InsiderTrades

Form 4 for MKSI MKS INC

Accepted 2025-11-04 00:00:00 ET · period of report 2025-10-31 · accession 0001049502-25-000035 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X Filed Traded Ticker Insider Title Type Price Qty Owned ΔOwn Value
DM 2025-11-04 2025-10-31 MKSI Lee John Tseng-Chung Pres, CEO, Dir M - OptEx — +2,003 147.6K +1% —
D 2025-11-04 2025-10-31 MKSI Lee John Tseng-Chung Pres, CEO, Dir F - Tax $143.71 -2,003 147.3K -1% -$287.9K
DM 2025-11-04 2025-10-31 MKSI Lee John Tseng-Chung Pres, CEO, Dir M - OptEx — -2,003 89.8K -2% —

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2025-10-31 M A 1,651 — 149,272.52 D — — (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.
2 Common Common Stock 2025-10-31 F D 2,003 $143.71 147,269.52 D — —
3 Common Common Stock 2025-10-31 M A 352 — 147,621.52 D — — (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.
4 Derivative Restricted Stock Unit 2025-10-31 M D 1,651 — 88,152.62 D — · — to — 1,651 Common Stock (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F4) Portion of 2025 RSU Award accelerated to satisfy FICA taxes.
5 Derivative Restricted Stock Unit 2025-10-31 M D 352 — 89,803.62 D — · — to — 352 Common Stock (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F3) Portion of 2024 RSU Award accelerated to satisfy FICA taxes.