[Form 4] MASIMO CORP Insider Trading Activity

Rhea-AI Filing Summary

Masimo Corporation (MASI) reported an insider equity transaction by its CTIO and EVP of Engineering on November 13, 2025. A previously granted award of 2,474 restricted stock units (RSUs), originally granted on November 13, 2024, vested in full and was converted into the same number of shares of common stock. To cover tax withholding obligations tied to this vesting, 974 shares were withheld by the company at a stated price of $152.43 per share for the acquisition transaction and $0 for the tax withholding entry. Following these transactions, the officer directly held 3,268 shares of Masimo common stock, reflecting the updated beneficial ownership after the RSU vesting and tax withholding.

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

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^*

Ahmed Omar

(Last) (First) (Middle)

C/O MASIMO CORPORATION

52 DISCOVERY

(Street)

IRVINE CA 92618

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MASIMO CORP [ MASI ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CTIO & EVP of Engineering

3. Date of Earliest Transaction (Month/Day/Year)
11/13/2025

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	11/13/2025		M		2,474	A	$152.43	4,242	D
Common Stock	11/13/2025		F		974(1)	D	$0	3,268	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
Restricted Stock Units	(2)	11/13/2025		M			2,474	(3)	11/13/2034	Common Stock	2,474	$0	0	D

Explanation of Responses:

1. These shares were withheld by the Issuer in order to satisfy certain tax withholding obligations in connection with the issuance of shares upon the vesting of certain restricted stock units.

2. Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of the Issuer upon vesting of the RSU.

3. This RSU award was granted on November 13, 2024 and vested in full on November 13, 2025.

Remarks:

	/s/ Micah W. Young, Attorney-In-Fact	11/17/2025
	** 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 Masimo (MASI) disclose in this Form 4?

Masimo disclosed that its CTIO and EVP of Engineering had 2,474 restricted stock units vest on November 13, 2025, which were converted into the same number of shares of common stock.

How many Masimo (MASI) shares were withheld for taxes in this Form 4?

The filing states that 974 shares of Masimo common stock were withheld by the issuer to satisfy tax withholding obligations related to the RSU vesting.

What is the reporting person’s new Masimo (MASI) share ownership after the transaction?

After the reported transactions, the officer beneficially owned 3,268 shares of Masimo common stock in direct ownership.

What position does the reporting person hold at Masimo (MASI)?

The reporting person is an officer of Masimo, serving as CTIO & EVP of Engineering, as indicated in the relationship section.

What do the restricted stock units (RSUs) in this Masimo (MASI) filing represent?

Each restricted stock unit (RSU) represents a contingent right to receive one share of Masimo common stock upon vesting, according to the explanation of responses.

When were the Masimo (MASI) RSUs granted and when did they vest?

The RSU award of 2,474 units was granted on November 13, 2024 and vested in full on November 13, 2025, after which no RSUs from this award remained outstanding.