Bruce C. Cozadd - 09 May 2023 Form 4 Insider Report for ACELYRIN, Inc. (SLRN)

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	SLRN	Director Stock Option (right to buy)	Other	$0	-183,434	-100%	$0.000000^*	0	09 May 2023	Class A Common Stock	183,434	$4.04	Direct	F1, F2
transaction	SLRN	Director Stock Option (right to buy)	Other	$0	+183,434		$0.000000	183,434	09 May 2023	Common Stock	183,434	$4.04	Direct	F1, F2
transaction	SLRN	Director Stock Option (right to buy)	Other	$0	-23,243	-100%	$0.000000^*	0	09 May 2023	Class A Common Stock	23,243	$18.00	Direct	F1, F3
transaction	SLRN	Director Stock Option (right to buy)	Other	$0	+23,243		$0.000000	23,243	09 May 2023	Common Stock	23,243	$18.00	Direct	F1, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Id	Content
F1	Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the Issuer's initial public offering of Common Stock.
F2	1/48 of the shares subject to the option vested on April 7, 2022, and 1/48 of the shares subject to the option vests in equal monthly installments thereafter, subject to the Reporting Person's continued service.
F3	1/36 of the shares subject to the option vest on June 4, 2023, and 1/36 of the shares subject to the option vest in equal monthly installments thereafter, subject to the Reporting Person's continued service.