X0609 4 2026-03-31 0001851961 GCT Semiconductor Holding, Inc. GCTS 0001242653 Chan Nelson false C/O GCT SEMICONDUCTOR HOLDING, INC. 2290 NORTH 1ST STREET, SUITE 201 SAN JOSE CA 95131 true true Class I Director false Common Stock 2026-03-31 4 A 0 24122 0 A 125642 D Represents Restricted Stock Units ("RSUs") acquired pursuant to the terms of the GCT Semiconductor Holding, Inc. (the "Issuer") GCT 2024 Omnibus Incentive Compensation Plan. Each RSU represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of the Issuer following vesting. The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2025 through March 31, 2026 (beginning with the quarter ending June 30, 2025) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $1.14 on March 31, 2026, rounded down to the nearest whole share. The RSUs will vest on March 31, 2026, subject to continued service through such date. No expiration date is applicable to restricted stock units. /s/ Edmond Cheng, attorney-in-fact 2026-04-02