X0306 4 2022-11-08 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 2022-11-08 4 M 0 10000 9.48 A 240000 D Common Stock 2022-11-08 4 M 0 20000 14.17 A 260000 D Common Stock 2022-11-08 4 S 0 60000 22.00 D 200000 D Employee Stock Option (Right-to-Buy) 9.48 2022-11-08 4 M 0 10000 0.00 D 2020-02-15 2029-02-15 Common Stock 10000 40625 D Employee Stock Option (Right-to-Buy) 14.17 2022-11-08 4 M 0 20000 0.00 D 2020-10-30 2030-07-30 Common Stock 20000 162500 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 26, 2022. This stock option (the "2019 Option") to acquire 150,000 shares of the Issuer's common stock (the "2019 Option Shares") was granted on February 15, 2019 (the "2019 Grant Date") and vests over four years as follows: (i) with respect to 25% of the 2019 Option Shares, on the first anniversary of the 2019 Grant Date; and (ii) with respect to the remainder of the 2019 Option Shares, in equal quarterly installments thereafter, such that 100% of the 2019 Option will vest on the fourth anniversary of the 2019 Grant Date. This stock option (the "2020 Option") to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 (the "2020 Grant Date") and will vest in equal quarterly installments over three years, such that 100% of the 2020 Option will be vested on the third anniversary of the 2020 Grant Date. Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten 2022-11-10