Form 4 Filing Summary for Susan Y. Kim

Susan Y. Kim, a director and 10% owner of Amkor Technology, Inc. (AMKR), reported transactions on December 19, 2025, and December 23, 2025. On December 19, 2025, 3,244,594 shares were distributed to the 2025 Grantor Retained Annuity Trust No. 1 of James J. Kim, and 2,538,000 shares were distributed to the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim. These transactions were made at a price of $0.0 per share, with post-transaction holdings of 3,244,594 and 2,538,000 shares respectively. Additionally, on December 23, 2025, there was a transaction involving Restricted Stock Units (RSUs) where 20.0093 shares were acquired, resulting in a post-transaction holding of 9874.901 shares. Ms. Kim is the sole trustee for both of these trusts. The filing also details various indirect ownerships through trusts, partnerships, and limited liability companies, with a total post-transaction holding of 6,090,494 directly owned shares. Ms. Kim disclaims beneficial ownership except to the extent of her pecuniary interest.