AMKR

SEC source: 0001158922-25-000015 · wk-form4_1764035907.xml · nonDerivative · entry 1

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (10)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,332,494

F1 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of Susan Y. Kim dtd. 8/5/2024 distributed 876,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Reporting Person. The Reporting Person is the sole trustee of the 2024 Grantor Retained Annuity Trust of Susan Y. Kim dtd. 8/5/2024. Because the Reporting Person is the annuitant and sole trustee of the 2024 Grantor Retained Annuity Trust of Susan Y. Kim dtd. 8/5/2024, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001158840-25-000013 · wk-form4_1764035886.xml · nonDerivative · entry 1

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (3)

10b5-1 filing: No plan indicated

Ownership: Indirect · By trusts

Disclosed balance after: 705,000

F1 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024 distributed 705,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Agnes C. Kim Revocable Trust, of which the Reporting Person is the settlor, sole trustee, and sole beneficiary. Susan Y. Kim is the sole trustee of the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024.

SEC source: 0002034102-25-000004 · wk-form4_1764035894.xml · nonDerivative · entry 1

2024 Grantor Retained Annuity Trust of Susan Y. Kim dtd. 8/5/2024 · CIK 0002034102 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,124,000

F1 · shares: On November 20, 2025, the Reporting Person distributed 876,000 shares of the Common Stock of Amkor Technology, Inc. to Susan Y. Kim. Susan Y. Kim is the sole trustee of the Reporting Person. Because Susan. Y. Kim is the annuitant and sole trustee of the Reporting Person, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0002034104-25-000005 · wk-form4_1764035875.xml · nonDerivative · entry 1

2024 Grantor Retained Annuity Trust of Agnes C. Kim dtd. 8/5/2024 · CIK 0002034104 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 895,000

F1 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024 distributed 705,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Agnes C. Kim Revocable Trust, of which Agnes C. Kim is the sole settlor, sole beneficiary, and sole trustee. Susan Y. Kim is the sole trustee of the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024.

SEC source: 0002034103-25-000005 · wk-form4_1764035867.xml · nonDerivative · entry 1

2024 Grantor Retained Annuity Trust of James J. Kim dtd. 8/5/2024 · CIK 0002034103 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,235,000

F1 · shares: On November 20, 2025, the Reporting Person distributed 965,000 shares of the Common Stock of the Amkor Technology, Inc. to the James J. Kim 2018-1 Qualified Annuity Trust U/A dated 8/30/18. James J. Kim and Susan Y. Kim are co-trustees of the trust.

SEC source: 0001628280-25-053216 · wk-form4_1763588332.xml · nonDerivative · entry 1

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

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 346,699

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 June 06, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $31.03 to $32.05. 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: 0001628280-25-053212 · wk-form4_1763588234.xml · derivative · entry 3

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 130,000

Underlying: Common Stock · 20,000 shares

Expires 2029-06-10

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 "Option") to acquire 200,000 shares of the Issuer's common stock (the "Option Shares") was granted on June 10, 2019 (the "Option Grant Date") and vested over four years as follows: (i) with respect to 25% of the Option Shares, on the first anniversary of the Option Grant Date; and (ii) with respect to the remainder of the Option Shares, in equal quarterly installments thereafter, such that 100% of the Option vested on the fourth anniversary of the Option Grant Date.

SEC source: 0001628280-25-053212 · wk-form4_1763588234.xml · nonDerivative · entry 2

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 23,862

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 August 1, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $31.05 to $32.05. 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: 0001628280-25-053212 · wk-form4_1763588234.xml · nonDerivative · entry 1

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 43,862

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: 0001628280-25-052927 · wk-form4_1763501737.xml · derivative · entry 12

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,199

Underlying: Common Stock · 395 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_price: The reported transaction involved the withholding of 395 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F4 · shares: The reported transaction involved the withholding of 395 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F4 · derivative.exercise_date: The reported transaction involved the withholding of 395 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F4 · derivative.expiration_date: The reported transaction involved the withholding of 395 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · derivative · entry 11

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,577

Underlying: Common Stock · 269 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: The reported transaction involved the withholding of 269 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F3 · shares: The reported transaction involved the withholding of 269 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F3 · derivative.exercise_date: The reported transaction involved the withholding of 269 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F3 · derivative.expiration_date: The reported transaction involved the withholding of 269 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · derivative · entry 10

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,644

Underlying: Common Stock · 67 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: The reported transaction involved the withholding of 67 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F2 · shares: The reported transaction involved the withholding of 67 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F2 · derivative.exercise_date: The reported transaction involved the withholding of 67 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F2 · derivative.expiration_date: The reported transaction involved the withholding of 67 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · derivative · entry 9

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,814

Underlying: Common Stock · 66 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: The reported transaction involved the withholding of 66 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

F1 · shares: The reported transaction involved the withholding of 66 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

