Axcelis (NASDAQ: ACLS) CEO reports tax-withholding share disposition on RSU vesting

Rhea-AI Filing Summary

Axcelis Technologies President and CEO Russell Low reported a tax-related share disposition connected to the vesting of performance-based restricted stock units granted in May 2024. On the tax-withholding date, 5,227 shares of common stock were forfeited at $86.58 per share to cover tax obligations.

After this withholding, Low directly held 130,928 shares of Axcelis common stock, including 79,638 shares issuable upon vesting of restricted stock units that remain subject to forfeiture.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Low Russell

Role PRESIDENT AND CEO

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	5,227	$86.58	$453K

Holdings After Transaction: Common Stock — 130,928 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, 79,638 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^*

Low Russell

(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)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	PRESIDENT AND CEO

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		5,227	D(1)	$86.58(2)	130,928(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, 79,638 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
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transaction did Axcelis Technologies (ACLS) report for CEO Russell Low?

Axcelis reported a tax-withholding disposition by CEO Russell Low. He forfeited 5,227 shares of common stock to satisfy tax obligations arising from vested performance-based restricted stock units granted in May 2024, rather than executing an open-market sale.

How many Axcelis (ACLS) shares were forfeited for tax withholding by the CEO?

Russell Low forfeited 5,227 shares of Axcelis common stock for tax withholding. The shares’ value was based on the $86.58 closing price on March 2, 2026, the date the tax obligation related to vested 2024 performance-based RSUs was settled.

What price per share was used for the Axcelis (ACLS) CEO’s tax-withholding shares?

The tax-withholding disposition used a price of $86.58 per share, representing the closing price of Axcelis common stock on March 2, 2026. This price determined how many shares were needed to cover the CEO’s tax liability on the vested 2024 PRSUs.

How many Axcelis (ACLS) shares does CEO Russell Low hold after this Form 4 transaction?

After the tax-withholding disposition, Russell Low directly held 130,928 Axcelis shares. Of these, 79,638 shares are issuable upon future vesting of restricted stock units granted under the 2012 Equity Incentive Plan and remain subject to potential forfeiture.

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

The 2024 PRSUs are performance-based restricted stock units granted to the CEO in May 2024. The compensation committee determined that 150% of the target award was earned, with half vesting on February 28, 2025 and the remainder on February 28, 2026.

Was the Axcelis (ACLS) CEO’s Form 4 transaction an open-market stock sale?

No, the transaction was a tax-withholding disposition, not an open-market sale. Shares were withheld and forfeited to cover the CEO’s tax liability arising from vesting of the 2024 performance-based RSUs, using the March 2, 2026 closing share price.