Amkor (AMKR) Insider Sale: CEO Disposes 10,000 Shares Under 10b5-1 Plan

Rhea-AI Filing Summary

Guillaume M. J. Rutten, President and CEO and director of Amkor Technology (AMKR), reported a sale of 10,000 shares of AMKR common stock on 09/23/2025 at $30 per share under a pre-existing Rule 10b5-1 trading plan adopted on 06/06/2025. After the transaction, the reporting person beneficially owned 358,007 shares. The Form 4 was signed by an attorney-in-fact and indicates the sale was executed pursuant to the written plan, which provides an affirmative defense under Rule 10b5-1. No derivative transactions or other changes in ownership were reported on this filing.

Positive

• Transaction executed under a Rule 10b5-1 trading plan, which provides an affirmative defense and clarity on insider intent
• Transparent disclosure of post-transaction beneficial ownership (358,007 shares) in the Form 4

Negative

• Insider sale of 10,000 shares reduces executive ownership, which some investors may view negatively

Insights

Securities Analyst

TL;DR: Routine insider sale under a 10b5-1 plan; modestly reduces CEO's share count but provides compliance clarity.

The sale of 10,000 shares at $30 is a routine non-derivative disposition and represents a small portion of the CEO's remaining 358,007 shares. Because the transaction was executed under a Rule 10b5-1 plan adopted June 6, 2025, it reduces ambiguity around intent and trading timing. For investors, this filing documents liquidity taken by management but does not indicate changes to compensation structure, operational performance, or material corporate events.

Corporate Governance Expert

TL;DR: Use of a documented 10b5-1 plan is governance-positive; the sale itself appears routine and non-material.

From a governance perspective, the reporting person disclosed the 10b5-1 trading plan adoption date and the transaction date, which aligns with best practices for insider trading compliance. The reduction to 358,007 shares post-sale is disclosed transparently. There is no evidence in this filing of opportunistic timing or related-party transactions, and no derivatives or other complex instruments were reported.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Rutten Guillaume Marie Jean

(Last) (First) (Middle)

2045 EAST INNOVATION CIRCLE

(Street)

TEMPE AZ 85284

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
AMKOR TECHNOLOGY, INC. [ AMKR ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

3. Date of Earliest Transaction (Month/Day/Year)
09/23/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/23/2025		S(1)		10,000	D	$30	358,007	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. 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.

Remarks:

	/s/ Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten	09/23/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did AMKR insider Guillaume Rutten report on Form 4?

He reported a sale of 10,000 shares of Amkor Technology common stock on 09/23/2025 at $30 per share under a Rule 10b5-1 plan.

How many AMKR shares does the reporting person own after the sale?

358,007 shares of AMKR common stock are beneficially owned following the reported transaction.

Was the sale part of an approved trading plan or pre-scheduled transaction?

Yes; the sale was effected pursuant to a Rule 10b5-1 trading plan adopted on 06/06/2025.

Did the Form 4 report any derivative transactions or option exercises?

No derivative securities, options, or other conversions were reported in this filing.

Who signed the Form 4 for Guillaume Rutten?

Mark N. Rogers, Attorney-in-Fact, signed the Form 4 on behalf of the reporting person on 09/23/2025.