Amkor (AMKR) Insider Filing: 4.46M-Share Disposition by Director with Major Indirect Holdings

Rhea-AI Filing Summary

Susan Y. Kim, a director and reported 10% owner of Amkor Technology, Inc. (AMKR), filed a Form 4 disclosing a disposition of 4,456,494 shares on 09/23/2025. The filing details numerous indirect holdings through entities and trusts for which she serves as trustee, general partner or manager, including 19,484,809 shares held by Sujochil, LP, 16,710,668 shares held by an LLC treated as a corporation, 4,418,610 shares held by family trusts (excluding GRATs), 3,800,000 shares held by GRATs, 3,483,000 shares held by GRATs of which she was settlor, and 3,789,479 shares indirectly owned via Sujoda Investments, LP. The filer disclaims beneficial ownership except for her pecuniary interest. The filing also reports dividend equivalent units accrued on 09/23/2025 related to time-vested RSUs granted 05/15/2025.

Positive

• Detailed disclosure of indirect holdings and roles (trustee, general partner, manager) enhances transparency
• Accrual of dividend equivalent units on RSUs is explicitly reported, clarifying compensation-related movements

Negative

• Material disposition of 4,456,494 shares on 09/23/2025 by a director and 10% owner
• Concentrated indirect ownership across multiple entities (e.g., 19,484,809 shares via Sujochil, LP) which could be material to shareholders

Insights

Financial Analyst

TL;DR: A material insider sale of 4.46 million shares by a director and 10% owner is disclosed; significant indirect holdings remain concentrated.

The Form 4 shows a large, explicit disposition of 4,456,494 shares on 09/23/2025 by Susan Y. Kim while she continues to hold substantial indirect positions through multiple entities and trusts, including a 19.5 million share position via Sujochil, LP and a 16.7 million share position via a manager-controlled LLC. The filing follows Section 16 disclosure norms and includes accrual of dividend equivalent units for RSUs granted 05/15/2025. For investors, the combination of a sizable sale and continued concentrated indirect ownership is material information for assessing insider activity and potential liquidity events.

Corporate Governance Expert

TL;DR: Disclosure is comprehensive about indirect ownership and includes customary disclaimers of beneficial ownership.

The submission provides detailed footnotes describing trustee, general partner and manager roles that explain why the Reporting Person is treated as having pecuniary interests in multiple large holdings. The filing expressly disclaims beneficial ownership except to the extent of pecuniary interest and documents dividend equivalent units tied to RSUs. The level of detail supports transparency under Section 16, though the simultaneous large disposition and extensive indirect holdings warrant attention from governance and compliance perspectives.

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

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

1. Name and Address of Reporting Person^*

KIM SUSAN Y

(Last) (First) (Middle)

C/O SIANA CARR O'CONNOR & LYNAM

1500 EAST LANCASTER AVENUE

(Street)

PAOLI PA 19301-9713

(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	X	10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of 10% owner group (10)

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								4,456,494	D
Common Stock								19,484,809(1)(2)(3)	I	By Sujochil, LP
Common Stock								16,710,668(1)(2)(3)	I	By Kim Capital Partners - KCP, LLC
Common Stock								4,418,610(1)(2)(3)	I	By trusts (excl. GRATs)
Common Stock								3,789,479(1)(2)(3)(4)	I	By Sujoda Investments, LP
Common Stock								3,483,000(1)(2)(3)	I	By own GRATs
Common Stock								2,200,000(1)(2)(3)	I	By James J. Kim 2024 GRAT dtd. 8/5/24
Common Stock								1,600,000(1)(2)(3)	I	By Agnes C. Kim 2024 GRAT dtd. 8/5/24

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
Restricted Stock Units	(5)	09/23/2025		A		27.3648		(5)	(5)	Common Stock	27.3648	$0	9,854.8917	D

Explanation of Responses:

1. The Reporting Person disclaims beneficial ownership of these securities, except to the extent of the Reporting Person's pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of the Reporting Person's pecuniary interest therein, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"), or for any other purpose.

2. The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 4,418,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 3,800,000 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 3,483,000 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

3. (Continued from Footnote 3) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 9, below, a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

4. The sole general partner of Sujoda Investments, LP is Sujoda Management, LLC. The Reporting Person is one of three members of Sujoda Management, LLC. Sujoda Management, LLC is being treated as a limited partnership for purposes of Section 16, and, pursuant to the Form 4 instructions, the Reporting Person has elected to treat all of the shares of the Issuer's Common Stock owned by Sujoda Investments, LP as beneficially owned by the Reporting Person.

5. 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.

Remarks:

(6) The Reporting Person states that the filing of this Form 4 shall not be deemed an admission that the Reporting Person is the beneficial owner of the reported securities owned by the other members of the group, for the purpose of Section 16, or for any other purpose.

	/s/ Mark N. Rogers, Attorney-in-Fact for Susan Y. Kim	09/25/2025
	** 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 Susan Y. Kim report on Form 4 for AMKR?

She reported a disposition of 4,456,494 shares on 09/23/2025 and detailed multiple indirect holdings through entities and trusts.

How many shares does Sujochil, LP hold according to the filing?

Sujochil, LP is reported to own 19,484,809 shares of Amkor Technology, Inc.

Does the filing show any RSU or dividend-equivalent activity for AMKR?

Yes. The filing reports dividend equivalent units accrued on 09/23/2025 related to time-vested RSUs granted on 05/15/2025.

Does Susan Y. Kim claim direct beneficial ownership of all reported shares?

No. The Reporting Person disclaims beneficial ownership except to the extent of her pecuniary interest and explains holdings arise from trustee, partner or manager roles.

What indirect holdings are disclosed in the Form 4?

Key indirect holdings include: 19,484,809 shares (Sujochil, LP), 16,710,668 shares (manager-controlled LLC), 4,418,610 shares (family trusts excluding GRATs), 3,800,000 shares (GRATs), 3,483,000 shares (GRATs where she was settlor), and 3,789,479 shares (Sujoda Investments, LP).