MKS INC — Director's Dealing 2025

Aug 18, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INC (MKSI)
CIK: 0001049502
Period of Report: 2025-08-15

Reporting Person: Williams John Edward (EVP & GM, PSD)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-08-15	Common Stock	M	947.285	—	Acquired	3948.099	Direct
2025-08-15	Common Stock	F	308	$104.73	Disposed	3640.099	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-08-15	Restricted Stock Unit	$	M	947.285	Disposed		Common Stock (947.285)	Direct

Footnotes

F1: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F2: These shares were withheld by MKS Inc. to satisfy the tax withholding obligations triggered by the vesting of RSUs and do not represent a discretionary trade by the reporting person.

F3: These RSUs vest in two equal annual installments commencing on August 15, 2024, provided that if, in any vesting year, August 15th is not a business day, such vesting shall occur on the next business day.