Politan supports Masimo (NASDAQ: MASI) merger with Danaher, holding 6.2% stake

Rhea-AI Filing Summary

Masimo Corporation’s major shareholder Politan Capital has updated its ownership filing after a merger announcement with Danaher. Politan and related entities report beneficial ownership of 4,590,873 Masimo common shares, representing 6.2% of the company, based on 74,218,782 shares outstanding as of February 13, 2026.

Masimo agreed to a merger in which a Danaher subsidiary will combine with Masimo, leaving Masimo as a wholly owned Danaher subsidiary. In connection with this, Politan entered into a Voting and Support Agreement committing to vote its Masimo shares in favor of adopting the merger agreement and approving the merger, and agreeing to customary transfer restrictions.

The filing notes that no Masimo share transactions were made by the reporting persons in the past 60 days and that a portion of their holdings is pledged under a standard margin loan facility.

Insights

Event-driven equity analyst

Politan’s 13D amendment confirms a 6.2% stake and formal support for Masimo’s merger with Danaher.

The filing shows Politan Capital and related entities beneficially owning 4,590,873 Masimo shares, or 6.2% of the common stock, calculated on 74,218,782 shares outstanding as of February 13, 2026. This reflects a sizable, but minority, position in the company.

It also discloses that Masimo signed a merger agreement with Danaher, under which a Danaher subsidiary will merge with Masimo, leaving Masimo as a wholly owned Danaher subsidiary. Politan entered into a Voting and Support Agreement committing its shares to vote in favor of adopting the merger agreement and the merger, and accepting customary transfer restrictions.

The document states that the reporting persons have not traded Masimo stock in the prior 60 days and that part of their holdings backs a standard margin loan facility. Subsequent company filings around the merger’s progress and closing conditions will clarify timing and final outcomes.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 16)

MASIMO CORP

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

574795100

(CUSIP Number)

Quentin Koffey
Politan Capital Management LP, 106 West 56th Street, 10th Floor
New York, NY, 10019
646-690-2830

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

02/16/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 574795100

1

Name of reporting person

Politan Capital Management LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 4,586,630.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 4,586,630.00

11

Aggregate amount beneficially owned by each reporting person

4,586,630.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.2 %

14

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13D

CUSIP No. 574795100

1

Name of reporting person

Politan Capital Management GP LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 4,586,630.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 4,586,630.00

11

Aggregate amount beneficially owned by each reporting person

4,586,630.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.2 %

14

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13D

CUSIP No. 574795100

1

Name of reporting person

Politan Capital Partners GP LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 4,586,630.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 4,586,630.00

11

Aggregate amount beneficially owned by each reporting person

4,586,630.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.2 %

14

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13D

CUSIP No. 574795100

1

Name of reporting person

Quentin Koffey

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 4,243.00
8	Shared Voting Power 4,586,630.00
9	Sole Dispositive Power 4,243.00
10	Shared Dispositive Power 4,586,630.00

