Lee John Tseng-Chung 4

What Happened

John Tseng-Chung Lee, President, CEO and a director of MKS INC (MKSI), reported an open-market sale of 10,000 shares on 2026-05-22 at $315.48 per share, generating proceeds of $3,154,800. This was a sale (not a purchase), and the filing notes the trade was made under a pre-established Rule 10b5‑1 trading plan.

Key Details

• Transaction date: 2026-05-22
• Transaction type: Open-market sale (S)
• Shares sold: 10,000 at $315.48 per share
• Gross proceeds: $3,154,800
• Footnote: Transaction effected pursuant to a Rule 10b5‑1 trading plan adopted by the reporting person on 2026-02-20.
• Shares owned after transaction: Not specified in the provided filing excerpt.
• Filing date: 2026-05-26 — appears to be timely (filed within the Form 4 reporting window given the 5/22 transaction and the 5/25 federal holiday).

Context

Sales executed under a 10b5‑1 plan are pre-planned and are generally viewed as routine liquidity events rather than a direct signal of the insider’s current view on the company. For retail investors, purchases often carry more informational weight than routine sales, but tracking insider activity alongside other signals can still be useful.