X0306 4 2022-02-15 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001596796 Rutten Guillaume Marie Jean 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 1 0 0 President and CEO Common Stock 2022-02-15 4 M 0 10000 14.17 A 315000 D Common Stock 2022-02-15 4 S 0 25000 22.00 D 290000 D Employee Stock Option (Right-to-Buy) 14.17 2022-02-15 4 M 0 10000 0.00 D 2020-10-30 2030-07-30 Common Stock 10000 222500 D The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 13, 2021. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.00 to $22.03.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. This stock option (the "Option") to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 (the "Grant Date") and will vest in equal quarterly installments over three years, such that 100% of the Option will be vested on the third anniversary of the Grant Date. Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten 2022-02-17