Axcelis (ACLS) EVP forfeits 1,121 shares to cover RSU tax withholding

Rhea-AI Filing Summary

Axcelis Technologies executive Gerald M. Blumenstock reported a tax-related share disposition. On March 2, he forfeited 1,121 shares of common stock at a price of $86.58 per share to cover tax withholding triggered by the February 28, 2026 vesting of previously granted performance-based restricted stock units. After this withholding, he directly holds 17,540 shares, including 16,525 shares issuable upon vesting of restricted stock units that remain subject to forfeiture.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Blumenstock Gerald M

Role EVP, Research, Dev. & Eng.

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	1,121	$86.58	$97K

Holdings After Transaction: Common Stock — 17,540 shares (Direct)

Footnotes (1)

1. This forfeiture of shares for tax withholding purposes relates to the vesting on February 28, 2026 of performance-based restricted stock units ("2024 PRSUs") granted to the executive in May 2024. Of the 2024 PRSUs granted, 150% were determined to be earned by the executive pursuant to a resolution of the Axcelis Technologies, Inc. Compensation Committee on February 13, 2025, with half of the earned shares vesting on February 28, 2025 and the remaining half of the earned shares vesting on February 28, 2026. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested 2024 PRSUs. Represents the closing price of the Company's common stock on March 2, 2026, the date of the tax withholding. Of the shares held after the vesting of the remaining 2024 PRSUs, 16,525 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture.

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Blumenstock Gerald M

(Last) (First) (Middle)

C/O AXCELIS TECHNOLOGIES, INC.

108 CHERRY HILL DRIVE

(Street)

BEVERLY MA 01915

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
AXCELIS TECHNOLOGIES INC [ ACLS ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Research, Dev. & Eng.

3. Date of Earliest Transaction (Month/Day/Year)
03/02/2026

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	03/02/2026		F		1,121	D(1)	$86.58(2)	17,540(3)	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. This forfeiture of shares for tax withholding purposes relates to the vesting on February 28, 2026 of performance-based restricted stock units ("2024 PRSUs") granted to the executive in May 2024. Of the 2024 PRSUs granted, 150% were determined to be earned by the executive pursuant to a resolution of the Axcelis Technologies, Inc. Compensation Committee on February 13, 2025, with half of the earned shares vesting on February 28, 2025 and the remaining half of the earned shares vesting on February 28, 2026. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested 2024 PRSUs.

2. Represents the closing price of the Company's common stock on March 2, 2026, the date of the tax withholding.

3. Of the shares held after the vesting of the remaining 2024 PRSUs, 16,525 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture.

	/s/ Eileen J. Evans, Attorney-in-Fact	03/03/2026
	** Signature of Reporting Person	Date
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FAQ

What insider transaction did Axcelis (ACLS) executive Gerald M. Blumenstock report?

Gerald M. Blumenstock reported a tax-withholding disposition of shares. He forfeited 1,121 shares of Axcelis common stock on March 2, 2026 to satisfy tax obligations arising from the vesting of performance-based restricted stock units granted in 2024 under the company’s equity incentive plan.

How many Axcelis (ACLS) shares were forfeited and at what price in this Form 4?

The filing shows 1,121 shares of Axcelis common stock were forfeited. The transaction used a price of $86.58 per share, which the filing describes as the closing price of the company’s stock on March 2, 2026, the date the tax withholding occurred for the vested awards.

Why were Gerald M. Blumenstock’s Axcelis (ACLS) shares forfeited in this transaction?

The shares were forfeited solely to cover tax withholding obligations. They relate to 2024 performance-based restricted stock units that vested on February 28, 2026 after being earned at 150% of target, with the company retaining shares equal in value to the associated tax liability.

What are the 2024 performance-based RSUs mentioned in the Axcelis (ACLS) Form 4?

The 2024 performance-based RSUs are equity awards granted in May 2024. The compensation committee later determined 150% of the target units were earned, with half vesting on February 28, 2025 and the remaining half vesting on February 28, 2026, triggering related tax-withholding share forfeitures.

How many Axcelis (ACLS) shares does Gerald M. Blumenstock hold after this tax-withholding event?

After the transaction, Blumenstock holds 17,540 shares of Axcelis common stock directly. Footnote disclosure explains that 16,525 of these are issuable upon future vesting of restricted stock units granted under the 2012 Equity Incentive Plan and remain subject to potential forfeiture.

Are the remaining Axcelis (ACLS) restricted stock units still subject to forfeiture?

Yes. The filing states that 16,525 shares are issuable upon vesting of restricted stock units. These units were granted under the 2012 Equity Incentive Plan and are explicitly described as being subject to forfeiture, meaning the shares are not guaranteed until vesting conditions are fully satisfied.