Arcellx (ACLX) CFO gifts 5,000 shares to family foundation

Rhea-AI Filing Summary

Arcellx, Inc.’s Chief Financial Officer, Michelle Gilson, reported a bona fide gift of 5,000 shares of Common Stock. On March 17, 2026, she transferred these shares for no consideration to a family charitable foundation.

After the gift, she directly owns 28,938 shares of Arcellx common stock and the foundation holds 5,000 shares indirectly attributed to her. She serves as President of the foundation and retains voting and investment power over all securities owned by it, so her overall economic exposure remains largely intact despite this non-market transfer.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a 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). See Instruction 10.

1. Name and Address of Reporting Person^*

Gilson Michelle

(Last) (First) (Middle)

C/O ARCELLX, INC.

800 BRIDGE PARKWAY

(Street)

REDWOOD CITY CALIFORNIA 94065

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Arcellx, Inc. [ ACLX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF FINANCIAL OFFICER

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/17/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/17/2026		G		5,000	D	$0	28,938	D(1)
Common stock								5,000	I(1)	By Foundation

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. On March 17, 2026, the Reporting Person transferred, for no consideration, 5,000 shares to a family charitable foundation of which the Reporting Person serves as the President. The Reporting Person has voting and investment power over all securities owned by the foundation.

	/s/ Michelle Gilson	03/19/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Arcellx (ACLX) disclose for CFO Michelle Gilson?

Arcellx reported that CFO Michelle Gilson made a bona fide gift of 5,000 shares of Common Stock. The shares were transferred for no consideration to a family charitable foundation on March 17, 2026, and represent a non-market disposition rather than an open-market sale.

How many Arcellx (ACLX) shares does the CFO hold after the reported gift?

Following the gift transaction, CFO Michelle Gilson directly holds 28,938 Arcellx Common Stock shares. In addition, a family charitable foundation associated with her holds 5,000 shares indirectly, giving her continued voting and investment power over those foundation-owned securities.

Who received the 5,000 gifted Arcellx (ACLX) shares from the CFO?

The 5,000 Arcellx shares were transferred to a family charitable foundation of which CFO Michelle Gilson serves as President. The transfer was for no consideration, and she retains voting and investment power over all securities owned by the foundation after the gift.

Does the Arcellx (ACLX) CFO retain control over the shares gifted to the foundation?

Yes. Although the 5,000 shares were gifted to a family charitable foundation, Michelle Gilson remains President of the foundation. She continues to have voting and investment power over all securities the foundation owns, including the transferred Arcellx shares, according to the disclosure footnote.

Was the Arcellx (ACLX) CFO’s 5,000-share transfer an open-market sale?

No. The transaction is classified as a bona fide gift, not an open-market sale. The 5,000 Arcellx shares were transferred for no consideration to a family charitable foundation, meaning no sale proceeds were received and the move reflects charitable giving rather than trading activity.

How does the Arcellx (ACLX) Form 4 classify the CFO’s 5,000-share transaction?

The Form 4 uses transaction code G, identifying the event as a bona fide gift. It records 5,000 shares of Arcellx Common Stock disposed of by gift, with total direct holdings after the transaction of 28,938 shares and an additional 5,000 shares held indirectly by the foundation.