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MKS EVP sells 4,355 shares at $319.935

MKS INC executive Kathleen Flaherty Burke reported an open-market sale of 4,355 shares of Common Stock.

Filing Impact
(Very High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

MKS INC executive Kathleen Flaherty Burke reported an open-market sale of 4,355 shares of Common Stock. The transaction occurred on May 11, 2026 at a weighted average price of $319.935 per share, executed in multiple trades between $319.715 and $320.670.

After this sale, Burke directly holds 49,439.485 shares of MKS INC common stock. The filing notes she can provide full trade details, including the number of shares and prices for each individual execution, upon request.

Positive

  • None.

Negative

  • None.

Insights

MKS INC’s EVP executed a routine-sized open-market stock sale.

The EVP, GC & Secretary, Kathleen Flaherty Burke, sold 4,355 shares of MKS INC common stock in an open-market transaction at a weighted average price of $319.935 per share on May 11, 2026. This is classified as a straightforward open-market sale.

Following the sale, she directly holds 49,439.485 shares, so the transaction represents a relatively small portion of her disclosed equity position. No derivative exercises, tax withholdings, or trading-plan references appear in the excerpt, suggesting this is a single-step liquidity event rather than part of a complex option exercise pattern.

Insider Burke Kathleen Flaherty
Role EVP, GC & Secretary
Sold 4,355 shs ($1.39M)
Type Security Shares Price Value
Sale Common Stock 4,355 $319.935 $1.39M
Holdings After Transaction: Common Stock — 49,439.485 shares (Direct)
Footnotes (1)
  1. F1. This transaction was executed in multiple trades at prices ranging from $319.715 to $320.670. 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.
Shares sold 4,355 shares Open-market sale on May 11, 2026
Weighted average sale price $319.935 per share Common Stock sale on May 11, 2026
Price range of trades $319.715–$320.670 per share Multiple executions within one sale transaction
Shares owned after transaction 49,439.485 shares Direct holdings following May 11, 2026 sale
Net buy/sell shares -4,355 shares Net-sell direction in transaction summary
open-market sale financial
"The transaction is described as an open-market sale of common stock."
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
weighted average sale price financial
"The price reported above reflects the weighted average sale price."
Form 4 regulatory
"The transaction is disclosed on a Form 4 insider trading report."
Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.
Common Stock financial
"The security title reported for this transaction is Common Stock."
Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

FAQ

What insider transaction did MKS INC (MKSI) report for Kathleen Flaherty Burke?
MKS INC reported that EVP, GC & Secretary Kathleen Flaherty Burke sold 4,355 shares of common stock. The transaction was an open-market sale executed on May 11, 2026, and is disclosed on a Form 4 insider trading report for transparency to investors.

At what price did the MKS INC (MKSI) executive sell shares on May 11, 2026?
The reported weighted average sale price was $319.935 per share. The filing notes the transaction occurred in multiple trades, with individual prices ranging from $319.715 to $320.670, and the executive offers to provide full trade details to interested parties upon request.

How many MKS INC (MKSI) shares does Kathleen Flaherty Burke hold after this Form 4 sale?
After selling 4,355 shares, Kathleen Flaherty Burke directly holds 49,439.485 MKS INC common shares. This remaining stake, disclosed in the Form 4, helps investors gauge the size of the transaction relative to her ongoing equity ownership in the company.

What type of transaction is reported in this MKS INC (MKSI) Form 4 filing?
The Form 4 reports an open-market sale of MKS INC common stock. It is coded as transaction type “S”, described as a sale in an open market or private transaction, indicating the executive disposed of shares rather than exercising options or receiving an equity grant.

Were the MKS INC (MKSI) insider trades on May 11, 2026 executed in multiple lots?
Yes. The filing states the sale was executed in multiple trades between $319.715 and $320.670 per share. The reported $319.935 price is a weighted average, and the insider undertakes to provide detailed trade-by-trade information upon request.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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SEC Form 4
FORM 4UNITED 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).
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 MASSACHUSETTS 01810
(City)(State)(Zip)
UNITED STATES
(Country)		2. Issuer Name and Ticker or Trading Symbol
MKS INC [ MKSI ] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
EVP, GC & Secretary
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/11/2026		6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

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)
CodeVAmount(A) or (D)Price
Common Stock05/11/2026S4,355D$319.935(1)49,439.485D
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
1. This transaction was executed in multiple trades at prices ranging from $319.715 to $320.670. 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.
/s/ M. Kathryn Rickards, attorney-in-fact05/12/2026
** Signature of Reporting PersonDate
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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR