MKSI

SEC source: 0001127602-21-006352 · form4.xml · derivative · entry 9

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,561.907

Underlying: Common Stock · 1,071.322 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F4 · derivative.exercise_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 28, 2019, and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 28, 2019, and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006352 · form4.xml · derivative · entry 8

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,633.229

Underlying: Common Stock · 3,048.78 shares

Expires not disclosed

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

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

F3 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2022, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2022, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006352 · form4.xml · nonDerivative · entry 7

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 39,430.224

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-21-006352 · form4.xml · nonDerivative · entry 6

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,655.224

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006352 · form4.xml · nonDerivative · entry 5

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 41,375.224

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006352 · form4.xml · nonDerivative · entry 4

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 39,531.224

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006352 · form4.xml · nonDerivative · entry 3

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,957.041

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006352 · form4.xml · nonDerivative · entry 2

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,666.211

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006352 · form4.xml · nonDerivative · entry 1

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,615.896

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 18

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 41,265.209

Underlying: Common Stock · 4,281 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F9 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F9 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 17

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,546.209

Underlying: Common Stock · 7,534 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F8 · derivative.exercise_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 25, 2021, and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F8 · derivative.expiration_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 25, 2021, and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 16

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,080.209

Underlying: Common Stock · 2,754.821 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F7 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F7 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 15

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 55,835.03

Underlying: Common Stock · 3,065.722 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F6 · derivative.exercise_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 27, 2020, and thereafter vest in three equal installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F6 · derivative.expiration_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 27, 2020, and thereafter vest in three equal installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 14

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,900.752

Underlying: Common Stock · 257.605 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F5 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F5 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 13

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 59,158.357

Underlying: Common Stock · 263.037 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F4 · derivative.exercise_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 28, 2019, and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 28, 2019, and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 12

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 59,421.394

Underlying: Common Stock · 1,950.585 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F5 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F5 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 11

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 61,371.979

Underlying: Common Stock · 1,989.597 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

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

F4 · derivative.exercise_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 28, 2019, and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs were subject to performance criteria, the achievement of which was determined on January 28, 2019, and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · derivative · entry 10

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 63,361.576

Underlying: Common Stock · 11,811.847 shares

Expires not disclosed

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

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

F3 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2022, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2022, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 9

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 34,001.021

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 8

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 43,805.021

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 7

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 39,524.021

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 6

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,990.021

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 5

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 29,235.2

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 4

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 26,169.478

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 3

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,911.873

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 2

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,648.836

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-006345 · form4.xml · nonDerivative · entry 1

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,698.251

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001127602-21-002530 · form4.xml · derivative · entry 1

Schreiner James Alan · CIK 0001797189 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,957.212

Underlying: Common Stock · 3,003.425 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-002525 · form4.xml · derivative · entry 1

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 21,584.449

Underlying: Common Stock · 5,532.625 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-002514 · form4.xml · derivative · entry 1

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,549.729

Underlying: Common Stock · 22,604.724 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-21-002520 · form4.xml · derivative · entry 1

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,494.354

Underlying: Common Stock · 11,997.893 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 25, 2021 and thereafter vest in three equal annual installments beginning on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-030957 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By The Gerald G. Colella 2018 Grantor Trust

Disclosed balance after: 0

F1 · ownership.nature: The reporting person's 2018 Grantor Trust terminated. On December 8, 2020, 24,934 shares in this trust were transferred to trusts for the reporting person's beneficiaries and the remaining 15,866 shares were distributed to the reporting person and are reported in this Form 4 as indirectly owned by The Gerald G. Colella Living Trust.

SEC source: 0001127602-20-030683 · form4.xml · derivative · entry 5

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 30,496.461

Underlying: Common Stock · 277 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: Portion of 2020 RSU Award accelerated to satisfy FICA taxes.

F4 · derivative.expiration_date: Portion of 2020 RSU Award accelerated to satisfy FICA taxes.

SEC source: 0001127602-20-030683 · form4.xml · derivative · entry 4

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 30,773.461

Underlying: Common Stock · 249 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: Portion of 2019 RSU Award accelerated to satisfy FICA taxes.

F3 · derivative.expiration_date: Portion of 2019 RSU Award accelerated to satisfy FICA taxes.

SEC source: 0001127602-20-030683 · form4.xml · nonDerivative · entry 3

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,288.59

F2 · kind: Shares used to satisfy FICA taxes.

SEC source: 0001127602-20-030683 · form4.xml · nonDerivative · entry 2

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,814.59

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-030683 · form4.xml · nonDerivative · entry 1

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,537.59

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-030299 · form4.xml · nonDerivative · entry 1

Mora Elizabeth · CIK 0001548935 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,051.314

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-20-029947 · form4.xml · nonDerivative · entry 1

Moloney Jacqueline F · CIK 0001501968 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,076.49

SEC source: 0001127602-20-025285 · form4.xml · derivative · entry 3

Schreiner James Alan · CIK 0001797189 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,953.787

Underlying: Common Stock · 1,433 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on September 16, 2020, provided that if, in any vesting year, September 16th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on September 16, 2020, provided that if, in any vesting year, September 16th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-025285 · form4.xml · nonDerivative · entry 2

Schreiner James Alan · CIK 0001797189 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,012

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-20-025285 · form4.xml · nonDerivative · entry 1

Schreiner James Alan · CIK 0001797189 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,433

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-024613 · form4.xml · nonDerivative · entry 1

Mora Elizabeth · CIK 0001548935 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,501.314

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-20-022643 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By The Gerald G. Colella Living Trust

Disclosed balance after: 82,596

F1 · price: This transaction was executed in multiple trades at prices ranging from $128.00 to $128.73. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-20-022070 · form4.xml · nonDerivative · entry 4

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,169.423

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F4 · price: This transaction was executed in multiple trades at prices ranging from $125.68 to $126.51. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-20-022070 · form4.xml · nonDerivative · entry 3

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,609.423

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F3 · price: This transaction was executed in multiple trades at prices ranging from $124.52 to $125.46. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-20-022070 · form4.xml · nonDerivative · entry 2

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 22,102.423

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $123.32 to $123.79. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-20-022070 · form4.xml · nonDerivative · entry 1

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,164.423

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-20-021262 · form4.xml · nonDerivative · entry 1

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,169.423

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $116.00 to $117.78. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-20-021105 · form4.xml · derivative · entry 25

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 7,550.917 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: On January 1, 2020, Mr. Colella retired from the Company and pursuant to the terms of his RSU Agreement, these RSUs fully vested on that date but were not distributable until July 2, 2020 in accordance with Internal Revenue Code Section 409A.

F14 · derivative.exercise_date: These RSUs were awarded on February 15, 2019. These RSUs were scheduled to vest on February 15, 2022.

F4 · derivative.expiration_date: On January 1, 2020, Mr. Colella retired from the Company and pursuant to the terms of his RSU Agreement, these RSUs fully vested on that date but were not distributable until July 2, 2020 in accordance with Internal Revenue Code Section 409A.

F14 · derivative.expiration_date: These RSUs were awarded on February 15, 2019. These RSUs were scheduled to vest on February 15, 2022.