[Form 4] AMKOR TECHNOLOGY, INC. Insider Trading Activity

Amkor Technology director Winston J. Churchill reported equity compensation activity.

Rhea-AI Filing Summary

Amkor Technology director Winston J. Churchill reported equity compensation activity. On May 13, 2026, 2025 time-vested restricted stock units and related dividend equivalent units vested, converting into 9,893 shares of common stock, bringing his direct holdings to 28,781 shares. He also received a new grant of 2,613 restricted stock units, which can convert into common stock on a one-for-one basis and will vest in full on the earlier of the first anniversary of the grant date or the company’s first annual stockholder meeting following that date. These were awarded for his service as a director and do not reflect open-market purchases or sales.

Insider Trade Summary

9,893.0573 shares exercised/converted

Exercise 3 txns

Insider CHURCHILL WINSTON J

Role Director

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units	9,893.0573	$0.00	$0.00
Grant/Award	Restricted Stock Units	2,613	$0.00	$0.00
Exercise	Common Stock	9,893	$0.00	$0.00

Holdings After Transaction: Restricted Stock Units — 2,613 contracts (Direct); Common Stock — 28,781 shares (Direct)

Footnotes (2)

1. F1. 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.
2. F2. 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.

Key Figures

Common shares acquired via RSU vesting: 9,893 shares Common shares held after transactions: 28,781 shares New RSU grant: 2,613 restricted stock units +2 more

5 metrics

Common shares acquired via RSU vesting 9,893 shares Converted from 2025 RSUs and dividend equivalent units on May 13, 2026

Common shares held after transactions 28,781 shares Direct ownership following May 13, 2026 Form 4 transactions

New RSU grant 2,613 restricted stock units Granted May 13, 2026 under 2021 Equity Incentive Plan

Original 2025 RSU grant 9,789 RSUs Granted May 15, 2025 under 2021 Equity Incentive Plan

Dividend equivalent units included 104 DEUs Converted into common stock with 2025 RSUs on May 13, 2026

Key Terms

Restricted Stock Units, dividend equivalent units, 2021 Equity Incentive Plan, time-vested, +1 more

5 terms

Restricted Stock Units financial

"On May 15, 2025, the Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. 2021 Equity Incentive Plan"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

dividend equivalent units financial

"0.0573 of the 2025 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an additional RSU"

Dividend equivalent units are bookkeeping credits that mirror cash dividends paid on actual shares, granted to holders of stock-based awards such as restricted stock units or deferred compensation. They matter to investors because they increase a company’s reported employee compensation cost and can lead to issuance of more shares or cash payouts over time, similar to extra pay linked to ownership that affects shareholder dilution and corporate cash flow.

2021 Equity Incentive Plan financial

"granted 9,789 time-vested restricted stock units pursuant to the Amkor Technology, Inc. 2021 Equity Incentive Plan, as amended"

time-vested financial

"Reporting Person was granted 9,789 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. 2021 Equity Incentive Plan"

Time-vested describes a right—such as stock options, restricted shares, or pension benefits—that becomes fully owned by an individual only after they have waited for or worked through a specified period. For investors, it matters because these delayed ownership rules affect when insiders or employees can sell shares, which influences share supply, executive incentives, and the timing of potential stock dilution or insider-driven stock sales.

award agreement financial

"pursuant to the Amkor Technology, Inc. 2021 Equity Incentive Plan, as amended and the applicable award agreement (the "2025 RSUs")"

An award agreement is a legal contract that spells out the terms of a pay or equity grant—such as stock options, restricted shares, or cash bonuses—given to an employee, director or consultant. It describes what is being granted, any conditions for keeping it (for example, earning it over time or meeting performance targets), and what happens if the person leaves or breaks rules. Investors care because these agreements affect company costs, potential share dilution and how executives are motivated and rewarded.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 05/15/2026 - 04:38 PM EDT Learn about SEC filing dates

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^*

CHURCHILL WINSTON J

(Last) (First) (Middle)

500 SE MIZNER BLVD.

APT 305A

(Street)

BOCA RATON FLORIDA 33432-6083

(City) (State) (Zip)

UNITED STATES

(Country)

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
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/13/2026

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

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

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

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	05/13/2026		M		9,893(1)	A	$0(1)	28,781(1)	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
Restricted Stock Units	(1)	05/13/2026		M			9,893.0573	(1)	(1)	Common Stock	9,893.0573	$0	0	D
Restricted Stock Units	(2)	05/13/2026		A		2,613		(2)	(2)	Common Stock	2,613	$0	2,613	D

Explanation of Responses:

1. 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.

2. 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.

Remarks:

	/s/ Mark N. Rogers, Attorney-in-Fact for Winston J. Churchill	05/15/2026
	** 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.
* Form 4: SEC 1474 (03-26)