[Form 4] MKS Inc. Insider Trading Activity

Rhea-AI Filing Summary

MKS Inc. (MKSI) – Form 4 insider transaction

Director Jacqueline F. Moloney reported the sale of 300 common shares on 01 Aug 2025 at $92.10 each, realizing ≈$27.6 k in gross proceeds. The sale was carried out under a Rule 10b5-1 trading plan adopted on 10 Sep 2024, indicating it was pre-arranged rather than discretionary.

After the trade, Moloney directly owns 11,862.304 shares. No derivative securities were involved and her insider status remains “Director.”

The disposition equals <0.1 % of her reported stake and is insignificant versus MKSI’s ~67 m shares outstanding, suggesting limited market impact. Nonetheless, investors often monitor any insider selling; the 10b5-1 disclosure mitigates potential negative interpretation.

Positive

• Pre-planned Rule 10b5-1 trade enhances transparency and reduces information-asymmetry risk.
• Timely disclosure aligns with SEC requirements, supporting governance best practices.

Negative

• Insider sale, even small, can be interpreted by some investors as a marginally negative signal.

Insights

Equity Analyst

TL;DR – Small, pre-planned director sale; negligible impact.

The transaction involves only 300 shares, a trivial fraction of both the insider’s holdings and MKSI’s float. Execution under a disclosed 10b5-1 plan lowers informational risk, signalling routine portfolio management rather than insider pessimism. I view the filing as neutral for valuation and sentiment.

Corporate Governance Specialist

TL;DR – Governance compliant, transparent trade.

Use of a 10b5-1 plan and prompt Form 4 filing demonstrate adherence to best-practice disclosure standards. No red flags arise regarding compliance or potential conflicts. The minimal size provides no meaningful governance concern.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Moloney Jacqueline F

(Last) (First) (Middle)

C/O MKS INC.

2 TECH DRIVE

(Street)

ANDOVER MA 01810

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MKS INC [ MKSI ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/01/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/01/2025		S(1)		300	D	$92.1	11,862.304	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 10, 2024.

	/s/ M. Kathryn Rickards, attorney-in-fact	08/04/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

How many MKSI shares did Director Moloney sell?

She sold 300 common shares on 01 Aug 2025.

At what price were the MKSI shares sold?

The reported sale price was $92.10 per share.

How many MKSI shares does Moloney still own?

Following the sale she directly owns 11,862.304 shares.

Was the transaction part of a 10b5-1 plan?

Yes, it was executed under a Rule 10b5-1 plan adopted on 10 Sep 2024.

Does this filing affect MKSI’s share count materially?

No, 300 shares is immaterial versus MKSI’s roughly 67 million shares outstanding.