F1 · derivative.exercise_date: The reported transaction involved the withholding of 66 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

F1 · derivative.expiration_date: The reported transaction involved the withholding of 66 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 8

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,354

F4 · kind: The reported transaction involved the withholding of 395 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 7

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,749

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 · price: The reported transaction involved the withholding of 269 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 6

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,354

F3 · kind: The reported transaction involved the withholding of 269 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 5

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,623

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 · price: The reported transaction involved the withholding of 67 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 4

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,354

F2 · kind: The reported transaction involved the withholding of 67 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 3

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,421

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: The reported transaction involved the withholding of 66 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 2

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,354

F1 · kind: The reported transaction involved the withholding of 66 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052927 · wk-form4_1763501737.xml · nonDerivative · entry 1

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,420

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: 0001628280-25-052924 · wk-form4_1763501633.xml · derivative · entry 12

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,225

Underlying: Common Stock · 369 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_price: The reported transaction involved the withholding of 369 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F4 · shares: The reported transaction involved the withholding of 369 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F4 · derivative.exercise_date: The reported transaction involved the withholding of 369 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F4 · derivative.expiration_date: The reported transaction involved the withholding of 369 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · derivative · entry 11

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 12,942

Underlying: Common Stock · 223 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: The reported transaction involved the withholding of 223 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F3 · shares: The reported transaction involved the withholding of 223 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F3 · derivative.exercise_date: The reported transaction involved the withholding of 223 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F3 · derivative.expiration_date: The reported transaction involved the withholding of 223 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · derivative · entry 10

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,736

Underlying: Common Stock · 47 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: The reported transaction involved the withholding of 47 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F2 · shares: The reported transaction involved the withholding of 47 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F2 · derivative.exercise_date: The reported transaction involved the withholding of 47 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

F2 · derivative.expiration_date: The reported transaction involved the withholding of 47 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · derivative · entry 9

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 910

Underlying: Common Stock · 30 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: The reported transaction involved the withholding of 30 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

F1 · shares: The reported transaction involved the withholding of 30 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

F1 · derivative.exercise_date: The reported transaction involved the withholding of 30 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

F1 · derivative.expiration_date: The reported transaction involved the withholding of 30 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 8

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,321

F4 · kind: The reported transaction involved the withholding of 369 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 7

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,690

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: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 6

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,321

F3 · kind: The reported transaction involved the withholding of 223 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 5

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,544

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: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 4

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,321

F2 · kind: The reported transaction involved the withholding of 47 shares of the Issuer's common stock issuable upon the early vesting of an equal number of RSUs to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 3

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,368

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: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 2

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,321

F1 · kind: The reported transaction involved the withholding of 30 shares of common stock of Amkor Technology, Inc. (the "Issuer") issuable upon the early vesting of an equal number of restricted stock units ("RSUs") to pay taxes associated with the Reporting Person's retirement eligibility status.

SEC source: 0001628280-25-052924 · wk-form4_1763501633.xml · nonDerivative · entry 1

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,351

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: 0001158926-25-000012 · wk-form4_1762471782.xml · nonDerivative · entry 4

KIM JOHN T · CIK 0001158926 · 10% owner · Member of 10% owner group (8)

10b5-1 filing: No plan indicated

Ownership: Indirect · By own GRATs

Disclosed balance after: 1,253,250

F2 · ownership.direct: On November 4, 2025, the John T. Kim 2024 GRAT #2 dtd. 08/09/2024 distributed 40,750 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Reporting Person. The Reporting Person is the sole trustee of the John T. Kim 2024 GRAT #2 dtd. 08/09/2024. Because the Reporting Person is the annuitant and sole trustee of the John T. Kim 2024 GRAT #2 dtd. 08/09/2024, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001158926-25-000012 · wk-form4_1762471782.xml · nonDerivative · entry 3

KIM JOHN T · CIK 0001158926 · 10% owner · Member of 10% owner group (8)

10b5-1 filing: No plan indicated

Ownership: Indirect · By own GRATs

Disclosed balance after: 1,294,000

F1 · ownership.direct: On November 4, 2025, the John T. Kim 2024 GRAT #1 dtd. 08/09/2024 distributed 806,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Reporting Person. The Reporting Person is the sole trustee of the John T. Kim 2024 GRAT #1 dtd. 08/09/2024. Because the Reporting Person is the annuitant and sole trustee of the John T. Kim 2024 GRAT #1 dtd. 08/09/2024, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001158926-25-000012 · wk-form4_1762471782.xml · nonDerivative · entry 2

KIM JOHN T · CIK 0001158926 · 10% owner · Member of 10% owner group (8)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,594,489

