BlackRock, Inc. Increases Stake in MKS Instruments Inc.

BlackRock, Inc. has filed a Schedule 13G/A amendment with the SEC, disclosing an increased ownership in MKS Instruments Inc. As of September 30, 2025, BlackRock beneficially owns 5,887,663 shares of MKS Instruments' common stock, representing an 8.8% ownership stake. This marks an increase of 271,425 shares from their previous filing. The filing indicates that BlackRock acquired these shares in the ordinary course of business and not with the intent to influence control of the issuer. The shares are held by various business units of BlackRock, and no single entity owns more than 5% of the total outstanding shares. The filing was signed by Spencer Fleming, Managing Director, on October 17, 2025.