11

Aggregate amount beneficially owned by each reporting person

4,590,873.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

6.2 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

The amounts in rows 7, 9 and 11 include 4,243 restricted share units granted to Mr. Koffey in connection with his service as a director on the Board, 3,018 of which have vested as of the date hereof and 1,225 of which are scheduled to vest on the earlier of the first anniversary of the grant date or the date of the Issuer's 2026 annual meeting of stockholders.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.001 per share
(b)	Name of Issuer: MASIMO CORP
(c)	Address of Issuer's Principal Executive Offices: 52 Discovery, Irvine, CALIFORNIA , 92618.
Item 1 Comment: This Amendment No. 16 to Schedule 13D (this "Amendment No. 16") amends and supplements the Schedule 13D filed on August 16, 2022 (as amended and supplemented through the date of this Amendment No. 16, collectively, the "Schedule 13D") by the Reporting Persons, relating to the common stock, par value $0.001 per share, of Masimo Corporation, a Delaware corporation (the "Issuer"). Capitalized terms not defined in this Amendment No. 16 shall have the meaning ascribed to them in the Schedule 13D.
Item 4.	Purpose of Transaction
	Item 4 is hereby amended and supplemented as follows: On February 16, 2026, the Issuer entered into an Agreement and Plan of Merger (the "Merger Agreement") with Danaher Corporation, a Delaware corporation ("Parent"), and Mobius Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent ("Merger Sub"), pursuant to which, among other things, Merger Sub will merge with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent. On February 16, 2026, in connection with the execution of the Merger Agreement, Politan entered into a Voting and Support Agreement (the "Voting Agreement") with Parent, Merger Sub and the Issuer, pursuant to which and on the terms and subject to the conditions thereof, among other things, Politan has agreed to customary transfer restrictions and to vote its shares of Common Stock in favor of the adoption of the Merger Agreement and the approval of the Merger. The foregoing summary of the Voting Agreement is not complete and is qualified in its entirety by reference to the full text of the Voting Agreement, a copy of which is included as Exhibit 99.18 to this Schedule 13D by reference to Exhibit 10.1 to the Issuer's Current Report on Form 8-K, filed with the SEC on February 17, 2026, and is incorporated by reference herein.
Item 5.	Interest in Securities of the Issuer
(a)	Item 5(a) is hereby amended and restated in its entirety as follows: See rows (11) and (13) of the cover pages to this Schedule 13D for the aggregate number of shares of Common Stock and percentages of the shares of Common Stock beneficially owned by each Reporting Person. The percentages used in this Schedule 13D are calculated based upon 74,218,782 shares of Common Stock outstanding as of February 13, 2026, as disclosed in the Merger Agreement, which was included as Exhibit 2.1 to the Issuer's Current Report on Form 8-K, filed with the SEC on February 17, 2026.
(b)	Item 5(b) is hereby amended and restated in its entirety as follows: See rows (7) through (10) of the cover pages to this Schedule 13D for the number of shares of Common Stock as to which each Reporting Person has the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition.
(c)	Item 5(c) is hereby amended and restated in its entirety as follows: No transactions in the shares of Common Stock have been effected by the Reporting Persons during the past sixty (60) days.
Item 6.	Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer
	Item 6 is hereby amended and restated as follows: The information provided or incorporated by reference in Item 4 is hereby incorporated by reference herein. A certain portion of the shares of Common Stock beneficially owned by the Reporting Persons is held in one or more collateral accounts subject to a standard margin loan facility between Politan Master Fund and unaffiliated financial lender parties. Except as set forth herein, the Reporting Persons have no contracts, arrangements, understandings or relationships (legal or otherwise) with respect to any securities of the Issuer, including any class of the Issuer's securities used as a reference security, in connection with any of the following: call options, put options, security-based swaps or any other derivative securities, transfer or voting of any of the securities, finder's fees, joint ventures, loan or option arrangements, guarantees of profits, division of profits or loss, or the giving or withholding of proxies.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 99.18: Voting and Support Agreement, dated as of February 16, 2026 (incorporated by reference to Exhibit 10.1 to the Issuer's Current Report on Form 8-K, filed with the SEC on February 17, 2026).

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Politan Capital Management LP

Signature:	/s/ Quentin Koffey
Name/Title:	Quentin Koffey, Managing Member
Date:	02/17/2026

Politan Capital Management GP LLC

Signature:	/s/ Quentin Koffey
Name/Title:	Quentin Koffey, Managing Member
Date:	02/17/2026

Politan Capital Partners GP LLC

Signature:	/s/ Quentin Koffey
Name/Title:	Quentin Koffey, Managing Member
Date:	02/17/2026

Quentin Koffey

Signature:	/s/ Quentin Koffey
Name/Title:	Quentin Koffey
Date:	02/17/2026

FAQ

How many Masimo (MASI) shares does Politan Capital report owning in this 13D/A?

Politan Capital and related reporting persons disclose beneficial ownership of 4,590,873 Masimo common shares. This corresponds to 6.2% of Masimo’s outstanding stock, calculated using 74,218,782 shares outstanding as of February 13, 2026, as referenced in the merger agreement.

What percentage of Masimo (MASI) does Politan’s stake represent in this filing?

The reporting group states its aggregate Masimo holding equals 6.2% of the common stock. That percentage is based on 74,218,782 shares outstanding as of February 13, 2026, the figure disclosed in the merger agreement included with Masimo’s Form 8-K.

What merger involving Masimo (MASI) is described in this Schedule 13D/A amendment?

The filing notes a Merger Agreement between Masimo and Danaher. A Danaher subsidiary, Mobius Merger Sub, will merge with Masimo, leaving Masimo as the surviving corporation and a wholly owned Danaher subsidiary, subject to the terms and conditions of that agreement.

How is Politan Capital committing its Masimo (MASI) shares regarding the Danaher merger?

Politan entered into a Voting and Support Agreement with Danaher, the merger subsidiary, and Masimo. Under this agreement, Politan agrees to vote its Masimo shares in favor of adopting the merger agreement and approving the merger and to comply with customary transfer restrictions.

Did Politan report any recent Masimo (MASI) share trades in this 13D/A amendment?

No. The amendment explicitly states that no transactions in Masimo common stock were effected by the reporting persons during the 60 days before the filing date. This means their reported ownership reflects a largely unchanged position over that recent period.

Are any of Politan’s Masimo (MASI) shares pledged or subject to financing arrangements?

Yes. The document explains that a portion of Politan’s Masimo shares is held in collateral accounts supporting a standard margin loan facility between Politan Master Fund and unaffiliated financial lenders. Other than this and the Voting Agreement, no additional material arrangements are described.