GCT Semiconductor Holding Inc美股招股说明书(2026-03-30版)

$20,000,000 Principal Amount of Convertible Promissory Notes and Common Stock Underlying Convertible Promissory Notes We are offering by this prospectus supplement (i) up to $20,000,000 aggregate principal amount of a series of unsecured, interest-freemandatory convertible promissory notes (the “Convertible Notes”) to Obsidian Global GP LLC (the “Investor”), and (ii) the shares ofcommon stock issuable from time to time upon conversion of the Convertible Notes. On March 25, 2026, we entered into a Convertible Promissory Note Purchase Agreement (the “Purchase Agreement”) with theInvestor pursuant to which the Company may issue and sell, from time to time, to the Investor convertible promissory notes in anaggregate principal amount of up to $20,000,000. The Convertible Notes will be issued from time to time in tranches of up to$500,000 per advance, with each advance funded at a purchase price equal to 96.5% of the principal amount (reflecting a 3.5%original issue discount). The Convertible Notes will bear no interest and will mature 24 months from the date of issuance, at whichtime any outstanding amounts will automatically convert unless earlier converted or redeemed in accordance with their terms. TheConvertible Notes will be convertible, at the option of the holder at any time, into shares of the Company’s common stock at aconversion price equal to 95% of the average volume weighted average price of the Company’s common stock during the three tradingdays immediately preceding the date of the applicable conversion notice, subject to customary beneficial ownership and exchange caplimitations. For a more detailed description of the Purchase Agreement and the Convertible Notes, please see our Annual Report onForm 10-K filed with the SEC on March 25, 2026, which we incorporate herein by reference. We may draw an initial advance of up to $500,000 upon the filing of this prospectus supplement under Rule 424(b)(5) in connectionwith our effective shelf registration statement on Form S-3 (File No. 333-286316), originally filed on April 1, 2025 and declaredeffective on April 9, 2025. Beginning on the eleventh trading day following the closing of the initial advance, we may, from time totime and in our discretion, submit purchase notices to the investor for additional advances of up to $500,000 per advance, subject tothe terms and conditions of the purchase agreement, including limitations on frequency, pricing conditions, and the investor’s right todecline any such request. We are not obligated to request any additional advances, and the timing and amount of any such advanceswill be determined by us in our sole discretion. The Investor may convert the outstanding principal of each Convertible Note at any time prior to maturity at a conversion price equalto 95% of the average volume-weighted average price (“VWAP”) of our common stock during the three trading days immediatelypreceding the date on which the Investor delivers a notice of conversion. Conversion of each Convertible Note will be mandatory atmaturity or upon a Change of Control (as defined in the Convertible Note, unless we have delivered a redemption notice in accordancewith the terms of the Convertible Note. We may redeem all or a portion of any Convertible Note for cash beginning 12 months afterissuance at a premium of 7% of the principal amount if redeemed between 12 months and prior to 18 months from issuance, or 14% ofthe principal amount if redeemed on or after 18 months but prior to maturity. We have agreed to maintain, at all times while any Convertible Notes are outstanding, a reserve of authorized but unissued shares ofcommon stock equal to at least two times the number of shares issuable upon full conversion of all outstanding Convertible Notes. The registration of the issuance of common stock hereunder does not necessarily mean that the Investor will convert any ConvertibleNotes. We will not receive any proceeds from the issuance of shares upon conversion of the Convertible Notes, but we will receiveproceeds from the sale of Convertible Notes issued to the Investor pursuant to the Purchase Agreement. We currently intend to use thenet proceeds from this offering for working capital and general corporate purposes, including repayment of certain outstandingindebtedness. We have agreed to pay certain expenses relating to the registration of such shares with the U.S. Securities and ExchangeCommission. See “Plan of Distribution” in this prospectus supplement. No public market currently exists for the Convertible Notes, and we do not intend to apply to list the Convertible Notes on anysecurities exchange or for quotation on any inter-dealer quotation system. Our common stock is listed on The New York StockExchange (the “NYSE”), under the symbol “GCTS.” On March 25, 2026, the closing price of our common stock on the NYSE was$1.30 per share. We are an “emerging growth company” under federal securities laws and are subject to reduced public compa