X0508 4 2025-09-30 0001851961 GCT Semiconductor Holding, Inc. GCTS 0001671976 TUDER JEFFREY C/O GCT SEMICONDUCTOR HOLDING, INC. 2290 NORTH 1ST STREET, SUITE 201 SAN JOSE CA 95131 true true Class III Director false Common Stock 2025-09-30 4 A 0 18092 0 A 94893 D Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of GCT Semiconductor Holding, Inc. (the "Issuer") following vesting. The RSUs become payable in Common Stock in accordance with a deferral election made by the reporting person. 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 $1.52 on September 30, 2025, 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/ Jeffrey Tuder 2025-10-03