Rami Elghandour - 27 Feb 2026 Form 4 Insider Report for Arcellx, Inc. (ACLX)

Signature
/s/ Michelle Gilson, as Attorney-in-Fact
Issuer symbol
ACLX
Transactions as of
27 Feb 2026
Net transactions value
-$10,243,267
Form type
4
Filing time
27 Feb 2026, 19:48:11 UTC
Previous filing
13 Feb 2026
Next filing
04 Mar 2026

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Elghandour Rami President, CEO and Chairman of the Board, Director C/O ARCELLX, INC, 800 BRIDGE PARKWAY, REDWOOD CITY /s/ Michelle Gilson, as Attorney-in-Fact 27 Feb 2026 0001613689

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction ACLX Common Stock Options Exercise $0 +55,459 +9% $0.000000 673,378 02 Jan 2026 Direct F1
transaction ACLX Common Stock Options Exercise $0 +53,098 +7.9% $0.000000 726,476 03 Jan 2026 Direct F1
transaction ACLX Common Stock Options Exercise $0 +55,991 +7.7% $0.000000 782,467 06 Jan 2026 Direct F1
transaction ACLX Common Stock Sale $10,243,267 -89,916 -25% $113.92 276,051 27 Feb 2026 Direct F2, F3
holding ACLX Common Stock 198,000 27 Feb 2026 By Trust F4
holding ACLX Common Stock 218,500 27 Feb 2026 By Trust F5
* 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 Represents the weighted average share price of an aggregate total of 89,916 shares sold in the price range of $113.83 to $114.25 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 held by a spousal lifetime access non-grantor trust, of which the Reporting Person's spouse is the beneficiary and for which the Reporting Person may be deemed to have Section 16 beneficial ownership. The Reporting Person disclaims beneficial ownership except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such shares for Section 16 or any other purpose.
F5 Shares held by a spousal lifetime access non-grantor trust of which the Reporting Person is a beneficiary and for which the Reporting Person may be deemed to have Section 16 beneficial ownership. The Reporting Person disclaims beneficial ownership except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such shares for Section 16 or any other purpose.

Remarks:

President, CEO and Chairman of the Board