Tily Gil C.

SEC source: 0001628280-26-063431 · wk-form4_1790282577.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,619.5144

Underlying: Common Stock · 3.9978 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 22, 2026 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 13, 2026. 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 22, 2026 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 13, 2026. 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 22, 2026 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 13, 2026. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-26-045572 · wk-form4_1782420460.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,615.5166

Underlying: Common Stock · 2.5166 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on June 23, 2026 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 13, 2026. 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 June 23, 2026 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 13, 2026. 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 June 23, 2026 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 13, 2026. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-26-035656 · wk-form4_1778877419.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,613

Underlying: Common Stock · 2,613 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents shares of common stock underlying RSUs granted on May 13, 2026 (the "Grant Date") pursuant to the Plan (the "2026 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2026 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2026 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.exercise_date: Represents shares of common stock underlying RSUs granted on May 13, 2026 (the "Grant Date") pursuant to the Plan (the "2026 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2026 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2026 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.expiration_date: Represents shares of common stock underlying RSUs granted on May 13, 2026 (the "Grant Date") pursuant to the Plan (the "2026 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2026 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2026 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

SEC source: 0001628280-26-035656 · wk-form4_1778877419.xml · derivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 9,893.0573 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 May 15, 2025, the Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2025 RSUs"). In connection with the vesting of the 2025 RSUs on May 13, 2026: (i) 0.0573 of the 2025 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2025 RSUs, including 104 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.exercise_date: On May 15, 2025, the Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2025 RSUs"). In connection with the vesting of the 2025 RSUs on May 13, 2026: (i) 0.0573 of the 2025 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2025 RSUs, including 104 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.expiration_date: On May 15, 2025, the Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2025 RSUs"). In connection with the vesting of the 2025 RSUs on May 13, 2026: (i) 0.0573 of the 2025 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2025 RSUs, including 104 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001628280-26-035656 · wk-form4_1778877419.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 118,699

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.

F1 · shares: On May 15, 2025, the Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2025 RSUs"). In connection with the vesting of the 2025 RSUs on May 13, 2026: (i) 0.0573 of the 2025 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2025 RSUs, including 104 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · price: On May 15, 2025, the Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2025 RSUs"). In connection with the vesting of the 2025 RSUs on May 13, 2026: (i) 0.0573 of the 2025 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2025 RSUs, including 104 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · balance_after: On May 15, 2025, the Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2025 RSUs"). In connection with the vesting of the 2025 RSUs on May 13, 2026: (i) 0.0573 of the 2025 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2025 RSUs, including 104 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001628280-26-034646 · wk-form4_1778704699.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 108,806

SEC source: 0001628280-26-023401 · wk-form4_1775170826.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,893.0573

Underlying: Common Stock · 18.1563 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on March 31, 2026 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 March 31, 2026 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 March 31, 2026 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.

SEC source: 0001628280-25-058862 · wk-form4_1767014545.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 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 December 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 December 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.

SEC source: 0001628280-25-057392 · wk-form4_1765920233.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 123,806

F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $45.91 to $46.83. 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: 0001628280-25-042821 · wk-form4_1758832757.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · 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 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 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 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.

SEC source: 0001047127-25-000132 · wk-form4_1751060518.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,827.5269

Underlying: Common Stock · 38.5269 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on June 25, 2025 with respect to time-vested restricted stock units ("RSUs") of 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 June 25, 2025 with respect to time-vested restricted stock units ("RSUs") of 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 June 25, 2025 with respect to time-vested restricted stock units ("RSUs") of 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.

SEC source: 0001047127-25-000112 · wk-form4_1747428158.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,789

Underlying: Common Stock · 9,789 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents shares of common stock underlying RSUs granted on May 15, 2025 (the "Grant Date") pursuant to the Plan (the "2025 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2025 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2025 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.exercise_date: Represents shares of common stock underlying RSUs granted on May 15, 2025 (the "Grant Date") pursuant to the Plan (the "2025 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2025 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2025 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.expiration_date: Represents shares of common stock underlying RSUs granted on May 15, 2025 (the "Grant Date") pursuant to the Plan (the "2025 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2025 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2025 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

SEC source: 0001047127-25-000112 · wk-form4_1747428158.xml · derivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 6,017.0342 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 May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · shares: On May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.exercise_date: On May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.expiration_date: On May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.underlying_shares: On May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001047127-25-000112 · wk-form4_1747428158.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 143,806

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 · shares: On May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · price: On May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · balance_after: On May 14, 2024, the Reporting Person was granted 5,855 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2024 RSUs"). In connection with the vesting of the 2024 RSUs on May 14, 2025: (i) 0.0342 of the 2024 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2024 RSUs, including 162 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001047127-25-000064 · wk-form4_1743797162.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,017.0342

