Rutten Guillaume Marie Jean

SEC source: 0001047127-24-000171 · wk-form4_1724099591.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 224,971

F1 · kind: The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $32.16 to $32.82. 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.

SEC source: 0001047127-24-000171 · wk-form4_1724099591.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 249,971

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000169 · wk-form4_1723754570.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 234,971

F1 · kind: This Form 4 reports the vesting on August 13, 2024 of 106,638 shares of common stock of Amkor Technology, Inc. (the "Issuer") underlying performance-vested restricted stock units ("PSUs") granted to the Reporting Person on December 14, 2023 pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the achievement of either of two internal performance goals related to geographic expansion of the Issuer's manufacturing footprint and expanding the Issuer's advanced packaging capacity in support of end markets with high growth potential.

SEC source: 0001047127-24-000153 · wk-form4_1721248519.xml · derivative · entry 4

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 23,125

Underlying: Common Stock · 15,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_date: This stock option to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 and vested in equal quarterly installments over three years, such that 100% of the option vested on the third anniversary of the grant date.

SEC source: 0001047127-24-000153 · wk-form4_1721248519.xml · nonDerivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 128,333

F1 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $42.49 to $43.47. The Reporting Person hereby undertakes to provide, upon request, to the staff of the SEC, 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 (3) to this Form 4.

SEC source: 0001047127-24-000153 · wk-form4_1721248519.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 151,433

F1 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $42.24 to $42.47. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission (the "SEC"), 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.

SEC source: 0001047127-24-000153 · wk-form4_1721248519.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 153,333

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000151 · wk-form4_1720032958.xml · derivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 43,857 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On December 14, 2023 (the "RSU Grant Date"), the Reporting Person was granted 43,857 time-vested restricted stock units ("RSUs") pursuant to Amkor Technology, Inc.'s (the "Issuer") 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs converted into shares of the Issuer's common stock on a one-to-one basis and vested in full on July 1, 2024.

F1 · derivative.exercise_date: On December 14, 2023 (the "RSU Grant Date"), the Reporting Person was granted 43,857 time-vested restricted stock units ("RSUs") pursuant to Amkor Technology, Inc.'s (the "Issuer") 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs converted into shares of the Issuer's common stock on a one-to-one basis and vested in full on July 1, 2024.

F1 · derivative.expiration_date: On December 14, 2023 (the "RSU Grant Date"), the Reporting Person was granted 43,857 time-vested restricted stock units ("RSUs") pursuant to Amkor Technology, Inc.'s (the "Issuer") 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs converted into shares of the Issuer's common stock on a one-to-one basis and vested in full on July 1, 2024.

SEC source: 0001047127-24-000151 · wk-form4_1720032958.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 138,333

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000131 · wk-form4_1718915733.xml · derivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 38,125

Underlying: Common Stock · 15,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: This stock option to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 and vested in equal quarterly installments over three years, such that 100% of the option vested on the third anniversary of the grant date.

SEC source: 0001047127-24-000131 · wk-form4_1718915733.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 94,476

F1 · kind: The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.59 to $35.00. 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.

SEC source: 0001047127-24-000131 · wk-form4_1718915733.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 119,476

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000124 · wk-form4_1715983384.xml · derivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 53,125

Underlying: Common Stock · 15,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: This stock option to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 and vested in equal quarterly installments over three years, such that 100% of the option vested on the third anniversary of the grant date.

SEC source: 0001047127-24-000124 · wk-form4_1715983384.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 104,476

F1 · kind: The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $33.045 to $33.73. 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.

SEC source: 0001047127-24-000124 · wk-form4_1715983384.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 129,476

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000085 · wk-form4_1713474709.xml · derivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 68,125

Underlying: Common Stock · 15,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: This stock option to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 and vested in equal quarterly installments over three years, such that 100% of the option vested on the third anniversary of the grant date.

SEC source: 0001047127-24-000085 · wk-form4_1713474709.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 114,476

F1 · kind: The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.80 to $31.51. 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.

SEC source: 0001047127-24-000085 · wk-form4_1713474709.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 139,476

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000065 · wk-form4_1710884757.xml · derivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 83,125

Underlying: Common Stock · 15,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: This stock option to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 and vested in equal quarterly installments over three years, such that 100% of the option vested on the third anniversary of the grant date.

SEC source: 0001047127-24-000065 · wk-form4_1710884757.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 124,476

F1 · kind: The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.92 to $31.62. 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.

