Kathleen Flaherty Burke - 17 Feb 2026 Form 4 Insider Report for MKS INC (MKSI)

Role
EVP, GC & Secretary
Signature
/s/ M. Kathryn Rickards, attorney-in-fact
Issuer symbol
MKSI
Transactions as of
17 Feb 2026
Net transactions value
-$1,386,563
Form type
4
Filing time
18 Feb 2026, 16:55:50 UTC
Previous filing
09 Feb 2026
Next filing
23 Feb 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Burke Kathleen Flaherty EVP, GC & Secretary C/O MKS INC., 2 TECH DRIVE, ANDOVER /s/ M. Kathryn Rickards, attorney-in-fact 18 Feb 2026 0001775435

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MKSI Common Stock Options Exercise +3,451 +6.7% 54,611 17 Feb 2026 Direct F1
transaction MKSI Common Stock Options Exercise +1,788 +3.3% 56,399 17 Feb 2026 Direct F1
transaction MKSI Common Stock Options Exercise +563 +1% 56,961 17 Feb 2026 Direct F1
transaction MKSI Common Stock Options Exercise +1,576 +2.8% 58,537 17 Feb 2026 Direct F1
transaction MKSI Common Stock Options Exercise +2,336 +4% 60,873 17 Feb 2026 Direct F1
transaction MKSI Common Stock Options Exercise +2,493 +4.1% 63,366 17 Feb 2026 Direct F1
transaction MKSI Common Stock Tax liability $1,386,563 -5,318 -8.4% $260.74 58,048 17 Feb 2026 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 +3,328 +14% 27,335 17 Feb 2026 Common Stock 3,328 Direct F1, F3
transaction MKSI Restricted Stock Unit Options Exercise -3,451 -13% 23,884 17 Feb 2026 Common Stock 3,451 Direct F1, F4
transaction MKSI Restricted Stock Unit Options Exercise -1,788 -7.5% 22,097 17 Feb 2026 Common Stock 1,788 Direct F1, F5
transaction MKSI Restricted Stock Unit Options Exercise -563 -2.5% 21,534 17 Feb 2026 Common Stock 563 Direct F1, F6
transaction MKSI Restricted Stock Unit Options Exercise -1,576 -7.3% 19,958 17 Feb 2026 Common Stock 1,576 Direct F1, F7
transaction MKSI Restricted Stock Unit Options Exercise -2,336 -12% 17,622 17 Feb 2026 Common Stock 2,336 Direct F1, F8
transaction MKSI Restricted Stock Unit Options Exercise -2,493 -14% 15,129 17 Feb 2026 Common Stock 2,493 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 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 three equal annual installments commencing on February 15, 2027, 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 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.
F5 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.
F6 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.
F7 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.
F8 These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2026, and thereafter vest in three equal annual installments beginning 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.
F9 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.