TTM Technologies, Inc.

Item 8.01 - Other Events. On October 19, 2026, TTM Technologies, Inc. (the “Company”) announced that it had entered into a definitive agreement to acquire (the “Proposed Acquisition”) the Ophir® Optics business (“Ophir Optics”) from MKS Inc. for approximately $650 million in an all-cash transaction, subject to customary closing adjustments (the “Press Release”). The Proposed Acquisition does not include the Ophir Instruments laser characterization business of MKS Inc., which operates separately from Ophir Optics, or the sale of the Ophir brand. The Proposed Acquisition is expected to close in the second quarter of 2027 and is subject to customary closing conditions, including certain regulatory approvals. A copy of the Press Release announcing the Proposed Acquisition is attached to this Current Report on Form 8-K (this “Report”) as Exhibit 99.1 and is incorporated herein by reference. Cautionary Note Regarding Forward-Looking Statements This Report, including Exhibit 99.1, contains forward-looking statements that relate to future events, including the receipt of required regulatory approvals in connection with the Proposed Acquisition. The Company cautions you that such statements are simply predictions and actual events or results may differ materially. These statements reflect the Company’s current expectations, and the Company does not undertake to update or revise these forward-looking statements, even if experience or future changes make it clear that any projected results expressed or implied in this Report or other Company statements will not be realized. The statements also involve risks and uncertainties, many of which are beyond the Company’s control, which could cause actual results to differ materially from the forward-looking statements. For a description of additional factors that may cause the Company’s actual events or results to differ from any forward-looking statements, please review the information set forth in the “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” sections of the Company’s public reports filed with the Securities and Exchange Commission.