Charles Dadswell - 10 Jun 2026 Form 4 Insider Report for MASIMO CORP (MASI)

Reporting relationship: EVP, General Counsel
Issuer ticker: MASI
Reported as of: 10 Jun 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 12 Jun 2026, 16:31:51 UTC
Prior SEC filing: 10 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ Micah W. Young, Attorney-In-Fact

Key filing fact

Charles Dadswell filed Form 4 for MASIMO CORP (MASI) on 12 Jun 2026.

Key facts

This page summarizes Charles Dadswell's Form 4 filing for MASIMO CORP (MASI).
2 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 12 Jun 2026, 16:31.

Change

Previous filing in this sequence was filed on 10 Mar 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001575229 Primary reporting owner

Dadswell Charles

Relationship: EVP, General Counsel
Address: C/O MASIMO CORPORATION, 52 DISCOVERY, IRVINE
Signature: /s/ Micah W. Young, Attorney-In-Fact
Signature date: 12 Jun 2026

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

MASI transaction Derivative

Restricted Stock Units

Disposed to Issuer

Transaction value
Shares: -11,886
Change %: -100%
Price
Shares after: 0
Date: 10 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 11,886
Exercise price
Footnotes: F1, F2, F3

MASI transaction Derivative

Restricted Stock Units

Disposed to Issuer

Transaction value
Shares: -10,261
Change %: -100%
Price
Shares after: 0
Date: 10 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 10,261
Exercise price
Footnotes: F1, F2, F4

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Section 16 status

Charles Dadswell is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may still apply in specific circumstances.

Explanation of responses 4 footnotes

Footnote F1

On June 10, 2026, pursuant to the Agreement and Plan of Merger, dated February 16, 2026, by and among Masimo Corporation (the "Issuer"), Danaher Corporation ("Parent"), and Mobius Merger Sub, Inc. ("Merger Sub"), Merger Sub merged with and into the Issuer, with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent (the "Merger").

Footnote F2

On June 10, 2026, at the effective time of the Merger, each of the Issuer's restricted stock units ("RSUs") (other than certain RSUs held by the Issuer's non-employee directors) was assumed by Parent and converted into a number of RSUs of Parent equal to the product of the number of shares of Parent common stock equal to the number of shares of the Issuer's common stock, par value $0.001 per share underlying such RSU multiplied by the quotient of (a) $180.00 per share, without interest, divided by (b) the volume-weighted average trading price per share of Parent's common stock for the ten trading day period ending on and including June 10, 2026 ($183.33).

Footnote F3

Represents the unvested portion of RSUs granted on October 22, 2025, which award of RSUs was to vest ratably over four years.

Footnote F4

Represents the unvested portion of RSUs granted on March 6, 2026, which award of RSUs was to vest ratably over four years.