X0508 4 2023-09-06 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001460579 915 Investments, LP C/O SIANA CARR O'CONNOR & LYNAM 1500 EAST LANCASTER AVENUE PAOLI PA 19301-971 0 0 0 1 Member of 10% owner group (2) 0 Common Stock 2023-09-06 4 S 0 10000000 23.22 D 39594980 D On September 6, 2023, the Reporting Person sold 10,000,000 shares of Common Stock of Amkor Technology, Inc. pursuant to an underwritten secondary offering. James J. Kim is the general partner of the Reporting Person. (2) The Reporting Person states that the filing of this Form 4 shall not be deemed an admission that the Reporting Person is the beneficial owner of the reported securities owned by the other members of the group, for the purpose of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. /s/ Brian D. Short, Attorney-in-Fact for 915 Investments, LP 2023-09-06