John Edward Williams, Executive Vice President and General Manager of the Power Solutions Division at MKS Instruments (NASDAQ: MKSI), filed a Form 4 on August 4, 2026, disclosing the sale of 457 shares of common stock on August 3, 2026.

Key Highlights

  • Reporting person: John Edward Williams, EVP & GM, PSD at MKS Instruments
  • Transaction: 457 shares of common stock disposed of (transaction code S) on August 3, 2026
  • Sale price: $288.31 per share
  • Remaining holdings: 4,097.844 shares of common stock held directly following the transaction
  • 10b5-1 plan: The sale was effected pursuant to a Rule 10b5-1 trading plan adopted on March 5, 2026
  • Filing date: August 4, 2026, filed by one reporting person

MKS Instruments Officer Share Sale Details and Plan Context

According to the filing, John Edward Williams, who serves as Executive Vice President and General Manager of the Power Solutions Division (PSD) at MKS Instruments, disposed of 457 shares of the company's common stock on August 3, 2026, at a price of $288.31 per share. The transaction is recorded as a sale (code S) in Table I of the Form 4, covering non-derivative securities.

The filing notes that the transaction was carried out directly and that following the reported transaction, Williams beneficially owns 4,097.844 shares of MKS Instruments common stock on a direct basis. No derivative securities transactions were reported in Table II of the filing.

As disclosed in the filing's explanation of responses, "This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 5, 2026." The filing also indicates that the Form 4 was filed by one reporting person and was signed by James Kruger as attorney-in-fact on August 4, 2026. No amendment date is listed, indicating this is an original filing.

What Was Disclosed

The filing discloses a single open-market sale of 457 shares of MKS Instruments common stock by EVP John Edward Williams at $288.31 per share on August 3, 2026, conducted under a pre-established Rule 10b5-1 trading plan adopted March 5, 2026, leaving him with 4,097.844 shares held directly.