SCHEDULE 13G/A 0001104659-22-022848 0001891676 XXXXXXXX LIVE 1 Common Stock, par value $0.0001 per share 03/26/2025 0001851961 GCT Semiconductor Holding, Inc. 36170N107 2290 North 1st Street, Suite 201 San Jose CA 95131 Rule 13d-1(d) Concord Sponsor Group III LLC DE 632586.00 0.00 632586.00 0.00 632586.00 N 1.31 OO Concord Sponsor Group III LLC (the "Sponsor") holds 632,586 shares of Common Stock. The securities described above are held directly by the Sponsor. The Sponsor is governed by a board of managers consisting of three managers, Bob Diamond, David Schamis and Timothy Kacani. Any action by the Sponsor with respect to the issuer or the issuer's securities held by the Sponsor, including voting and dispositive decisions, requires at least a majority vote of the managers of the board of managers. Under the so-called "rule of three", because voting and dispositive decisions are made by a majority of the managers, none of the managers is deemed to be a beneficial owner of issuer's securities held by the Sponsor, even those in which such manager holds a pecuniary interest. Accordingly, none of the managers on Sponsor's board of managers is deemed to have or share beneficial ownership of the founder shares held by the Sponsor. The aggregate percentage of Common Stock beneficially owned by the Reporting Person is calculated based upon 48,246,480 shares of Common Stock outstanding as of March 20, 2025, as reported by the Issuer in its Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 25, 2025. GCT Semiconductor Holding, Inc. 2290 North 1st Street, Suite 201, San Jose, CA, 95131 Concord Sponsor Group III LLC 477 Madison Avenue, 22nd Floor, New York, NY, 10022 Concord Sponsor Group III LLC is a Delaware limited liability company. Y 632,586 1.31% 632,586 0 632,586 0 N Y Y Y Y Y Y Concord Sponsor Group III LLC /s/ Jason T. Simon 03/28/2025 The Powers of Attorney given by Concord Sponsor Group III LLC was previously filed as exhibits 24.1 to the Form 3 filed by Concord Sponsor Group III LLC with the SEC on November 3, 2021 and is herein incorporated by reference.