SEC source: 0001047127-24-000065 · wk-form4_1710884757.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 149,476

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000046 · wk-form4_1708991681.xml · derivative · entry 7

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 21,496

Underlying: Common Stock · 10,748 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F6 · derivative.exercise_price: On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 42,992 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

F6 · derivative.exercise_date: On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 42,992 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

F6 · derivative.expiration_date: On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 42,992 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

SEC source: 0001047127-24-000046 · wk-form4_1708991681.xml · nonDerivative · entry 4

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 134,476

SEC source: 0001047127-24-000046 · wk-form4_1708991681.xml · derivative · entry 6

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 98,125

Underlying: Common Stock · 4,375 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_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 Option Grant Date") and vested in equal quarterly installments over three years, such that 100% of the 2020 Option vested on the third anniversary of the 2020 Option Grant Date.

SEC source: 0001047127-24-000046 · wk-form4_1708991681.xml · derivative · entry 5

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 10,625 shares

Expires 2029-02-15

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · shares: On March 17, 2023, the Reporting Person filed a Form 4 which inadvertently reported that the Reporting Person beneficially owned 15,265 2019 Options Shares (as defined below) as of March 15, 2023, instead of 15,625. As of February 22, 2024, the Reporting Person beneficially owned 0 2019 Option Shares.

F4 · derivative.exercise_date: 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 Option Grant Date") and vested over four years as follows: (i) with respect to 25% of the 2019 Option Shares, on the first anniversary of the 2019 Option 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 vested on the fourth anniversary of the 2019 Option Grant Date.

F3 · derivative.underlying_shares: On March 17, 2023, the Reporting Person filed a Form 4 which inadvertently reported that the Reporting Person beneficially owned 15,265 2019 Options Shares (as defined below) as of March 15, 2023, instead of 15,625. As of February 22, 2024, the Reporting Person beneficially owned 0 2019 Option Shares.

SEC source: 0001047127-24-000046 · wk-form4_1708991681.xml · nonDerivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 123,728

F1 · kind: The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 8, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.40 to $31.00. 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.

SEC source: 0001047127-24-000046 · wk-form4_1708991681.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 148,728

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000046 · wk-form4_1708991681.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 144,353

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-24-000040 · wk-form4_1708641785.xml · derivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 282,352

Underlying: Common Stock · 282,352 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units granted on February 20, 2024 (the "Grant Date") pursuant to the Issuer's Equity Incentive Plan (the "RSUs"). The RSUs were awarded for no consideration other than the Reporting Person's service as an officer of the Issuer and will vest over three years, with 40% of the RSUs vesting on each of the first anniversary and the second anniversary of the Grant Date, and 20% vesting on the third anniversary of the Grant Date,, such that 100% will be vested on the third anniversary of the Grant Date.

F1 · derivative.exercise_date: Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units granted on February 20, 2024 (the "Grant Date") pursuant to the Issuer's Equity Incentive Plan (the "RSUs"). The RSUs were awarded for no consideration other than the Reporting Person's service as an officer of the Issuer and will vest over three years, with 40% of the RSUs vesting on each of the first anniversary and the second anniversary of the Grant Date, and 20% vesting on the third anniversary of the Grant Date,, such that 100% will be vested on the third anniversary of the Grant Date.

F1 · derivative.expiration_date: Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units granted on February 20, 2024 (the "Grant Date") pursuant to the Issuer's Equity Incentive Plan (the "RSUs"). The RSUs were awarded for no consideration other than the Reporting Person's service as an officer of the Issuer and will vest over three years, with 40% of the RSUs vesting on each of the first anniversary and the second anniversary of the Grant Date, and 20% vesting on the third anniversary of the Grant Date,, such that 100% will be vested on the third anniversary of the Grant Date.

SEC source: 0001047127-24-000024 · wk-form4_1708553299.xml · derivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 41,759

Underlying: Common Stock · 13,920 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On the Grant Date, the Reporting Person was granted 55,679 RSUs which vest in four equal annual installments beginning on the first anniversary of the Grant Date.

F1 · derivative.exercise_date: On the Grant Date, the Reporting Person was granted 55,679 RSUs which vest in four equal annual installments beginning on the first anniversary of the Grant Date.

F1 · derivative.expiration_date: On the Grant Date, the Reporting Person was granted 55,679 RSUs which vest in four equal annual installments beginning on the first anniversary of the Grant Date.

SEC source: 0001047127-24-000024 · wk-form4_1708553299.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 133,728

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001047127-23-000049 · wk-form4_1702935962.xml · derivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 43,857

Underlying: Common Stock · 43,857 shares

Expires not disclosed

F1 · derivative.exercise_price: On December 14, 2023 (the "RSU Grant Date"), the Reporting Person was granted 43,857 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in full on July 1, 2024.

F1 · derivative.exercise_date: On December 14, 2023 (the "RSU Grant Date"), the Reporting Person was granted 43,857 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in full on July 1, 2024.

