Eileen J. Evans - 16 Dec 2025 Form 4 Insider Report for AXCELIS TECHNOLOGIES INC (ACLS)

Role: EVP, General Counsel and Sec'y
Signature: /s/ Eileen J. Evans
Issuer symbol: ACLS
Transactions as of: 16 Dec 2025
Net transactions value: -$118,949
Form type: 4
Filing time: 18 Dec 2025, 17:05:05 UTC
Previous filing: 15 May 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Evans Eileen	EVP, General Counsel and Sec'y	108 CHERRY HILL DRIVE, BEVERLY	/s/ Eileen J. Evans	18 Dec 2025	0001715912

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ACLS	Common Stock	Tax liability	$118,949	-1,378	-5.3%	$86.32	24,406	16 Dec 2025	Direct	F1, F2, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	This forfeiture of shares for tax withholding purposes relates to the vesting on December 16, 2025 of 2,850 service vesting restricted stock units granted to the executive in December 2024. 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 restricted stock units.
F2	Represents the closing price of the common stock on the date of the tax withholding.
F3	Of the shares held after this vesting event on December 16, 2025, 22,934 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture.