[Form 4] MASIMO CORP Insider Trading Activity

Rhea-AI Filing Summary

Tripodi Blair, Chief Operating Officer, Consumer Division of Masimo Corporation (MASI), reported transactions on Form 4 dated 09/23/2025. On that date 15,000 restricted stock units (granted March 1, 2024) were treated as acquired/settled using a $142.13 per-share price, and 8,078 shares were withheld to satisfy tax withholding. After these transactions the filing shows beneficial ownership figures of 21,896 and 13,818 shares for the reported classes. The filing states the RSUs fully accelerated on 09/23/2025 because Mr. Tripodi resigned for "good reason" in connection with the Company’s sale of its consumer audio business.

Positive

• 15,000 restricted stock units vested and were settled, providing clear disclosure of executive compensation treatment
• Company disclosed that the RSU acceleration was triggered by a defined contractual "good reason" separation in connection with the sale of the consumer audio business

Negative

• Resignation of COO, Consumer Division (Tripodi Blair) occurred on 09/23/2025 as noted in the filing
• 8,078 shares were withheld to satisfy tax withholding, reducing the net shares delivered to the reporting person

Insights

Corporate Governance Expert

TL;DR: Officer resignation triggered full acceleration of unvested RSUs tied to a divestiture; this is a material insider change for governance disclosure.

The Form 4 documents a compensation-related acceleration and an officer departure linked to the sale of Masimo's consumer audio business. The grant date for the RSUs was March 1, 2024, and 15,000 units vested/settled on 09/23/2025 with 8,078 shares withheld for taxes. Such accelerations are standard when separation-for-good-reason provisions apply, but they alter executive ownership and should be noted by governance stakeholders monitoring executive retention terms and post-transaction transitions.

Securities Analyst

TL;DR: Insider received 15,000 shares on vesting and had 8,078 shares withheld for taxes; the event follows a divestiture and officer resignation.

The filing shows an effective settlement of RSUs using the prior-day stock price of $142.13. After the transactions reported for 09/23/2025, the insider’s beneficial ownership is shown as 21,896 shares (and 13,818 on the other line), reflecting the net effect of settlement and tax withholding. This is a disclosure of insider compensation settlement and change in executive status rather than an operational or earnings disclosure.

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

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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Tripodi Blair

(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)
	COO, Consumer Division

3. Date of Earliest Transaction (Month/Day/Year)
09/23/2025

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	09/23/2025		M		15,000	A	$142.13(1)	21,896	D
Common Stock	09/23/2025		F		8,078(2)	D	$0	13,818	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	(3)	09/23/2025		M			15,000	(4)	(4)	Common Stock	15,000(5)	$0	0	D

Explanation of Responses:

1. The transaction was completed prior to the market open on September 23, 2025, and the Company used the stock price from prior day for the restricted stock unit settlement and related payroll tax purposes.

2. 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.

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

4. These restricted stock units were granted on March 1, 2024.

5. On September 23, 2025, in connection with the Company's sale of its consumer audio business, Mr. Tripodi resigned from the Company for good reason, as defined in the Restricted Stock Unit Award Agreement applicable to this grant, resulting in the full acceleration of the remaining unvested restricted stock units.

Remarks:

	/s/ Micah W. Young, Attorney-In-Fact	09/25/2025
	** 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 transactions did MASI insider Tripodi Blair report on Form 4 dated 09/23/2025?

The report shows 15,000 RSUs treated as acquired/settled on 09/23/2025 and 8,078 shares withheld for tax withholding in connection with that settlement.

Why did the restricted stock units accelerate for Tripodi Blair?

The filing states the RSUs fully accelerated because Mr. Tripodi resigned for "good reason" in connection with the Company's sale of its consumer audio business.

What share counts are shown after the reported transactions?

The Form 4 lists beneficial ownership figures of 21,896 and 13,818 shares following the reported transactions.

What price was used to value the settled RSUs?

The Company used the prior-day stock price of $142.13 for the restricted stock unit settlement and related payroll tax purposes.

When were the restricted stock units originally granted?

The filing indicates those restricted stock units were granted on March 1, 2024.