Underlying: Common Stock · 25.9877 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on April 2, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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 April 2, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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 April 2, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001047127-24-000229 · wk-form4_1735235558.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,991.0465

Underlying: Common Stock · 108.7979 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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 December 23, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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 December 23, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001047127-24-000191 · wk-form4_1727297197.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,882.2486

Underlying: Common Stock · 14.864 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 23, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001047127-24-000137 · wk-form4_1719438075.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,867.3846

Underlying: Common Stock · 12.3846 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on June 24, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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 June 24, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. 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 June 24, 2024 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 14, 2024. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001047127-24-000104 · wk-form4_1715897827.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,855

Underlying: Common Stock · 5,855 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents shares of common stock underlying RSUs granted on May 14, 2024 (the "Grant Date") pursuant to the Plan (the "2024 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2024 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2024 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.exercise_date: Represents shares of common stock underlying RSUs granted on May 14, 2024 (the "Grant Date") pursuant to the Plan (the "2024 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2024 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2024 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.expiration_date: Represents shares of common stock underlying RSUs granted on May 14, 2024 (the "Grant Date") pursuant to the Plan (the "2024 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2024 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2024 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

SEC source: 0001047127-24-000104 · wk-form4_1715897827.xml · derivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 8,571.0421 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 May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · shares: On May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.exercise_date: On May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.expiration_date: On May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.underlying_shares: On May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001047127-24-000104 · wk-form4_1715897827.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 137,789

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 · shares: On May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · price: On May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · balance_after: On May 16, 2023, the Reporting Person was granted 8,478 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2023 RSUs"). In connection with the vesting of the 2023 RSUs on May 14, 2024: (i) 0.0421 of the 2023 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2023 RSUs, including 93 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001047127-24-000100 · wk-form4_1715117414.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 20,000 shares

Expires 2031-05-18

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 18, 2021 and vested in full on May 17, 2022.

SEC source: 0001047127-24-000100 · wk-form4_1715117414.xml · nonDerivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 129,218

F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $32.14 to $32.31. 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: 0001047127-24-000100 · wk-form4_1715117414.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 149,218

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: 0001047127-24-000079 · wk-form4_1712182917.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,571.0421

Underlying: Common Stock · 20.9884 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on April 1, 2024. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on April 1, 2024. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on April 1, 2024. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001047127-23-000064 · wk-form4_1703712621.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,550.0537

Underlying: Common Stock · 19.5331 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 26, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 26, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 26, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001047127-23-000039 · wk-form4_1701900258.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 129,218

SEC source: 0001209191-23-050672 · doc4.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001209191-23-040088 · doc4.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,502.1218

Underlying: Common Stock · 24.1218 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on June 26, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on June 26, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on June 26, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on June 26, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on June 26, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001209191-23-030844 · doc4.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,478

Underlying: Common Stock · 8,478 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents shares of common stock underlying RSUs granted on May 16, 2023 (the "Grant Date") pursuant to the Plan (the "2023 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2023 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuers first annual meeting of stockholders immediately following the Grant Date. The 2023 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.exercise_date: Represents shares of common stock underlying RSUs granted on May 16, 2023 (the "Grant Date") pursuant to the Plan (the "2023 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2023 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuers first annual meeting of stockholders immediately following the Grant Date. The 2023 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

F2 · derivative.expiration_date: Represents shares of common stock underlying RSUs granted on May 16, 2023 (the "Grant Date") pursuant to the Plan (the "2023 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2023 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuers first annual meeting of stockholders immediately following the Grant Date. The 2023 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

SEC source: 0001209191-23-030844 · doc4.xml · derivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 8,809.4075 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 May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · shares: On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.exercise_date: On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.expiration_date: On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · derivative.underlying_shares: On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001209191-23-030844 · doc4.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 138,027

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 · shares: On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · price: On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

F1 · balance_after: On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis.

SEC source: 0001209191-23-020556 · doc4.xml · derivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,809.4075

Underlying: Common Stock · 26.1076 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on March 20, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · shares: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on March 20, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.exercise_date: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on March 20, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.expiration_date: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on March 20, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.underlying_shares: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on March 20, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · balance_after: As previously reported in a Form 4 filed by the Reporting Person on May 19, 2022 (the "Original Form 4"), 8,706 shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units (the "RSUs") were granted to the Reporting Person on May 17, 2022. Pursuant to the award agreement for the RSUs, dividend equivalent units ("DEUs") accrue with respect to the RSUs when and as dividends are paid on the Issuer's common stock. In the Original Form 4 and the Form 4 filed by the Reporting Person on March 1, 2023, the RSUs were incorrectly reported in Table I. Table I, Column 5 has been adjusted to include the proper number of non-derivative securities beneficially owned by the Reporting Person, and Table II, Column 9 of this Form 4 has been adjusted to include the RSUs and reflects the proper number of RSUs beneficially owned by the Reporting Person, in each case as of the filing date of this Form 4.

