Eric Robert Taranto - 18 Feb 2025 Form 4 Insider Report for MKS INSTRUMENTS INC (MKSI)

Role: EVP & GM, VSD
Signature: /s/ M. Kathryn Rickards, attorney-in-fact
Issuer symbol: MKSI
Transactions as of: 18 Feb 2025
Net transactions value: -$182,459
Form type: 4
Filing time: 19 Feb 2025, 18:43:54 UTC
Previous filing: 11 Feb 2025
Next filing: 09 Feb 2026
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MKSI	Common Stock	Options Exercise		+1,119	+8.4%		14,421	18 Feb 2025	Direct	F1
transaction	MKSI	Common Stock	Options Exercise		+805	+5.6%		15,226	18 Feb 2025	Direct	F1
transaction	MKSI	Common Stock	Options Exercise		+1,764	+12%		16,990	18 Feb 2025	Direct	F1
transaction	MKSI	Common Stock	Options Exercise		+914	+5.4%		17,904	18 Feb 2025	Direct	F1
transaction	MKSI	Common Stock	Options Exercise		+348	+1.9%		18,252	18 Feb 2025	Direct	F1
transaction	MKSI	Common Stock	Options Exercise		+975	+5.3%		19,227	18 Feb 2025	Direct	F1
transaction	MKSI	Common Stock	Tax liability	$182,459	-1,760	-9.2%	$103.67	17,467	18 Feb 2025	Direct	F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	MKSI	Restricted Stock Unit	Award		+3,911	+35%		15,162	18 Feb 2025	Common Stock	3,911		Direct	F1, F3
transaction	MKSI	Restricted Stock Unit	Options Exercise		-1,119	-7.4%		14,044	18 Feb 2025	Common Stock	1,119		Direct	F1, F4
transaction	MKSI	Restricted Stock Unit	Options Exercise		-805	-5.7%		13,239	18 Feb 2025	Common Stock	805		Direct	F1, F5
transaction	MKSI	Restricted Stock Unit	Options Exercise		-1,764	-13%		11,475	18 Feb 2025	Common Stock	1,764		Direct	F1, F6
transaction	MKSI	Restricted Stock Unit	Options Exercise		-914	-8%		10,561	18 Feb 2025	Common Stock	914		Direct	F1, F7
transaction	MKSI	Restricted Stock Unit	Options Exercise		-348	-3.3%		10,213	18 Feb 2025	Common Stock	348		Direct	F1, F8
transaction	MKSI	Restricted Stock Unit	Options Exercise		-975	-9.5%		9,238	18 Feb 2025	Common Stock	975		Direct	F1, F9

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Instruments, Inc.
F2	These shares were withheld by MKS Instruments, 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 three equal annual installments commencing on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.
F4	These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2023, and thereafter vest in three equal annual installments beginning on February 15, 2023, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.
F5	These RSUs vest in three equal annual installments commencing on February 15, 2023, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.
F6	These RSUs were subject to performance criteria, the achievement of which was determined on February 5, 2024, and thereafter vest in three equal annual installments beginning on February 15, 2024, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.
F7	These RSUs vest in three equal annual installments commencing on February 15, 2024, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.
F8	These RSUs were subject to performance criteria, the achievement of which was determined on February 10, 2025, and thereafter vest in three equal annual installments beginning on February 15, 2025, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.
F9	These RSUs vest in three equal annual installments commencing on February 15, 2025, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.