Previous filing
17 Apr 2025
Next filing
17 Oct 2025

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 17 Jul 2025 0001907682

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction GBIO Common Stock Options Exercise +1,592 +4.6% 35,933 15 Jul 2025 Direct F1, F2
transaction GBIO Common Stock Tax liability $199 -468 -1.3% $0.4260 35,465 15 Jul 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 -1,592 -14% $0.000000 9,548 15 Jul 2025 Common Stock 1,592 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.