F1 · derivative.expiration_date: On December 14, 2023 (the "RSU Grant Date"), the Reporting Person was granted 43,857 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in full on July 1, 2024.

SEC source: 0001209191-23-024871 · doc4.xml · derivative · entry 5

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 102,500

Underlying: Common Stock · 10,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_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 Option 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 Option Grant Date.

SEC source: 0001209191-23-024871 · doc4.xml · derivative · entry 4

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,265

Underlying: Common Stock · 5,000 shares

Expires 2029-02-15

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: 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 Option Grant Date") and vested over four years as follows: (i) with respect to 25% of the 2019 Option Shares, on the first anniversary of the 2019 Option 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 vested on the fourth anniversary of the 2019 Option Grant Date.

SEC source: 0001209191-23-024871 · doc4.xml · nonDerivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 119,808

F1 · kind: 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.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.53 to $24.11. 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.

SEC source: 0001209191-23-024871 · doc4.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 149,808

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001209191-23-024871 · doc4.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 139,808

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001209191-23-019756 · doc4.xml · derivative · entry 5

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 112,500

Underlying: Common Stock · 10,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_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 Option 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 Option Grant Date.

SEC source: 0001209191-23-019756 · doc4.xml · derivative · entry 4

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,265

Underlying: Common Stock · 5,000 shares

Expires 2029-02-15

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: 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 Option Grant Date") and vested over four years as follows: (i) with respect to 25% of the 2019 Option Shares, on the first anniversary of the 2019 Option 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 vested on the fourth anniversary of the 2019 Option Grant Date.

SEC source: 0001209191-23-019756 · doc4.xml · nonDerivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 134,808

F1 · kind: 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.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $23.99 to $24.71. 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.

SEC source: 0001209191-23-019756 · doc4.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 164,808

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001209191-23-019756 · doc4.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 154,808

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001209191-23-012976 · doc4.xml · derivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 32,244

Underlying: Common Stock · 10,748 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 42,992 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

F1 · derivative.exercise_date: On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 42,992 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

F1 · derivative.expiration_date: On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 42,992 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

SEC source: 0001209191-23-012976 · doc4.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 179,808

F2 · kind: The transaction represents shares withheld by the Issuer in connection with the vesting of certain RSUs granted to the Reporting Person on the RSU Grant Date. These shares were withheld to satisfy the Reporting Person's tax withholding obligations. The Issuer will pay these taxes on behalf of the Reporting Person.

SEC source: 0001209191-23-012976 · doc4.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 180,748

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 42,992 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

SEC source: 0001209191-23-019746 · doc4a.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 149,808

F1 · balance_after: This amendment is being filed to correct the number of shares beneficially owned by the Reporting Person as reported in the original Form 4 filed with the Securities and Exchange Commission on February 24, 2023 (the "Original Form 4"). The Original Form 4 inadvertently overstated the Reporting Person's beneficial ownership in Column 5 of Table I by 30,000 shares.

SEC source: 0001209191-23-019746 · doc4a.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 150,748

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · balance_after: This amendment is being filed to correct the number of shares beneficially owned by the Reporting Person as reported in the original Form 4 filed with the Securities and Exchange Commission on February 24, 2023 (the "Original Form 4"). The Original Form 4 inadvertently overstated the Reporting Person's beneficial ownership in Column 5 of Table I by 30,000 shares.

SEC source: 0001209191-23-010756 · doc4.xml · derivative · entry 6

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 55,679

Underlying: Common Stock · 55,679 shares

Expires not disclosed

F5 · derivative.exercise_price: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on February 16, 2023 (the "RSU Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan (the "RSUs"). The RSUs were awarded for no consideration other than the Reporting Person's service as an officer of the Issuer and will vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

F5 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on February 16, 2023 (the "RSU Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan (the "RSUs"). The RSUs were awarded for no consideration other than the Reporting Person's service as an officer of the Issuer and will vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

F5 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on February 16, 2023 (the "RSU Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan (the "RSUs"). The RSUs were awarded for no consideration other than the Reporting Person's service as an officer of the Issuer and will vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date.

SEC source: 0001209191-23-010756 · doc4.xml · derivative · entry 5

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 122,500

Underlying: Common Stock · 10,000 shares

Expires 2030-07-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_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 Option 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 Option Grant Date.

SEC source: 0001209191-23-010756 · doc4.xml · derivative · entry 4

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,625

Underlying: Common Stock · 5,000 shares

Expires 2029-02-15

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: 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 Option Grant Date") and vested over four years as follows: (i) with respect to 25% of the 2019 Option Shares, on the first anniversary of the 2019 Option 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 vested on the fourth anniversary of the 2019 Option Grant Date.