Director David N. Watson Receives Dividend Equivalent Units from Restricted Stock Units

This Form 4 filing reports that David N. Watson, a director of Amkor Technology, Inc., received 2.5166 dividend equivalent units (DEUs) on June 23, 2026. These DEUs represent additional restricted stock units (RSUs) that accrued upon the payment of a dividend on time-vested RSUs originally granted to Watson on May 13, 2026. The DEUs are subject to the same provisions as the underlying RSUs. Following this acquisition, Watson's total holdings in Amkor Technology common stock equivalents increased to 2,615.5166 shares. The transaction was reported by Mark N. Rogers as attorney-in-fact for Watson on June 25, 2026. This filing represents a routine dividend reinvestment in director compensation rather than a market purchase or sale.