SEC source: 0001209191-23-014207 · doc4.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 20,000 shares

Expires 2030-05-19

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 19, 2020 and vested in full on May 18, 2021.

SEC source: 0001209191-23-014207 · doc4.xml · nonDerivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 137,924

F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.79 to $25.85.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: 0001209191-23-014207 · doc4.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 157,924

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: 0001209191-22-062937 · doc4.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,783.2999

Underlying: Common Stock · 26.7602 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 27, 2022. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 27, 2022. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on December 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001209191-22-051483 · doc4.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,756.5397

Underlying: Common Stock · 25.9881 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 26, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 26, 2022. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 26, 2022. 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 26, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 26, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001209191-22-039870 · doc4.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,730.5516

Underlying: Common Stock · 24.5516 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on June 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · shares: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on June 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.exercise_date: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on June 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.expiration_date: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on June 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.underlying_shares: Represents DEUs accrued with respect to the RSUs upon the Issuer's payment of a dividend on June 27, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · balance_after: As previously reported in a Form 4 filed by the Reporting Person on May 19, 2022 (the "Original Form 4"), 8,706 shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units (the "RSUs") were granted to the Reporting Person on May 17, 2022. Pursuant to the award agreement for the RSUs, dividend equivalent units ("DEUs") accrue with respect to the RSUs when and as dividends are paid on the Issuer's common stock. In the Original Form 4, the RSUs were incorrectly reported in Table I. Table II, Column 9 of this Form 4 has been adjusted to include the RSUs and reflects the proper number of RSUs beneficially owned by the Reporting Person as of the filing date of this Form 4.

SEC source: 0001209191-22-030656 · doc4.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 137,924

F1 · shares: Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units granted on May 17, 2022 (the "Grant Date") pursuant to the Issuer's Equity Incentive Plan (the "RSUs"). Subject to the terms and conditions of the applicable award agreement, the RSUs will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of the stockholders immediately following the Grant Date. The RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

SEC source: 0001209191-21-048970 · doc4.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 129,218

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.47 to $24.79. 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: 0001209191-21-034069 · doc4.xml · derivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,000

Underlying: Common Stock · 20,000 shares

Expires 2031-05-18

F2 · derivative.exercise_date: These options vest 100% on the earlier of the first anniversary of the grant date or the date of the first annual meeting of stockholders following the grant date.

SEC source: 0001209191-21-034069 · doc4.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 144,218

F1 · shares: These are restricted shares which vest 100% on the earlier of the first anniversary of the grant date or the date of the first annual meeting of stockholders following the grant date.

SEC source: 0001209191-21-016864 · doc4.xml · derivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 10,938 shares

Expires 2027-02-27

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 was granted on February 27, 2017 and vests as follows: 25% of the shares vest on the first anniversary of the grant date and 1/16 of the option vests each quarter thereafter, such that 100% of the option will vest on the fourth anniversary of the grant date.

SEC source: 0001209191-21-016864 · doc4.xml · nonDerivative · entry 2

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 141,124

SEC source: 0001209191-21-016864 · doc4.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 147,489

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 · shares: Exempt purchase under Section 16b-3. Transaction executed as net exercise executed with company, in which no shares were purchased or sold in the open market.

SEC source: 0001209191-21-010761 · doc4.xml · derivative · entry 6

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 20,000 shares

Expires 2029-06-07

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 was granted on June 7, 2019 and vests as follows: the options vest 100% on the earlier of the first anniversary of the grant date or the date of the first annual meeting of stockholders following the grant date.

SEC source: 0001209191-21-010761 · doc4.xml · derivative · entry 5

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,938

Underlying: Common Stock · 64,062 shares

Expires 2027-02-27

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 was granted on February 27, 2017 and vests as follows: 25% of the shares vest on the first anniversary of the grant date and 1/16 of the option vests each quarter thereafter, such that 100% of the option will vest on the fourth anniversary of the grant date.

SEC source: 0001209191-21-010761 · doc4.xml · nonDerivative · entry 4

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 136,551

SEC source: 0001209191-21-010761 · doc4.xml · nonDerivative · entry 3

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 142,712

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 · shares: Exempt purchase under Section 16b-3. Transaction executed as net exercise executed with company, in which no shares were purchased or sold in the open market.