Guillaume Marie Jean Rutten - 18 Feb 2026 Form 4 Insider Report for AMKOR TECHNOLOGY, INC. (AMKR)

Role: Director
Signature: /s/ Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten
Issuer symbol: AMKR
Transactions as of: 18 Feb 2026
Net transactions value: $0
Form type: 4
Filing time: 20 Feb 2026, 16:19:12 UTC
Previous filing: 18 Feb 2026
Next filing: 24 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Rutten Guillaume Marie Jean	Director	2045 EAST INNOVATION CIRCLE, TEMPE	/s/ Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten	20 Feb 2026	0001596796

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	AMKR	Common Stock	Award	$0	+10,891	+3.2%	$0.000000	350,202	18 Feb 2026	Direct	F1
transaction	AMKR	Common Stock	Award	$0	+30,587	+8.7%	$0.000000	380,789	18 Feb 2026	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	This Form 4 reports the vesting on February 18, 2026 of 10,891 shares of common stock of Amkor Technology, Inc. (the "Issuer") underlying performance-vested restricted stock units ("PSUs") granted to the Reporting Person on February 20, 2024 pursuant to the Issuer's Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic earnings per share performance goal over a one-year performance period beginning January 1, 2025 and ending on December 31, 2025.
F2	This Form 4 reports the vesting on February 18, 2026 of 30,587 shares of common stock of the Issuer's underlying PSUs granted to the Reporting Person on February 20, 2025 pursuant to the Issuer's Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic earnings per share performance goal over a one-year performance period beginning January 1, 2025 and ending on December 31, 2025.

Content

This Form 4 reports the vesting on February 18, 2026 of 10,891 shares of common stock of Amkor Technology, Inc. (the "Issuer") underlying performance-vested restricted stock units ("PSUs") granted to the Reporting Person on February 20, 2024 pursuant to the Issuer's Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic earnings per share performance goal over a one-year performance period beginning January 1, 2025 and ending on December 31, 2025.

This Form 4 reports the vesting on February 18, 2026 of 30,587 shares of common stock of the Issuer's underlying PSUs granted to the Reporting Person on February 20, 2025 pursuant to the Issuer's Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic earnings per share performance goal over a one-year performance period beginning January 1, 2025 and ending on December 31, 2025.