[Form 4] Masimo Corporation Insider Trading Activity

Rhea-AI Filing Summary

Charles Dadswell, a director of Masimo Corporation (MASI), reported equity awards granted on August 18, 2025. The filing shows 2,273 restricted stock units (RSUs), each representing a contingent right to one share, and a non-qualified stock option covering 5,104 shares with an exercise price of $153.93. The RSUs vest ratably over four years with 25% vesting on each anniversary of the grant date. The option vests over five years with 20% vesting on each anniversary and is exercisable as it vests.

The Form 4 was filed individually and signed by an attorney-in-fact on behalf of the reporting person. All information in this summary is taken directly from the Form 4 content.

Positive

• Equity grants disclosed: 2,273 RSUs and an option for 5,104 shares, providing clear compensation detail
• Long-term vesting schedules: RSUs vest over four years and the option vests over five years, aligning incentives

Negative

• Option exercise price disclosed: $153.93, which could delay intrinsic value until stock price exceeds that level
• Vesting delays liquidity: Both awards vest over multi-year schedules, meaning no immediate share receipt

Insights

Financial Analyst

TL;DR Director received standard multi-year equity awards: RSUs and time‑vesting options, reflecting typical compensation not indicating immediate market-moving changes.

The disclosed grants total 2,273 RSUs and a non‑qualified option for 5,104 shares at an exercise price of $153.93. Vesting schedules (four years for RSUs, five years for the option) spread potential dilution and align incentives long‑term. This is a routine insider compensation disclosure and does not by itself provide revenue, earnings, or material corporate-event information.

Corporate Governance Expert

TL;DR Reported grants follow customary multi-year vesting patterns for directors and signal retention/incentive alignment rather than a governance red flag.

The Form 4 explicitly states the RSUs vest 25% annually over four years and the option vests 20% annually over five years, with exercisability tied to vesting. The filing is individual, properly executed by an attorney‑in‑fact, and contains clear explanatory remarks. From a governance perspective, the structure is conventional and provides long‑term alignment between the director and shareholders.

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

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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^*

Dadswell Charles

(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)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/18/2025

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

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	(1)							(2)	08/18/2035	Common Stock	2,273		0	D
Non-Qualified Stock Option (Right to Buy)	$153.93							(3)	08/18/2035	Common Stock	5,104		0	D

Explanation of Responses:

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

2. This RSU award was granted on August 18, 2025 and will vest ratably over four years, with 25% of the award vesting on each anniversary of the grant date.

3. This option was granted on August 18, 2025 and is exercisable as the option vests. The option vests over a five year period, with 20% of the shares subject to the option vesting on each anniversary of the grant date.

Remarks:

	/s/ Micah W. Young, Attorney-In-Fact	09/03/2025
	** 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.
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FAQ

What did MASI director Charles Dadswell receive according to the Form 4?

The Form 4 shows 2,273 restricted stock units (RSUs) and a non‑qualified stock option for 5,104 shares with an exercise price of $153.93 granted on August 18, 2025.

How do the RSUs and options vest for MASI director grants?

The RSUs vest ratably over four years with 25% vesting on each anniversary. The option vests over five years with 20% annual vesting and is exercisable as it vests.

Was the Form 4 filed individually or jointly for MASI (MASI)?

The filing indicates it was a Form filed by one reporting person (individual filing).

What is the exercise price of the option disclosed for MASI insider?

The non‑qualified stock option has an exercise price of $153.93 as stated in the filing.

Who signed the Form 4 for the reporting person?

The Form 4 is signed by Micah W. Young, Attorney‑In‑Fact on behalf of the reporting person, dated 09/03/2025.