X0306 4 2021-09-20 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001881182 Dylan Investments, LLC C/O SIANA CARR O'CONNOR & LYNAM, 1500 EAST LANCASTER AVENUE PAOLI PA 19301-9713 0 0 0 1 Member of 10% owner group (2) Common Stock 2021-09-20 5 J 0 E 2733334 A 2733334 D On September 20, 2021, the Susan Y. Kim Irrevocable Trust Dated 4/16/98 fbo Dylan James Panichello transferred 2,733,334 shares of the Issuer's Common Stock to the reporting person in exchange for 100% of the latter's Units. Susan Y. Kim and John T. Kim are the co-trustees of the trust. Susan Y. Kim and Liam E. Blaney are the managers 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/ Richard D. Rosen, Attorney-in-Fact 2022-01-20