Were the Axcelis (ACLS) insider share dispositions open-market sales?

The dispositions reported were not open-market sales. A total of 1,259 shares were forfeited at $155.18 per share solely to cover tax withholding obligations tied to the vesting of previously granted service-vesting restricted stock units from 2023, 2024, and 2025.

Axcelis Technologies (ACLS) EVP awarded RSUs and withholds shares for tax

Filing Impact

(Moderate)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

Axcelis Technologies EVP Christopher Tatnall reported routine equity compensation and related tax withholding transactions. On May 15, 2026, he received two awards of 3,504 shares each of restricted stock units under the 2012 Equity Incentive Plan. One grant is scheduled to vest in three equal parts on May 15, 2027, May 15, 2028, and May 15, 2029, assuming continued employment.

The other grant is performance-based, with shares earned between 0% and 200% of the granted units based on relative total shareholder return for the period from January 1, 2026 to December 31, 2028, vesting after performance is measured in 2029. The filing also shows dispositions of 1,259 shares at $155.18 per share to cover tax withholding on previously granted restricted stock units, which were not open-market sales.

Insider Trade Summary

5 transactions reported

Mixed 5 txns

Insider Tatnall Christopher

Role EVP Global Customer Operations

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	3,504	$0.00	--
Grant/Award	Common Stock	3,504	$0.00	--
Tax Withholding	Common Stock	744	$155.18	$115K
Tax Withholding	Common Stock	345	$155.18	$54K
Tax Withholding	Common Stock	170	$155.18	$26K

Holdings After Transaction: Common Stock — 26,548 shares (Direct, null)

Footnotes (1)

These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan on May 15, 2026. Assuming continuation of employment, these restricted stock units will vest as to one-third of the shares granted on each of May 15, 2027, May 15, 2028, and May 15, 2029. Of the shares held following this grant on May 15, 2026, 19,967 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture. These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan on May 15, 2026. In this grant, the executive may earn shares of common stock, ranging from zero to 200% of the granted units. The shares are earned based on the achievement of performance goals based on relative total shareholder return over a performance period of January 1, 2026 to December 31, 2028. Assuming continuation of employment, 100% of the earned shares will vest on measurement of performance in 2029. Unearned restricted stock units will forfeit at such time. Of the shares held after this grant on May 15, 2026, 23,471 shares were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture. This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2025. 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 common stock on the date of the tax withholding. Of the shares held after this vesting event on May 15, 2026, 21,934 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture. This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 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. Of the shares held after this vesting event on May 15, 2026, 21,221 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 forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2023. 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. Of the shares held after this vesting event on May 15, 2026, 20,871 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

Tax-withholding shares: 1,259 shares Tax-withholding price: $155.18 per share Time-based RSU grant: 3,504 shares +4 more

7 metrics

Tax-withholding shares 1,259 shares Shares forfeited for tax withholding on May 15, 2026

Tax-withholding price $155.18 per share Closing price used to value tax withholding shares

Time-based RSU grant 3,504 shares Service-vesting RSUs granted May 15, 2026

Performance RSU grant 3,504 shares Performance-based RSUs granted May 15, 2026

Performance payout range 0%–200% of units Earned based on relative total shareholder return

Performance period Jan 1, 2026–Dec 31, 2028 Measurement window for performance-based RSUs

Service RSU vesting dates May 15, 2027/2028/2029 Annual vesting schedule for time-based RSUs

Key Terms

restricted stock units, 2012 Equity Incentive Plan, relative total shareholder return, tax withholding, +1 more

5 terms

restricted stock units financial

"These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan"

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

"granted under the Company's 2012 Equity Incentive Plan on May 15, 2026"

relative total shareholder return financial

"performance goals based on relative total shareholder return over a performance period of January 1, 2026 to December 31, 2028"

Relative total shareholder return measures how much an investor’s gain from a company — including stock price changes and dividends — beats or lags a chosen benchmark or peer group over a set time. Think of it as a race: it shows whether the company outpaced rivals or the market, which helps investors and boards judge performance, compare returns fairly, and link results to pay or investment decisions.

tax withholding financial

"forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026"

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.

subject to forfeiture financial

"shares were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture"

Form 4 Insider Transactions: What Each Field Means →

05/19/2026 - 05:05 PM

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)
05/15/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/15/2026		A		3,504	A	$0⁽¹⁾	26,548⁽²⁾	D
Common Stock	05/15/2026		A		3,504	A	$0⁽³⁾	30,052⁽⁴⁾	D
Common Stock	05/15/2026		F		744	D⁽⁵⁾	$155.18⁽⁶⁾	29,308⁽⁷⁾	D
Common Stock	05/15/2026		F		345	D⁽⁸⁾	$155.18⁽⁶⁾	28,963⁽⁹⁾	D
Common Stock	05/15/2026		F		170	D⁽¹⁰⁾	$155.18⁽⁶⁾	28,793⁽¹¹⁾	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan on May 15, 2026. Assuming continuation of employment, these restricted stock units will vest as to one-third of the shares granted on each of May 15, 2027, May 15, 2028, and May 15, 2029.

2. Of the shares held following this grant on May 15, 2026, 19,967 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

3. These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan on May 15, 2026. In this grant, the executive may earn shares of common stock, ranging from zero to 200% of the granted units. The shares are earned based on the achievement of performance goals based on relative total shareholder return over a performance period of January 1, 2026 to December 31, 2028. Assuming continuation of employment, 100% of the earned shares will vest on measurement of performance in 2029. Unearned restricted stock units will forfeit at such time.

4. Of the shares held after this grant on May 15, 2026, 23,471 shares were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

5. This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2025. 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.

6. Represents the closing price of the common stock on the date of the tax withholding.

7. Of the shares held after this vesting event on May 15, 2026, 21,934 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture.

8. This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 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.

9. Of the shares held after this vesting event on May 15, 2026, 21,221 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture.

10. This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2023. 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.

11. Of the shares held after this vesting event on May 15, 2026, 20,871 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	05/19/2026
	** 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)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transactions did Axcelis (ACLS) EVP Christopher Tatnall report?

Christopher Tatnall reported equity compensation and tax-withholding transactions. He received two restricted stock unit grants of 3,504 shares each, and 1,259 shares were withheld at $155.18 per share to satisfy tax obligations on earlier restricted stock unit vestings.

How many Axcelis (ACLS) restricted stock units were granted to the EVP?

Tatnall received two restricted stock unit awards of 3,504 shares each. One is a time-based grant vesting in three annual installments, while the other is performance-based and can pay out between 0% and 200% of the granted units, depending on relative shareholder return.

How will the new Axcelis (ACLS) time-based RSUs vest for the EVP?

The time-based restricted stock units granted on May 15, 2026 vest in three equal installments. Assuming continued employment, one-third of the shares vest on May 15, 2027, another third on May 15, 2028, and the final third on May 15, 2029 under the 2012 Equity Incentive Plan.

What performance conditions apply to the Axcelis (ACLS) performance-based RSUs?

The performance-based restricted stock units are earned based on relative total shareholder return from January 1, 2026 to December 31, 2028. Depending on performance, Tatnall may earn between 0% and 200% of the granted units, with earned shares vesting after performance measurement in 2029.

How are Axcelis (ACLS) restricted stock units from prior grants treated after this filing?

Footnotes state that, after the May 15, 2026 vesting events and grants, tens of thousands of shares remain issuable upon future restricted stock unit vesting. These unvested units are subject to forfeiture under the company’s 2012 Equity Incentive Plan if conditions are not met.