MKS Inc (MKSI) EVP Burke sells 4,254 shares in open market trade

Rhea-AI Filing Summary

MKS Inc executive Kathleen Flaherty Burke, EVP, GC & Secretary, reported an open-market sale of 4,254 shares of Common Stock at $250.00 per share on February 20, 2026. After this sale, she directly owns 53,794.485 shares of MKS Inc common stock.

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

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

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^*

Burke Kathleen Flaherty

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, GC & Secretary

3. Date of Earliest Transaction (Month/Day/Year)
02/20/2026

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	02/20/2026		S		4,254	D	$250	53,794.485	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:

	/s/ M. Kathryn Rickards, attorney-in-fact	02/23/2026
	** 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

What insider transaction did MKSI executive Kathleen Flaherty Burke report?

Kathleen Flaherty Burke reported selling 4,254 shares of MKS Inc common stock in an open-market transaction at $250.00 per share. The Form 4 shows this as a sale of non-derivative common stock directly owned by her.

What is Kathleen Flaherty Burke’s remaining MKSI share ownership after this sale?

After the reported sale, Kathleen Flaherty Burke directly owns 53,794.485 shares of MKS Inc common stock. This figure reflects her direct ownership immediately following the open-market sale disclosed in the Form 4 filing.

On what date did the MKSI insider stock sale by Kathleen Flaherty Burke occur?

The insider stock sale occurred on February 20, 2026. On that date, Kathleen Flaherty Burke executed an open-market sale of 4,254 shares of MKS Inc common stock at a reported price of $250.00 per share.

What transaction code is used for Kathleen Flaherty Burke’s MKSI stock sale?

The transaction is coded “S,” indicating a sale in an open market or private transaction. The Form 4 describes this as an open-market sale of non-derivative common stock directly owned by Kathleen Flaherty Burke.

Is Kathleen Flaherty Burke’s MKSI stock transaction direct or indirect ownership?

The Form 4 reports the transaction under direct ownership, marked with code “D.” This means the 4,254 shares sold and the 53,794.485 shares remaining are held directly by Kathleen Flaherty Burke, not through an intermediary entity.