Material Agreement (Form 8-K)

On February 24, 2026, GCT Semiconductor, Inc., a subsidiary of GCT Semiconductor Holding, Inc. (the "Company"), entered into Amendment No. 1 (the "Amendment") to that certain Convertible Promissory Note, dated February 26, 2024 (the "Original Note" and, as amended by the Amendment, the "Note") with a strategic investor (the "Holder"). The Amendment modifies certain terms of the Original Note, including the extension of the maturity date of the Note to February 26, 2028. Except as expressly amended by the Amendment, the terms and provisions of the Original Note remain in full force and effect.

In connection with the execution of the Amendment, on February 24, 2026, the Company and the Holder entered into a Warrant Issuance Agreement (the "Warrant Issuance Agreement"), pursuant to which the Company agreed to issue to the Holder a warrant (the "Warrant") to purchase 500,000 shares of the Company's common stock, in consideration of the Holder's agreement to enter into the Amendment. The Warrant has an exercise price of $2.50 per share and a term of three (3) years from the date of issuance.

The foregoing descriptions are qualified in their entirety by reference to the Amendment, the Warrant Issuance Agreement and the Warrant, filed as Exhibits 10.1, 10.2 and 10.3, respectively, and incorporated herein by reference.