Key facts
- This page summarizes John Tseng-Chung Lee's Form 4 filing for MKS INC (MKSI).
- 14 reported transactions and 7 derivative rows are listed below.
- Accepted by SEC: 18 Feb 2026, 16:52.
John Tseng-Chung Lee - 17 Feb 2026 Form 4 Insider Report for MKS INC (MKSI)
- Reporting relationship
- President & CEO, Director
- Issuer ticker
- MKSI
- Reported as of
- 17 Feb 2026
- Net transaction value
- -$8,486,646
- SEC form
- 4
- Accepted by SEC
- 18 Feb 2026, 16:52:34 UTC
- Prior SEC filing
- 09 Feb 2026
- Next SEC filing
- 23 Feb 2026
- Source filing
- View source filing
- Reporting owner signature
- /s/ M. Kathryn Rickards, attorney-in-fact
Source evidence
Original filing metadata and source links for verification.
5 source fields
Reporting owner
1 detail
Key filing fact
John Tseng-Chung Lee filed Form 4 for MKS INC (MKSI) on 18 Feb 2026.
Change
- Previous filing in this sequence was filed on 09 Feb 2026.
- Current net transaction value: -$8,486,646.
Research use
- This tells you what this filing adds before you inspect full transaction and derivative tables.
- You can trace every row back to the original SEC filing document.
Evidence
Filed on Form 4
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
Reporting Owners (1)
CIK 0001414656
Primary reporting owner
Lee John Tseng-Chung
- Relationship
- President & CEO, Director
- Address
- C/O MKS INC., 2 TECH DRIVE, ANDOVER
- Signature
- /s/ M. Kathryn Rickards, attorney-in-fact
- Signature date
- 18 Feb 2026
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
MKSI
transaction
Common Stock
Options Exercise
- Transaction value
- Shares
- +22,088
- Change %
- +15%
- Price
- Shares after
- 169,443
- Date
- 17 Feb 2026
- Ownership
- Direct
- Footnotes
- F1
MKSI
transaction
Common Stock
Options Exercise
- Transaction value
- Shares
- +7,654
- Change %
- +4.5%
- Price
- Shares after
- 177,097
- Date
- 17 Feb 2026
- Ownership
- Direct
- Footnotes
- F1
MKSI
transaction
Common Stock
Options Exercise
- Transaction value
- Shares
- +3,859
- Change %
- +2.2%
- Price
- Shares after
- 180,956
- Date
- 17 Feb 2026
- Ownership
- Direct
- Footnotes
- F1
MKSI
transaction
Common Stock
Options Exercise
- Transaction value
- Shares
- +7,208
- Change %
- +4%
- Price
- Shares after
- 188,164
- Date
- 17 Feb 2026
- Ownership
- Direct
- Footnotes
- F1
MKSI
transaction
Common Stock
Options Exercise
- Transaction value
- Shares
- +16,989
- Change %
- +9%
- Price
- Shares after
- 205,153
- Date
- 17 Feb 2026
- Ownership
- Direct
- Footnotes
- F1
MKSI
transaction
Common Stock
Options Exercise
- Transaction value
- Shares
- +12,091
- Change %
- +5.9%
- Price
- Shares after
- 217,244
- Date
- 17 Feb 2026
- Ownership
- Direct
- Footnotes
- F1
MKSI
transaction
Common Stock
Tax liability
- Transaction value
- $8,486,646
- Shares
- -32,548
- Change %
- -15%
- Price
- $260.74
- Shares after
- 184,696
- Date
- 17 Feb 2026
- Ownership
- Direct
- Footnotes
- F2
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
MKSI
transaction
Derivative
Restricted Stock Unit
Award
- Transaction value
- Shares
- +15,593
- Change %
- +11%
- Price
- Shares after
- 154,717
- Date
- 17 Feb 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 15,593
- Exercise price
- Footnotes
- F1, F3
MKSI
transaction
Derivative
Restricted Stock Unit
Options Exercise
- Transaction value
- Shares
- -22,088
- Change %
- -14%
- Price
- Shares after
- 132,629
- Date
- 17 Feb 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 22,088
- Exercise price
- Footnotes
- F1, F4
MKSI
transaction
Derivative
Restricted Stock Unit
Options Exercise
- Transaction value
- Shares
- -7,654
- Change %
- -5.8%
- Price
- Shares after
- 124,976
- Date
- 17 Feb 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 7,654
- Exercise price
- Footnotes
- F1, F5
MKSI
transaction
Derivative
Restricted Stock Unit
Options Exercise
- Transaction value
- Shares
- -3,859
- Change %
- -3.1%
- Price
- Shares after
- 121,117
- Date
- 17 Feb 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 3,859
- Exercise price
- Footnotes
- F1, F6
MKSI
transaction
Derivative
Restricted Stock Unit
Options Exercise
- Transaction value
- Shares
- -7,208
- Change %
- -6%
- Price
- Shares after
- 113,909
- Date
- 17 Feb 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 7,208
- Exercise price
- Footnotes
- F1, F7
MKSI
transaction
Derivative
Restricted Stock Unit
Options Exercise
- Transaction value
- Shares
- -16,989
- Change %
- -15%
- Price
- Shares after
- 96,919
- Date
- 17 Feb 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 16,989
- Exercise price
- Footnotes
- F1, F8
MKSI
transaction
Derivative
Restricted Stock Unit
Options Exercise
- Transaction value
- Shares
- -12,091
- Change %
- -12%
- Price
- Shares after
- 84,828
- Date
- 17 Feb 2026
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 12,091
- Exercise price
- Footnotes
- F1, F9
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 9 footnotes
Footnote F1
Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.
Footnote 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.
Footnote 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.
Footnote 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.
Footnote 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.
Footnote 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.
Footnote 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.
Footnote 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.
Footnote 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.