[Form 4] Amkor Technology Inc Insider Trading Activity

Rhea-AI Filing Summary

Form 4 filing overview – Amkor Technology, Inc. (AMKR), filed 27 June 2025. The report covers insider Susan Y. Kim, who is listed as Director, 10% Owner, member of a 10%-owner group and holder of multiple family-related trusts and entities.

New transaction: On 25 June 2025 Kim acquired 38.5269 Restricted Stock Units (classified as dividend-equivalent units, “DEUs”) that accrued automatically on outstanding RSUs because Amkor paid a dividend the same day. The DEUs carry the same vesting terms as the original May 15 2025 RSU grant. No sales or cash purchases were reported.

Post-transaction beneficial ownership (non-derivative common shares):

• Directly held: 3,738,492 shares.
• Indirectly held via GRATs, family trusts and investment partnerships: 57,130,987 shares.
• Total reported beneficial interest: ≈60,869,479 common shares (subject to footnote disclaimers).

Post-transaction derivative holdings: 9,827.5269 RSUs (includes the newly added 38.5269 DEUs).

Key footnotes: (1-4) Kim serves as trustee, general partner or manager for multiple GRATs, trusts and LP/LLC vehicles; beneficial ownership is reported on a pecuniary-interest basis yet disclaimed where appropriate. (5) The only transaction is the automatic DEU accrual described above. (6) Filing does not admit beneficial ownership of securities held by other group members.

Investor takeaways: The filing reflects routine dividend-related RSU accretion and provides an updated snapshot of a large insider holding (~61 million shares). No open-market purchases or sales occurred, so immediate market impact is likely minimal.

Insights

Securities Analyst

TL;DR: Routine dividend-driven RSU accrual; no buying or selling, neutral impact.

The only reportable event is the issuance of 38.5269 DEUs tied to the 25 June 2025 dividend. Given Amkor’s ~250 million share float, the incremental dilution is de minimis (<0.00002%). The larger story is Susan Y. Kim’s continued control of roughly 61 million shares through a complex trust and partnership structure, reaffirming the Kim family’s dominant governance position. Because no cash outlay or disposition occurred, there is no directional trading signal. I classify the filing as informational, not price-moving.

Corporate Governance Expert

TL;DR: Filing underscores concentrated family control; governance implications persist.

Kim’s aggregate stake, reported across GRATs, LPs, LLCs and direct holdings, approaches one-quarter of Amkor’s shares outstanding, sustaining the family’s veto-level influence over strategic decisions. The addition of 38.5269 DEUs is mechanistic and immaterial financially, but it updates the Section 16 ledger and illustrates rigorous compliance. Investors should note the layered entities—Sujochil LP, Kim Capital Partners, multiple GRATs—that insulate tax and estate exposure while consolidating voting power. While not impactful to valuation today, the governance concentration remains a structural risk/benefit depending on shareholder preferences.

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).

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^*

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 (6)

3. Date of Earliest Transaction (Month/Day/Year)
06/25/2025

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								3,738,492	D
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
Common Stock								3,587,004(1)(2)(3)	I	By James J. Kim 2023 GRAT dtd. 4/26/23
Common Stock								2,298,001(1)(2)(3)	I	By Agnes C. Kim 2023 GRAT dtd. 4/26/23
Common Stock								3,483,000(1)(2)(3)	I	By own GRATs
Common Stock								4,418,610(1)(2)(3)	I	By trusts (excl. GRATs)
Common Stock								3,347,890(1)(2)(3)(4)	I	By Sujoda Investments, LP
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

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)	06/25/2025		A		38.5269		(5)	(5)	Common Stock	38.5269	$0	9,827.5269	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 Amkor Technology, Inc. (the "Issuer"); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 9,685,005 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 2) (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 4, a member of Sujoda Management, LLC, which indirectly owns 3,347,890 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 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.

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.

	Mark N. Rogers, Attorney-in-Fact for Susan Y. Kim	06/27/2025
	** 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 transaction did Susan Y. Kim report in the June 27 2025 Form 4 for AMKR?

She reported the automatic acquisition of 38.5269 dividend-equivalent restricted stock units on June 25 2025 tied to Amkor’s dividend.

How many Amkor shares does Susan Y. Kim now beneficially own?

The filing shows a total beneficial interest of roughly 60.87 million common shares held directly and through multiple trusts and partnerships.

Did Susan Y. Kim sell any AMKR shares in this filing?

No. No sales or open-market purchases were disclosed; the only change was a minor RSU accrual.

What are dividend-equivalent units (DEUs) mentioned in the filing?

DEUs are additional RSUs credited when a dividend is paid; they vest under the same terms as the underlying RSUs.

Why does the filing list multiple GRATs, LPs, and LLCs for Kim’s holdings?

These entities reflect estate and tax planning structures through which Kim holds Amkor shares while retaining voting or pecuniary interests.