Axcelis (ACLS) EVP Tatnall has 907 shares withheld for RSU tax obligations

Rhea-AI Filing Summary

Axcelis Technologies executive Christopher Tatnall had 907 shares of common stock withheld for taxes in connection with restricted stock units vesting. The tax withholding was valued at $131.02 per share, based on the closing price on the withholding date.

After this vesting and tax withholding, Tatnall directly holds 23,044 shares, including 16,463 shares issuable upon vesting of restricted stock units that remain subject to forfeiture under the company’s 2012 Equity Incentive Plan.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Tatnall Christopher

Role EVP Global Customer Operations

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	907	$131.02	$119K

Holdings After Transaction: Common Stock — 23,044 shares (Direct, null)

Footnotes (1)

1. This forfeiture of shares for tax withholding purposes relates to the vesting on April 18, 2026 of service vesting restricted stock units granted to the executive in April 2022. 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. Represents the closing price of the Company's common stock on the date of the tax withholding. Of the shares held after this vesting on April 18, 2026, 16,463 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.

Key Figures

Tax-withheld shares: 907 shares Withholding share price: $131.02 per share Shares held after transaction: 23,044 shares +1 more

4 metrics

Tax-withheld shares 907 shares Shares withheld for tax obligations on RSU vesting

Withholding share price $131.02 per share Closing price on tax withholding date

Shares held after transaction 23,044 shares Direct holdings after April 18, 2026 vesting and withholding

Unvested RSU-linked shares 16,463 shares Issuable upon future RSU vesting, subject to forfeiture

Key Terms

restricted stock units, tax withholding, Equity Incentive Plan, closing price

4 terms

restricted stock units financial

"relates to the vesting on April 18, 2026 of service vesting 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.

tax withholding financial

"forfeiture of shares for tax withholding purposes relates to the vesting"

Tax withholding is the practice of taking a portion of a payment—such as wages, dividends, or sale proceeds—before it reaches the recipient and sending that portion to the tax authority as an advance on the recipient’s eventual tax bill. For investors it matters because withholding reduces immediate cash received and affects after‑tax returns, estimated tax payments, and whether you may owe more or receive a refund when taxes are finally calculated, like having a small automatic savings set aside for your tax bill.

Equity Incentive Plan financial

"granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture"

An equity incentive plan is a program that gives employees, executives or directors the right to receive company stock or options to buy stock as part of their pay. Think of it as offering slices of future company profit to motivate people to boost long‑term performance; for investors it matters because it can align employee goals with shareholder value but also increases the number of shares outstanding, which can dilute existing ownership.

closing price financial

"Represents the closing price of the Company's common stock on the date of the tax withholding"

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^*

Tatnall Christopher

(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 Global Customer Operations

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/20/2026

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	04/20/2026		F(1)		907	D	$131.02(2)	23,044(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 April 18, 2026 of service vesting restricted stock units granted to the executive in April 2022. 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.

2. Represents the closing price of the Company's common stock on the date of the tax withholding.

3. Of the shares held after this vesting on April 18, 2026, 16,463 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	04/21/2026
	** 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 Christopher Tatnall?

Axcelis reported that executive Christopher Tatnall had 907 shares of common stock withheld to cover taxes on vested restricted stock units. This was a tax-withholding disposition, not an open-market sale, tied to RSU vesting in April 2026.

At what price were Christopher Tatnall’s Axcelis (ACLS) shares withheld for taxes?

The 907 shares withheld for Christopher Tatnall’s tax obligations were valued at $131.02 per share. This amount represents the closing price of Axcelis Technologies’ common stock on the date the tax withholding occurred, as specified in the filing footnotes.

How many Axcelis (ACLS) shares does Christopher Tatnall hold after this Form 4 transaction?

Following the tax-withholding disposition, Christopher Tatnall holds 23,044 Axcelis common shares. This total includes his remaining directly held stock after 907 shares were withheld to satisfy tax obligations related to restricted stock unit vesting in April 2026.

What restricted stock units does Christopher Tatnall still have with Axcelis (ACLS)?

After the April 2026 vesting, 16,463 shares are still issuable to Christopher Tatnall upon vesting of restricted stock units under the 2012 Equity Incentive Plan. These units are subject to forfeiture and include RSUs earned at 112.5% of a 2025 performance grant.

Was Christopher Tatnall’s Axcelis (ACLS) Form 4 transaction an open-market sale?

No. The Form 4 describes a tax-withholding disposition of 907 shares, not an open-market sale. Shares were withheld to satisfy tax obligations arising from the vesting of restricted stock units granted in April 2022 to the executive.