X0508 4 2026-01-15 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001596796 Rutten Guillaume Marie Jean 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 0 0 0 1 Common Stock 2026-01-15 4 S 0 10000 53.14 D 335391 D The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 06, 2025. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $52.25 to $54.00. 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 (2) to this Form 4. /s/ Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten 2026-01-20