Axcelis (ACLS) CEO Russell Low sells 1,244 shares in planned trade

Rhea-AI Filing Summary

AXCELIS TECHNOLOGIES INC president and CEO Russell Low reported an open-market sale of 1,244 shares of common stock at $90.00 per share on March 24, 2026. After the sale, he directly holds 133,526 shares, including 83,480 shares issuable upon vesting of restricted stock units that remain subject to forfeiture.

The transaction was executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 11, 2025, indicating it was scheduled in advance rather than timed discretionarily. Overall, the sale represents a small portion of his total reported holdings.

Insider Trade Summary 10b5-1

Net Seller: 1,244 shares ($111,960)

Net Sell 1 txn

Insider Low Russell

Role PRESIDENT AND CEO

Sold 1,244 shs ($112K)

Type	Security	Shares	Price	Value
Sale	Common Stock	1,244	$90.00	$112K

Holdings After Transaction: Common Stock — 133,526 shares (Direct)

Footnotes (1)

1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 11, 2025. Of the shares held after this sale on March 24, 2026, 83,480 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture. This amount includes restricted stock units earned by the reporting person upon the achievement of 112.5% of the restricted stock units granted in 2025 based upon the achievement of 2025 performance goals.

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

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).

X

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 MASSACHUSETTS 01915

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/24/2026

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	03/24/2026		S(1)		1,244	D	$90	133,526(2)	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 transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 11, 2025.

2. Of the shares held after this sale on March 24, 2026, 83,480 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture. This amount includes restricted stock units earned by the reporting person upon the achievement of 112.5% of the restricted stock units granted in 2025 based upon the achievement of 2025 performance goals.

	/s/ Eileen J. Evans, Attorney-in-Fact	03/26/2026
	** 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)

FAQ

What did AXCELIS TECHNOLOGIES (ACLS) CEO Russell Low report in this Form 4?

Russell Low reported an open-market sale of 1,244 shares of Axcelis common stock at $90.00 per share. Following the transaction, his reported direct ownership stands at 133,526 shares, including a large component tied to restricted stock units subject to vesting and forfeiture.

At what price did the ACLS CEO sell shares and how many were sold?

He sold 1,244 shares of Axcelis common stock at a price of $90.00 per share. This is a relatively small transaction compared with his remaining reported holdings, which total 133,526 shares after the sale according to the filing’s ownership table and footnotes.

How many AXCELIS (ACLS) shares does Russell Low hold after this transaction?

After the reported sale, Russell Low directly holds 133,526 shares of Axcelis common stock. Footnotes state that 83,480 of these are issuable upon vesting of restricted stock units under the 2012 Equity Incentive Plan and remain subject to forfeiture based on plan and performance conditions.

Was the ACLS CEO’s share sale under a Rule 10b5-1 trading plan?

Yes. A footnote explains the sale was made under a Rule 10b5-1 trading plan adopted on December 11, 2025. Such plans pre-schedule trades, indicating the timing of this 1,244-share sale at $90.00 per share was set in advance rather than decided opportunistically.

What portion of Russell Low’s ACLS holdings are restricted stock units?

The filing notes that 83,480 shares in his post-transaction total are issuable upon vesting of restricted stock units. These units, granted under the 2012 Equity Incentive Plan, are subject to forfeiture and include additional units earned from achieving 112.5% of 2025 performance-based goals.

What performance detail is disclosed about the ACLS CEO’s restricted stock units?

Footnotes state that the restricted stock unit figure includes units earned when 2025 performance reached 112.5% of the 2025 restricted stock unit grant target. This indicates a performance-based component within the 83,480 units that are issuable upon vesting and still subject to forfeiture conditions.