Gerald G. Colella - 27 May 2026 Form 4 Insider Report for MKS INC (MKSI)

Reporting relationship: Director
Issuer ticker: MKSI
Reported as of: 27 May 2026
Net transaction value: -$6,668,075
SEC form: 4
Accepted by SEC: 28 May 2026, 14:04:31 UTC
Prior SEC filing: 12 May 2026
Next SEC filing: 19 Aug 2026
Source filing: View source filing
Reporting owner signature: /s/ M. Kathryn Rickards, attorney-in-fact

Key filing fact

Gerald G. Colella filed Form 4 for MKS INC (MKSI) on 28 May 2026.

Key facts

This page summarizes Gerald G. Colella's Form 4 filing for MKS INC (MKSI).
7 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 28 May 2026, 14:04.

Change

Previous filing in this sequence was filed on 12 May 2026.
Current net transaction value: -$6,668,075.

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

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001256715 Primary reporting owner

COLELLA GERALD G

Relationship: Director
Address: C/O MKS INC., 2 TECH DRIVE, ANDOVER
Signature: /s/ M. Kathryn Rickards, attorney-in-fact
Signature date: 28 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

MKSI transaction

Common Stock

Sale

Transaction value: $153,298
Shares: -464
Change %: -1.2%
Price: $330.38
Shares after: 39,553
Date: 27 May 2026
Ownership: By The Gerald G. Colella 2019 Trust
Footnotes: F1, F2

MKSI transaction

Common Stock

Sale

Transaction value: $2,721,195
Shares: -8,210
Change %: -21%
Price: $331.45
Shares after: 31,343
Date: 27 May 2026
Ownership: By The Gerald G. Colella 2019 Trust
Footnotes: F1, F3

MKSI transaction

Common Stock

Sale

Transaction value: $1,619,034
Shares: -4,876
Change %: -16%
Price: $332.04
Shares after: 26,467
Date: 27 May 2026
Ownership: By The Gerald G. Colella 2019 Trust
Footnotes: F1, F4

MKSI transaction

Common Stock

Sale

Transaction value: $607,514
Shares: -1,811
Change %: -6.8%
Price: $335.46
Shares after: 24,656
Date: 27 May 2026
Ownership: By The Gerald G. Colella 2019 Trust
Footnotes: F1, F5

MKSI transaction

Common Stock

Sale

Transaction value: $547,219
Shares: -1,626
Change %: -6.6%
Price: $336.54
Shares after: 23,030
Date: 27 May 2026
Ownership: By The Gerald G. Colella 2019 Trust
Footnotes: F1, F6

MKSI transaction

Common Stock

Sale

Transaction value: $71,792
Shares: -213
Change %: -0.92%
Price: $337.05
Shares after: 22,817
Date: 27 May 2026
Ownership: By The Gerald G. Colella 2019 Trust
Footnotes: F1, F7

MKSI transaction

Common Stock

Sale

Transaction value: $948,024
Shares: -2,800
Change %: -12%
Price: $338.58
Shares after: 20,017
Date: 27 May 2026
Ownership: By The Gerald G. Colella 2019 Trust
Footnotes: F1

MKSI holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 8,999
Date: 27 May 2026
Ownership: Direct

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 7 footnotes

Footnote F1

This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 24, 2026.

Footnote F2

This transaction was executed in multiple trades at prices ranging from $329.90 to $330.90. 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.

Footnote F3

This transaction was executed in multiple trades at prices ranging from $330.95 to $331.90. 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.

Footnote F4

This transaction was executed in multiple trades at prices ranging from $331.98 to $332.44. 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.

Footnote F5

This transaction was executed in multiple trades at prices ranging from $334.60 to $335.55. 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.

Footnote F6

his transaction was executed in multiple trades at prices ranging from $335.82 to $336.82. 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.

Footnote F7

This transaction was executed in multiple trades at prices ranging from $337.00 to $337.73. 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.