X0508 4 2026-02-24 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001596796 Rutten Guillaume Marie Jean 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 0 0 0 0 Common Stock 2026-02-24 4 M 0 10748 0 A 563866 D Common Stock 2026-02-24 4 S 0 20000 48.80 D 543866 D Restricted Stock Units 0 2026-02-24 4 M 0 10748 0 D Common Stock 10748 0 D The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $48.80 to $48.86. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, Amkor Technology, Inc. (the "Issuer"), or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (1) to this Form 4. Represents shares of the Issuer's common stock underlying time-vested restricted stock units ("RSUs") on February 24, 2022 (the "Grant Date") pursuant to the Issuer's Equity Incentive Plan. The RSUs were awarded for no consideration other than the Reporting Person's service as a service provider of the Issuer and vested in four equal annual installments beginning on the first anniversary of the Grant Date. /s/ Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten 2026-02-26