Amkor Technology Announces Pricing of Secondary Offering of 10 million Shares of Common Stock by the Kim Family

Amkor Technology, Inc. (Nasdaq: AMKR) (“Amkor” or the “Company”), a leading provider of semiconductor packaging and test services, today announced the pricing of a secondary underwritten public offering of 10,000,000 shares of the Company’s common stock (“Common Stock”) by 915 Investments, LP (the “selling stockholder”) at a public offering price of $24 per share. The selling stockholder is an investment vehicle for members of the family of James J. Kim, the founder and Executive Chairman of the Board of Directors of Amkor (the “Board”), and Susan Y. Kim, the Executive Vice Chairman of the Board. The selling stockholder has granted the underwriters a 30-day option to purchase up to an additional 1,500,000 shares of Common Stock. All of the shares in the offering will be sold by the selling stockholder. The Company will not receive any proceeds from the sale of the shares by the selling stockholder. Members of the Kim family and their affiliates will continue to own a majority of Amkor’s shares following the sale.

The selling stockholder has also entered into a lock-up agreement under which it has agreed that neither the selling stockholder nor any of its direct or indirect affiliates, other than the Company and its subsidiaries, will sell, or otherwise transfer or dispose of, any of its remaining shares of Common Stock for a period of 365 days after the date of the final prospectus, subject to certain exceptions. The Company has entered into a clear market provision pursuant to which it has agreed not to offer or otherwise sell shares of Common Stock for a period of 60 days after the date of the final prospectus, subject to certain exceptions.

J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC are serving as joint lead bookrunning managers and as representatives of the underwriters for the offering. Goldman Sachs & Co. LLC and Guggenheim Securities, LLC are also serving as joint bookrunners for the offering. B. Riley Securities, Inc., D.A. Davidson & Co., KeyBanc Capital Markets Inc. and Needham & Company, LLC are serving as co-managers for the offering.

The Company has filed an effective shelf registration statement including a prospectus and a preliminary prospectus supplement with the Securities and Exchange Commission (“SEC”) for the offering to which this communication relates. Before you invest, you should read the prospectus and preliminary prospectus supplement in that registration statement and other documents the Company has filed with the SEC for more complete information about the Company, the selling stockholder and this offering. You may obtain these documents for free by visiting EDGAR on the SEC’s website at www.sec.gov. Alternatively, the Company, any underwriter or any dealer participating in the offering will arrange to send you the prospectus and the preliminary prospectus supplement if you request them by contacting J.P. Morgan Securities LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at [phone], or by email at [e-mail]; or Morgan Stanley & Co. LLC, Attention: Prospectus Department, 180 Varick Street, 2^nd Floor, New York, NY 10014 or by email at [e-mail].