Axcelis (ACLS) EVP sells 1,161 shares, retains 20,493 RSU-linked shares

Rhea-AI Filing Summary

Axcelis Technologies executive vice president Gerald M. Blumenstock sold 1,161 shares of common stock in an open-market transaction at $152.70 per share on May 21, 2026. After this sale, a total of 20,493 shares are reported as issuable upon vesting of restricted stock units granted under the 2012 Equity Incentive Plan and remain subject to forfeiture.

Insider Trade Summary

Net Seller: 1,161 shares ($177,285)

Net Sell 1 txn

Insider Blumenstock Gerald M

Role EVP, Research, Dev. & Eng.

Sold 1,161 shs ($177K)

Type	Security	Shares	Price	Value
Sale	Common Stock	1,161	$152.70	$177K

Holdings After Transaction: Common Stock — 20,493 shares (Direct, null)

Footnotes (1)

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Key Figures

Shares sold: 1,161 shares Sale price: $152.70 per share Shares reported after transaction: 20,493 shares +1 more

4 metrics

Shares sold 1,161 shares Open-market sale of common stock on May 21, 2026

Sale price $152.70 per share Price for the 1,161 shares of common stock sold

Shares reported after transaction 20,493 shares Issuable upon vesting of restricted stock units after sale

Net share change 1,161 shares sold Net-sell direction per transaction summary

Key Terms

open-market sale, restricted stock units, 2012 Equity Incentive Plan

3 terms

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

restricted stock units financial

"20,493 shares were issuable on vesting of restricted stock units granted"

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"

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).

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 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)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/21/2026

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	05/21/2026		S		1,161	D	$152.7	20,493(1)	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. Of the shares held after this sale on May 21, 2026, 20,493 shares 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	05/22/2026
	** 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 (ACLS) report for Gerald M. Blumenstock?

Axcelis reported that EVP Gerald M. Blumenstock completed an open-market sale of company common stock. He sold 1,161 shares of Axcelis Technologies common stock in a single transaction on May 21, 2026, as disclosed in a Form 4 insider trading report.

How many Axcelis (ACLS) shares did Gerald M. Blumenstock sell and at what price?

Gerald M. Blumenstock sold 1,161 shares of Axcelis common stock at a price of $152.70 per share. The transaction was classified as an open-market sale, indicating the shares were sold on the public market rather than through a private arrangement.

What are Gerald M. Blumenstock’s reported Axcelis (ACLS) holdings after this transaction?

Following the sale, the Form 4 reports 20,493 shares associated with Gerald M. Blumenstock. According to the footnote, these shares are issuable upon vesting of restricted stock units granted under the 2012 Equity Incentive Plan and are still subject to potential forfeiture.

What role does Gerald M. Blumenstock hold at Axcelis (ACLS)?

Gerald M. Blumenstock serves as executive vice president for Research, Development and Engineering at Axcelis Technologies. His position as an officer makes his equity transactions reportable under SEC rules, leading to public disclosure through Form 4 filings.

What does the restricted stock unit footnote mean for Axcelis (ACLS) shares?

The footnote explains that the 20,493 shares reported after the sale are tied to restricted stock units. These shares will only be issued if the units vest under the 2012 Equity Incentive Plan, and they can be forfeited if vesting conditions are not met.