MKSI Form 144: Notice for 8,810 vested shares

Rhea-AI Filing Summary

MKSI: Notice of proposed sale under Section 144 related to recently vested restricted shares

The filing lists restricted stock vesting entries for 3,143 shares on 02/15/2026 and 5,667 shares on 11/15/2025

The filing shows a broker entry for Fidelity Brokerage Services LLC and a date of 05/22/2026. The document records securities to be sold associated with compensation vesting; timing and exact sale mechanics are not detailed in the excerpt.

Insights

Securities Compliance Analyst

Form 144 lists planned resale of vested restricted shares by an insider or affiliate.

The excerpt shows two restricted stock vesting entries: 3,143 shares vested on 02/15/2026 and 5,667 shares vested on 11/15/2025

Section 144 notices permit resale of restricted or control securities under certain conditions; this filing notifies the broker and regulator but does not confirm execution details or proceeds.

Key Figures

Restricted shares vesting: 3,143 shares Restricted shares vesting: 5,667 shares Form filing date: 05/22/2026

3 metrics

Restricted shares vesting 3,143 shares Vesting date <date>02/15/2026</date>

Restricted shares vesting 5,667 shares Vesting date <date>11/15/2025</date>

Form filing date 05/22/2026 Broker and filing date listed alongside NASDAQ

Key Terms

Restricted Stock Vesting, Form 144, Compensation Common

3 terms

Restricted Stock Vesting regulatory

"Restricted Stock Vesting | Issuer | 3143 | 02/15/2026"

Restricted stock vesting is the timetable and conditions under which shares granted to employees or insiders become fully owned and can be sold, typically requiring continued work or meeting performance goals. It matters to investors because large blocks of shares can become tradable at once, which can change share supply and price, and because vesting aligns insiders’ incentives with the company’s long‑term performance—think of it like a timed unlock that both rewards and locks in key people.

Form 144 regulatory

"144: Securities To Be Sold"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Compensation Common financial

"Compensation Common | 11/15/2025 | Restricted Stock Vesting"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does MKSI's Form 144 disclose?

The Form 144 discloses planned resale related to vested restricted stock. It lists 3,143 shares vesting on 02/15/2026 and 5,667 shares vesting on 11/15/2025, and names Fidelity Brokerage Services LLC as the broker.

Does the filing mean the shares were sold?

No. The Form 144 is a notice of intent to sell restricted or control securities. The excerpt shows vesting and broker information but does not provide confirmation of completed sales or sale proceeds.

Who is the broker listed on the MKSI Form 144?

The broker listed is Fidelity Brokerage Services LLC at 900 Salem Street, Smithfield, RI. The filing associates the broker with the resale notice dated 05/22/2026 in the provided excerpt.

What are the dates tied to the restricted stock entries?

The restricted stock vesting dates shown are 11/15/2025 for 5,667 shares and 02/15/2026 for 3,143 shares. These dates are listed as the vesting/compensation dates in the excerpt.

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

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Accepted by SEC EDGAR 05/22/2026 - 12:13 PM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001859332
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	MKS INC
SEC File Number	000-23621
Address of Issuer	2 TECH DRIVE ANDOVER MASSACHUSETTS 01810
Phone	978-645-5500
Name of Person for Whose Account the Securities are To Be Sold	Mayampurath Ramakumar
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Fidelity Brokerage Services LLC 900 Salem Street Smithfield RI 02917	8810	2779378.80	67544129	05/22/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	02/15/2026	Restricted Stock Vesting	Issuer			3143	02/15/2026	Compensation
Common	11/15/2025	Restricted Stock Vesting	Issuer			5667	11/15/2025	Compensation

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Nothing to Report

144: Remarks and Signature

Remarks
Date of Notice	05/22/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	02/20/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Jared Cook, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Ram Mayampurath
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)