AEIS: Material agreement · New financial obligation · Unregistered securities sale

Item 1.01. Entry into a Material Definitive Agreement. On May 18, 2026, Advanced Energy Industries, Inc. (the “Company”) completed its previously announced private unregistered offering of $1.15 billion aggregate principal amount of its 0% Convertible Senior Notes due 2031 (the “Notes”), which amount includes the full exercise of the initial purchasers’ option to purchase up to $150.0 million aggregate principal amount of additional Notes. Indenture and Notes The Notes were issued under an Indenture (the “Indenture”), dated as of May 18, 2026, by and between the Company and U.S. Bank Trust Company, National Association, as trustee (the “Trustee”). The Indenture provides, among other things, that the Notes will not bear regular interest, and the principal amount of the notes will not accrete. The Notes will mature on May 15, 2031, unless earlier repurchased or redeemed by the Company or converted pursuant to their terms. The Company received net proceeds from the offering of the Notes of approximately $1,128.1 million, after deducting the initial purchasers’ discounts and after deducting offering expenses payable by the Company. The Company used $69.0 million of the net proceeds from the offering to pay the cost of the Capped Call Confirmations entered into in connection with the offering, as described below. In addition, the Company paid approximately $442.4 million of the net proceeds from the offering and issued approximately 1.98 million shares of the Company’s common stock, par value $0.001 per share (“Common Stock”), collectively, in exchange for approximately $438.3 million aggregate principal amount of its previously issued 2.50% Convertible Senior Notes due 2028 (the “2028 Convertible Notes”), as described below. The Company intends to use the remainder of the n