Russell Low (ACLS) trims stake with 7,468-share Rule 10b5-1 sale

Rhea-AI Filing Summary

Axcelis Technologies President and CEO Russell Low reported an open-market sale of 7,468 shares of Common Stock at $156.75 per share on May 6, 2026. The transaction was executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 11, 2025.

After this sale, Low directly holds 123,570 shares, including 83,480 shares issuable upon vesting of restricted stock units granted under the 2012 Equity Incentive Plan that remain subject to forfeiture. This filing reflects a planned, partial reduction while maintaining a significant ongoing equity position.

Insights

Equity compensation and insider-trading analyst

CEO’s 7,468-share 10b5-1 sale looks routine relative to remaining stake.

CEO Russell Low sold 7,468 Axcelis shares at $156.75 per share in an open-market transaction classified as a sale. The filing specifies this was done under a Rule 10b5-1 trading plan adopted on December 11, 2025, indicating the trade was pre-scheduled rather than opportunistic.

Following the sale, Low directly owns 123,570 shares, and 83,480 of these are issuable upon vesting of restricted stock units under the 2012 Equity Incentive Plan and remain subject to forfeiture. The sale represents only a portion of his holdings, so the filing mainly confirms ongoing equity exposure with a modest, pre-planned liquidity event.

Insider Trade Summary 10b5-1

Net Seller: 7,468 shares ($1,170,609)

Net Sell 1 txn

Insider Low Russell

Role PRESIDENT AND CEO

Sold 7,468 shs ($1.17M)

Type	Security	Shares	Price	Value
Sale	Common Stock	7,468	$156.75	$1.17M

Holdings After Transaction: Common Stock — 123,570 shares (Direct, null)

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 May 6, 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.

Key Figures

Shares sold: 7,468 shares Sale price per share: $156.75 per share Shares held after transaction: 123,570 shares +2 more

5 metrics

Shares sold 7,468 shares Open-market sale on May 6, 2026

Sale price per share $156.75 per share Common Stock transaction price

Shares held after transaction 123,570 shares Direct holdings following sale

RSU-linked shares 83,480 shares Issuable upon vesting under 2012 Equity Incentive Plan, subject to forfeiture

Rule 10b5-1 plan adoption date December 11, 2025 Plan governing the May 6, 2026 sale

Key Terms

Rule 10b5-1 trading plan, restricted stock units, 2012 Equity Incentive Plan, subject to forfeiture

4 terms

Rule 10b5-1 trading plan regulatory

"This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

restricted stock units financial

"83,480 were issuable on vesting of restricted stock units granted to the reporting person"

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.

2012 Equity Incentive Plan financial

"restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan"

subject to forfeiture regulatory

"83,480 were issuable on vesting of restricted stock units ... 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

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)
05/06/2026

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	05/06/2026		S(1)		7,468	D	$156.75	123,570(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 May 6, 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.

	/s/ Eileen J. Evans, Attorney-in-Fact	05/07/2026
	** 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 insider transaction did Axcelis Technologies (ACLS) report for CEO Russell Low?

Axcelis CEO Russell Low sold 7,468 shares of Common Stock in an open-market transaction at $156.75 per share on May 6, 2026. The sale was disclosed in a Form 4 filing and executed under a Rule 10b5-1 trading plan previously adopted.

Was the Axcelis (ACLS) CEO’s May 6, 2026 stock sale pre-planned?

Yes. The Form 4 states the sale was made pursuant to a Rule 10b5-1 trading plan adopted on December 11, 2025. Such plans pre-schedule trades, reducing the significance of short-term timing decisions and framing the sale as routine portfolio management.

How many Axcelis (ACLS) shares does CEO Russell Low hold after the reported sale?

After selling 7,468 shares, Russell Low directly holds 123,570 shares of Axcelis Common Stock. According to the filing, 83,480 of these shares are issuable upon vesting of restricted stock units under the 2012 Equity Incentive Plan and remain subject to forfeiture.

What portion of the Axcelis (ACLS) CEO’s holdings are restricted stock units?

The filing notes that 83,480 of the shares associated with CEO Russell Low’s post-transaction holdings are issuable upon vesting of restricted stock units. These RSU-based shares come from grants under the 2012 Equity Incentive Plan and remain subject to forfeiture until vesting conditions are met.

What is the significance of the Rule 10b5-1 plan in the Axcelis (ACLS) Form 4?

The Rule 10b5-1 plan indicates the CEO’s sale was arranged in advance, following a preset schedule or conditions. This structure is designed to separate trading decisions from non-public information, so the transaction is generally viewed as a routine, compliance-focused liquidity event.