AMKR

SEC source: 0001628280-26-018335 · wk-form4_1773700670.xml · derivative · entry 1

Buntyn Cherie · CIK 0001936124 · Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 799

Underlying: Common Stock · 799 shares

Expires not disclosed

F1 · derivative.exercise_date: Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units (the "RSUs") granted on March 12, 2026 (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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the Grant Date and annually thereafter, 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 (the "RSUs") granted on March 12, 2026 (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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the Grant Date.

SEC source: 0001628280-26-012277 · wk-form4_1772140164.xml · derivative · entry 3

WATSON DAVID N · CIK 0001276908 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 20,000 shares

Expires 2026-05-04

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.

F2 · derivative.exercise_date: This stock option to acquire 20,000 shares of the Issuer's Common Stock was granted on May 4, 2016 and vested in full on May 2, 2017.

F2 · derivative.expiration_date: This stock option to acquire 20,000 shares of the Issuer's Common Stock was granted on May 4, 2016 and vested in full on May 2, 2017.

SEC source: 0001628280-26-012277 · wk-form4_1772140164.xml · nonDerivative · entry 2

WATSON DAVID N · CIK 0001276908 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 120,757

F1 · kind: Exempt purchase under Section 16b-3. Transaction executed as net exercise executed with Amkor Technology, Inc. (the "Issuer"), in which no shares were purchased or sold in the open market.

SEC source: 0001628280-26-012277 · wk-form4_1772140164.xml · nonDerivative · entry 1

WATSON DAVID N · CIK 0001276908 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 122,980

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: 0001628280-26-012267 · wk-form4_1772140058.xml · nonDerivative · entry 3

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,354

SEC source: 0001628280-26-012302 · wk-form4_1772140658.xml · derivative · entry 4

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 910 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.

F3 · derivative.exercise_price: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F3 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F3 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

SEC source: 0001628280-26-012302 · wk-form4_1772140658.xml · nonDerivative · entry 3

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,953

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $48.73 to $48.81. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, 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: 0001628280-26-012302 · wk-form4_1772140658.xml · nonDerivative · entry 2

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 15,453

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 24, 2022 (the "Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-012302 · wk-form4_1772140658.xml · nonDerivative · entry 1

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 15,825

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: 0001628280-26-012300 · wk-form4_1772140576.xml · derivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

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.

F2 · derivative.exercise_price: 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.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

SEC source: 0001628280-26-012300 · wk-form4_1772140576.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 543,866

F1 · price: 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.

SEC source: 0001628280-26-012300 · wk-form4_1772140576.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 563,866

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: 0001628280-26-012296 · wk-form4_1772140502.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 3,493 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.

F2 · derivative.exercise_price: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F2 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F2 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

SEC source: 0001628280-26-012296 · wk-form4_1772140502.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 129,171

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 24, 2022 (the "Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-012296 · wk-form4_1772140502.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 130,668

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: 0001628280-26-012283 · wk-form4_1772140248.xml · derivative · entry 3

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,880 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.

F2 · derivative.exercise_price: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F2 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F2 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

SEC source: 0001628280-26-012283 · wk-form4_1772140248.xml · nonDerivative · entry 2

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 38,904

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 24, 2022 (the "Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-012283 · wk-form4_1772140248.xml · nonDerivative · entry 1

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 39,710

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: 0001628280-26-012267 · wk-form4_1772140058.xml · derivative · entry 4

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,814 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.

F2 · derivative.exercise_price: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F2 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

F2 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on 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.

SEC source: 0001628280-26-012267 · wk-form4_1772140058.xml · nonDerivative · entry 2

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,978

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 24, 2022 (the "Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-012267 · wk-form4_1772140058.xml · nonDerivative · entry 1

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 24,793

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: 0001628280-26-011088 · wk-form4_1771967518.xml · derivative · entry 6

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,731

Underlying: Common Stock · 10,494 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.

F4 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

F4 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

SEC source: 0001628280-26-011088 · wk-form4_1771967518.xml · derivative · entry 5

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,583

Underlying: Common Stock · 6,359 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.

F3 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

F3 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

SEC source: 0001628280-26-011088 · wk-form4_1771967518.xml · nonDerivative · entry 4

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,915

F2 · kind: The transaction represents shares withheld by the Issuer in connection with the vesting of certain RSUs granted to the Reporting Person on February 20, 2025 (the "2025 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011088 · wk-form4_1771967518.xml · nonDerivative · entry 3

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,201

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: 0001628280-26-011088 · wk-form4_1771967518.xml · nonDerivative · entry 2

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,707

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 20, 2024 (the "2024 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011088 · wk-form4_1771967518.xml · nonDerivative · entry 1

Engel Kevin K. · CIK 0001965254 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,304

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: 0001628280-26-011081 · wk-form4_1771967408.xml · derivative · entry 6

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,218

Underlying: Common Stock · 18,106 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.