F2 · ownership.direct: On November 4, 2025, the John T. Kim 2024 GRAT #2 dtd. 08/09/2024 distributed 40,750 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Reporting Person. The Reporting Person is the sole trustee of the John T. Kim 2024 GRAT #2 dtd. 08/09/2024. Because the Reporting Person is the annuitant and sole trustee of the John T. Kim 2024 GRAT #2 dtd. 08/09/2024, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001158926-25-000012 · wk-form4_1762471782.xml · nonDerivative · entry 1

KIM JOHN T · CIK 0001158926 · 10% owner · Member of 10% owner group (8)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,553,739

F1 · ownership.direct: On November 4, 2025, the John T. Kim 2024 GRAT #1 dtd. 08/09/2024 distributed 806,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Reporting Person. The Reporting Person is the sole trustee of the John T. Kim 2024 GRAT #1 dtd. 08/09/2024. Because the Reporting Person is the annuitant and sole trustee of the John T. Kim 2024 GRAT #1 dtd. 08/09/2024, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0002034100-25-000005 · wk-form4_1762471763.xml · nonDerivative · entry 1

John T. Kim 2024 GRAT #2 dtd. 08/09/2024 · CIK 0002034100 · Member of 10% owner group

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 59,250

F1 · balance_after: On November 4, 2025, the Reporting Person distributed 40,750 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to John T. Kim. John T. Kim is the sole trustee of the Reporting Person. Because John. T. Kim is the annuitant and sole trustee of the Reporting Person, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0002034170-25-000003 · wk-form4_1762471658.xml · nonDerivative · entry 1

John T. Kim 2024 GRAT #1 dtd. 08/09/2024 · CIK 0002034170 · Member of 10% owner group

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,194,000

F1 · balance_after: On November 4, 2025, the Reporting Person distributed 806,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to John T. Kim. John T. Kim is the sole trustee of the Reporting Person. Because John. T. Kim is the annuitant and sole trustee of the Reporting Person, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001628280-25-045367 · wk-form4_1760733589.xml · nonDerivative · entry 1

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

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 356,699

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 June 06, 2025.

SEC source: 0001628280-25-043761 · wk-form4_1759437488.xml · derivative · entry 3

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,076

Underlying: Common Stock · 8,692 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: On the Grant Date, the Reporting Person was granted 43,459 RSUs which vest in five equal quarterly installments on each of June 30, 2025, September 30, 2025, December 31, 2025, March 31, 2026, and June 30, 2026, such that 100% will be vested on June 30, 2026.

F2 · derivative.expiration_date: On the Grant Date, the Reporting Person was granted 43,459 RSUs which vest in five equal quarterly installments on each of June 30, 2025, September 30, 2025, December 31, 2025, March 31, 2026, and June 30, 2026, such that 100% will be vested on June 30, 2026.

SEC source: 0001628280-25-043761 · wk-form4_1759437488.xml · nonDerivative · entry 2

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,321

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, 2025 (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: 0001628280-25-043761 · wk-form4_1759437488.xml · nonDerivative · entry 1

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 15,046

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: 0001628280-25-043758 · wk-form4_1759437400.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,076

Underlying: Common Stock · 8,692 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: On the Grant Date, the Reporting Person was granted 43,459 RSUs which vest in five equal quarterly installments on each of June 30, 2025, September 30, 2025, December 31, 2025, March 31, 2026, and June 30, 2026, such that 100% will be vested on June 30, 2026.

F2 · derivative.expiration_date: On the Grant Date, the Reporting Person was granted 43,459 RSUs which vest in five equal quarterly installments on each of June 30, 2025, September 30, 2025, December 31, 2025, March 31, 2026, and June 30, 2026, such that 100% will be vested on June 30, 2026.

SEC source: 0001628280-25-043758 · wk-form4_1759437400.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 92,071

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, 2025 (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: 0001628280-25-043758 · wk-form4_1759437400.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 95,796

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: 0001628280-25-043755 · wk-form4_1759437312.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: 26,076

Underlying: Common Stock · 8,692 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: On February 20, 2025, the Reporting Person was granted 43,459 restricted stock units which vest in five equal quarterly installments on each of June 30, 2025, September 30, 2025, December 31, 2025, March 31, 2026, and June 30, 2026, such that 100% will be vested on June 30, 2026.

F1 · derivative.expiration_date: On February 20, 2025, the Reporting Person was granted 43,459 restricted stock units which vest in five equal quarterly installments on each of June 30, 2025, September 30, 2025, December 31, 2025, March 31, 2026, and June 30, 2026, such that 100% will be vested on June 30, 2026.

SEC source: 0001628280-25-043755 · wk-form4_1759437312.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: 366,699

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: 0001628280-25-042480 · wk-form4_1758658526.xml · nonDerivative · entry 1

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

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 358,007

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 June 06, 2025.

SEC source: 0001628280-25-042825 · wk-form4_1758832876.xml · derivative · entry 1

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,854.8917

Underlying: Common Stock · 27.3648 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.