艾马克技术美股招股说明书(2026-02-13版)

PROSPECTUS SUPPLEMENT 10,000,000 shares Amkor Technology, Inc. Common stock The selling stockholder named in this prospectus supplement, or the “Selling Stockholder”, is offering 10,000,000 shares of our commonstock, par value $0.001 per share (the “Common Stock”), in this offering. We will not receive any proceeds from the sale of shares of CommonStock to be offered by the Selling Stockholder. Our Common Stock is listed on The Nasdaq Global Select Market, or Nasdaq, under the symbol “AMKR.” On February11, 2026, the last saleprice of our Common Stock as reported on Nasdaq was $56.17per share. Investing in our Common Stock involves risks. See “Risk Factors” beginning on pageS-19 of this prospectus supplement and page 2 of theaccompanying prospectus, in our most recent Annual Report on Form 10-K, in our most recent Quarterly Reports on Form 10-Q, and in any ofour other filings with the Securities and Exchange Commission (“SEC”), incorporated by reference herein. Public offering price Underwriting discounts and commissions(2) Proceeds to the Selling Stockholder, before expenses (2)See “Underwriting” in this prospectus supplement for a description of compensation payable to the underwriter. The Selling Stockholder has granted the underwriter the right to purchase up to an additional 1,500,000 shares of Common Stock from the SellingStockholder at the public offering price, less underwriting discounts and commissions, for 30 days after the date of this prospectus supplement. We willnot receive any proceeds from the sale of shares by the Selling Stockholder as a result of the underwriter’s option to purchase additional shares. Delivery of the shares of Common Stock in book-entry form through The Depository Trust Company, or DTC, will be made on or about February17, 2026. Goldman Sachs& Co. LLC Table of Contents You should rely only on the information contained in this prospectus supplement, the accompanying prospectus, any free writingprospectus, and the documents incorporated by reference in this prospectus supplement and the accompanying prospectus. We have not,the Selling Stockholder has not, and the underwriter has not, authorized any other person to provide you with different or additionalinformation. The Selling Stockholder is not, and the underwriter is not, making an offer to sell these securities in any jurisdiction where theoffer or sale is not permitted. This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering and also adds to andupdates information contained in the accompanying prospectus. The second part is the accompanying prospectus, which gives moregeneral information and disclosure about securities we or the Selling Stockholder may offer from time to time, some of which does notapply to the shares of Common Stock offered hereby. To the extent the information contained in this prospectus supplement differs fromthe information contained in the accompanying prospectus, the information in this prospectus supplement shall control. The informationcontained in this prospectus supplement, the accompanying prospectus, and any free writing prospectuses is complete and accurate onlyas of their respective dates. If the information contained in this prospectus supplement differs or varies from the information contained in adocument we have incorporated by reference, you should rely on the information in the more recent document. Any statement made in thisprospectus supplement or in a document incorporated or deemed to be incorporated by reference in this prospectus supplement will bedeemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in thisprospectus supplement or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference inthis prospectus supplement modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, exceptas so modified or superseded, to constitute a part of this prospectus supplement. Our business, financial condition, results of operationsand prospects may have changed since those dates. If there is a material change in our affairs, we will amend or supplement thisprospectus supplement only as required by law. You should not consider any information in this prospectus supplement or the accompanying prospectus to be investment, legal or taxadvice. You should consult your own counsel, accountant and other advisors for legal, tax, business, financial and related advice regardingthe purchase of the common stock. Neither we, the Selling Stockholder nor the underwriter (or any of our or their respective affiliates) aremaking any representation to you regarding the legality of an investment in the Common Stock by you under applicable investment orsimilar laws. Market and industry data Market and industry data throughout this prospectus supplement, the accompanying prosp