Arcellx, Inc. — Director's Dealing 2024

Jul 3, 2024

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Arcellx, Inc. (ACLX)
CIK: 0001786205
Period of Report: 2024-07-01

Reporting Person: Heery Christopher (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2024-07-01	Common Stock	M	7036	$6.28	Acquired	16314	Direct
2024-07-01	Common Stock	M	12964	$15	Acquired	29278	Direct
2024-07-01	Common Stock	S	17217	$55.2577	Disposed	12061	Direct
2024-07-01	Common Stock	S	2783	$56.195	Disposed	9278	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2024-07-01	Stock Option (right to buy)	$6.28	M	7036	Disposed	2031-06-09	Common Stock (7036)	Direct
2024-07-01	Stock Option (right to buy)	$15	M	12964	Disposed	2032-02-03	Common Stock (12964)	Direct

Footnotes

F1: The sale of shares reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan entered into by the Reporting Person on December 22, 2023.

F2: Represents the weighted average share price of an aggregate total of 17,217 shares sold in the price range of $55.03 to $56.00 by the Reporting Person. The Reporting Person undertakes to provide upon request by the Commission staff, the issuer or a security holder of
the issuer, full information regarding the number of shares sold at each separate price.

F3: Represents the weighted average share price of an aggregate total of 2,783 shares sold in the price range of $56.06 to $56.47 by the Reporting Person. The Reporting Person undertakes to provide upon request by the Commission staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

F4: Shares issued pursuant to the Issuer's 2017 Equity Incentive Plan (the "2017 Plan"). Subject to the Reporting Person continuing to be a Service Provider (as defined in the 2017 Plan) through each applicable date, twenty-five percent (25%) of the shares subject to the
option shall vest on the one (1) year anniversary of the Vesting Commencement Date, and one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter on the same day of the month as the Vesting Commencement Date (and if there is no
corresponding day, on the last day of the month). "Vesting Commencement Date" shall mean April 26, 2021.

F5: Subject to the Reporting Person continuing to be a Service Provider (as defined in the Issuer's 2022 Equity Incentive Plan) through each applicable vesting date, one forty-eighth (1/48th) of the shares subject to the option will vest each month following the Equity Grant Date on the same day of the month as the Equity Grant Date (or, if there is no corresponding day in a particular month, then the last day of the month) over four (4) years. "Equity Grant Date" shall mean February 3, 2022.