F4 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

F4 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

SEC source: 0001628280-26-011081 · wk-form4_1771967408.xml · derivative · entry 5

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,810

Underlying: Common Stock · 16,805 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.

F3 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

F3 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

SEC source: 0001628280-26-011081 · wk-form4_1771967408.xml · nonDerivative · entry 4

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 127,175

F2 · kind: The transaction represents shares withheld by the Issuer in connection with the vesting of certain RSUs granted to the Reporting Person on February 20, 2025 (the "2025 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011081 · wk-form4_1771967408.xml · nonDerivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 134,934

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: 0001628280-26-011081 · wk-form4_1771967408.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 116,828

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 20, 2024 (the "2024 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011081 · wk-form4_1771967408.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 124,029

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: 0001628280-26-011074 · wk-form4_1771967313.xml · derivative · entry 6

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,385

Underlying: Common Stock · 8,690 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.

F4 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

F4 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

SEC source: 0001628280-26-011074 · wk-form4_1771967313.xml · derivative · entry 5

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,424

Underlying: Common Stock · 7,422 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.

F3 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

F3 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

SEC source: 0001628280-26-011074 · wk-form4_1771967313.xml · nonDerivative · entry 4

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 37,830

F2 · kind: The transaction represents shares withheld by the Issuer in connection with the vesting of certain RSUs granted to the Reporting Person on February 20, 2025 (the "2025 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011074 · wk-form4_1771967313.xml · nonDerivative · entry 3

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 41,554

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: 0001628280-26-011074 · wk-form4_1771967313.xml · nonDerivative · entry 2

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,864

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 20, 2024 (the "2024 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011074 · wk-form4_1771967313.xml · nonDerivative · entry 1

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,045

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: 0001628280-26-011069 · wk-form4_1771967252.xml · derivative · entry 4

Rutten Guillaume Marie Jean · CIK 0001596796 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 118,795

Underlying: Common Stock · 59,388 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.

F2 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs granted on February 20, 2025 (the "2025 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 will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

F2 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs granted on February 20, 2025 (the "2025 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 will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

SEC source: 0001628280-26-011069 · wk-form4_1771967252.xml · derivative · entry 3

Rutten Guillaume Marie Jean · CIK 0001596796 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 56,470

Underlying: Common Stock · 112,941 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_date: Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units ("RSUs") granted on February 20, 2024 (the "2024 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 will vest over three years, with 40% of the RSUs vesting on each of the first anniversary and the second anniversary of the 2024 Grant Date, and 20% vesting on the third anniversary of the 2024 Grant Date, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

F1 · derivative.expiration_date: Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units ("RSUs") granted on February 20, 2024 (the "2024 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 will vest over three years, with 40% of the RSUs vesting on each of the first anniversary and the second anniversary of the 2024 Grant Date, and 20% vesting on the third anniversary of the 2024 Grant Date, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

SEC source: 0001628280-26-011069 · wk-form4_1771967252.xml · nonDerivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 553,118

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: 0001628280-26-011069 · wk-form4_1771967252.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 493,730

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: 0001628280-26-011061 · wk-form4_1771967182.xml · derivative · entry 6

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,731

Underlying: Common Stock · 10,468 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.

F4 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

F4 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on the 2025 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date.

SEC source: 0001628280-26-011061 · wk-form4_1771967182.xml · derivative · entry 5

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,424

Underlying: Common Stock · 7,153 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.

F3 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

F3 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested RSUs on the 2024 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 an officer of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2024 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2024 Grant Date.

SEC source: 0001628280-26-011061 · wk-form4_1771967182.xml · nonDerivative · entry 4

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,979

F2 · kind: The transaction represents shares withheld by the Issuer in connection with the vesting of certain RSUs granted to the Reporting Person on February 20, 2025 (the "2025 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011061 · wk-form4_1771967182.xml · nonDerivative · entry 3

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 27,676

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: 0001628280-26-011061 · wk-form4_1771967182.xml · nonDerivative · entry 2

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,208

F1 · kind: The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 20, 2024 (the "2024 Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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: 0001628280-26-011061 · wk-form4_1771967182.xml · nonDerivative · entry 1

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,418

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: 0001628280-26-010234 · wk-form4_1771622508.xml · derivative · entry 5

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,743

Underlying: Common Stock · 26,743 shares

Expires not disclosed

F4 · derivative.exercise_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on February 18, 2026 (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 in three equal annual installments beginning on the first anniversary of the Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the Grant Date.

F4 · derivative.expiration_date: Represents shares of the Issuer's common stock underlying time-vested restricted stock units granted on February 18, 2026 (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 in three equal annual installments beginning on the first anniversary of the Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the Grant Date.