Axcelis Technologies CEO Russell Low Sells Shares for Tax Withholding

This Form 4 filing reports that Russell Low, President and CEO of Axcelis Technologies, disposed of 711 shares of common stock on May 18, 2026, at a price of $146.24 per share. The transaction was coded as 'F' (Forfeiture), representing shares withheld to cover tax obligations related to the vesting of restricted stock units granted in May 2022. The shares vested on May 16, 2026, and the company withheld shares equal to the executive's tax withholding obligation. Following this transaction, Low holds 154,900 shares, of which 106,691 are subject to forfeiture as they represent unvested restricted stock units under the company's 2012 Equity Incentive Plan. The filing was signed by attorney-in-fact Eileen J. Evans on May 20, 2026.