Christopher Heery - 13 Jan 2026 Form 4 Insider Report for Arcellx, Inc. (ACLX)

Role: CHIEF MEDICAL OFFICER
Signature: /s/ Michelle Gilson, as Attorney-in-Fact
Issuer symbol: ACLX
Transactions as of: 13 Jan 2026
Net transactions value: -$487,213
Form type: 4
Filing time: 13 Jan 2026, 21:20:02 UTC
Previous filing: 12 Jan 2026
Next filing: 14 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Heery Christopher	CHIEF MEDICAL OFFICER	C/O ARCELLX, INC., 800 BRIDGE PARKWAY, REDWOOD CITY	/s/ Michelle Gilson, as Attorney-in-Fact	13 Jan 2026	0001789632

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ACLX	Common Stock	Options Exercise	$0	+16,520	+121%	$0.000000	30,135	03 Jan 2026	Direct	F1
transaction	ACLX	Common Stock	Sale	$487,213	-7,437	-20%	$65.51	29,631	13 Jan 2026	Direct	F2, 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 ("RSU") represents a contingent right to receive one share of the Issuer's Common Stock. Vesting of these RSUs previously reported in the Form 4 filed January 6, 2026.
F2	Represents a broker-assisted sale to satisfy the Reporting Person's tax withholding obligations in connection with the vesting of restricted stock units.
F3	The price reported reflects the weighted average sales price. These shares were sold in multiple transactions at prices that were not available from the broker at the time of filing. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.