Kavita Patel - Jun 10, 2025 Form 4 Insider Report for Arcellx, Inc. (ACLX)

Role: Director
Signature: /s/ Michelle Gilson, as Attorney-in-Fact
Stock symbol: ACLX
Transactions as of: Jun 10, 2025
Transactions value $: -$91,050
Form type: 4
Date filed: 6/11/2025, 05:37 PM
Previous filing: May 30, 2025
Next filing: Nov 13, 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Patel Kavita	Director	C/O ARCELLX, INC., 800 BRIDGE PARKWAY, REDWOOD CITY	/s/ Michelle Gilson, as Attorney-in-Fact	2025-06-11	0001670683

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ACLX	Common Stock	Options Exercise	$9.99K	+1.5K		$6.66	1.5K	Jun 10, 2025	Direct
transaction	ACLX	Common Stock	Sale	-$101K	-1.5K	-100%	$67.36	0	Jun 10, 2025	Direct	F1

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	ACLX	Stock Option (right to buy)	Options Exercise	$0	-1.5K	-5.25%	$0.00	27.1K	Jun 10, 2025	Common Stock	1.5K	$6.66	Direct	F2

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

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id	Content
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 March 28, 2024.
F2	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 December 1, 2021.

Content

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 March 28, 2024.

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 December 1, 2021.