144 0001613689 XXXXXXXX LIVE 0001786205 Arcellx, Inc. 001-41259 800 BRIDGE PARKWAY REDWOOD CITY CA 94065 240-327-0603 Elghandour Rami Officer Director Common Stock E-TRADE FINANCIAL CORPORATION

3 EDISON DRIVE ALPHARETTA GA 30005

89916 10243267.39 58479812 02/27/2026 NASDAQ Common Stock 01/02/2026 Restricted Stock Units Issuer N 55459 01/02/2026 N/A Common Stock 01/03/2026 Restricted Stock Units Issuer N 53098 01/03/2026 N/A Common Stock 01/06/2026 Restricted Stock Units Issuer N 55991 01/06/2026 N/A Y SHARES TO BE SOLD TO COVER WITHHOLDING TAXES UPON VESTING OF RESTRICTED STOCK UNIT AWARDS 02/27/2026 /s/ Michelle Gilson, as Attorney-in-Fact