Phillip Samayoa - 15 Jan 2025 Form 4 Insider Report for Generation Bio Co. (GBIO)

Role: CHIEF SCIENTIFIC OFFICER
Signature: /s/ Shawna-Gay White, Attorney-in-Fact
Issuer symbol: GBIO
Transactions as of: 15 Jan 2025
Net transactions value: -$353
Form type: 4
Filing time: 17 Jan 2025, 16:05:11 UTC
Previous filing: 14 Jan 2025
Next filing: 17 Apr 2025
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	GBIO	Common Stock	Options Exercise		+1,147	+0.9%		128,107	15 Jan 2025	Direct	F1
transaction	GBIO	Common Stock	Tax liability	$353	-398	-0.31%	$0.8880	127,709	15 Jan 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	-1,147	-11%	$0.000000	9,170	15 Jan 2025	Common Stock	1,147		Direct	F1, F2

* 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	On January 20, 2023, the reporting person was granted 18,345 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.