Insider Transactions Reported by 28 Insiders of MASIMO CORP

Symbol: MASI on Nasdaq
Location: Irvine, CA

Quick Takeaways

MASI - MASIMO CORP has 28 insiders with reported activity on this page.
Net insider value flow over the last year: -$2,087,070.
Recent transaction rows are available for direct filing-level review.

What Changed

Buy value: $468,500; sell value: $2,555,570.
Net share flow: -15,480.

Why This Matters

This page gives a plain-language issuer insider context before you inspect transaction-level evidence.
Use the filing links below to verify timestamps, codes, and ownership impacts directly from SEC forms.

Source Evidence

Filed on Form 4

Issuer insider activity is sourced from SEC Forms 3, 4, and 5.

See Original Filing

Insider trading overview

Last 12 months

Net insider flow leans to selling over the last 12 months. Net value: -$2,087,070.

Buys

$468,500

Shares: 3,200

Insiders: 2

Sells

$2,555,570

Shares: 18,680

Insiders: 1

Net

-$2,087,070

Shares: -15,480

Insiders: 1

Window (months)	Buy shares	Sell shares	Buy $	Sell $	Net $
0-3	0	0	$0	$0	$0
3-6	0	18,680	$0	$2,555,570	-$2,555,570
6-9	0	0	$0	$0	$0
9-12	3,200	0	$468,500	$0	+$468,500

MASIMO CORP executives and other stock owners filed with the SEC include:

Name	Relationship	Holdings Value	Past Year Net Change	Change %	Valuation	Report Date
Politan Capital Management LP	Director by deputization	$744,390,354			Mixed	11 Mar 2026
Joe E. Kiani	CEO and Chairman of the Board, Director	$76,686,577			Mixed	08 Aug 2024
Thomas Samuel McClenahan	Evp, Gen Counsel & Corp Sec	$9,474,979			Mixed	28 Feb 2024
Anand Sampath	EVP, Operations	$5,649,123	-$2,555,570	-31%	Filing P/S	06 Mar 2026
Blair Tripodi	COO, Consumer Division	$4,885,319			Mixed	23 Sep 2025
Bilal Muhsin	Chief Operating Officer	$4,570,915			Mixed	12 May 2025
Tao Levy	EVP, Bus Dev	$4,334,641			Mixed	13 Nov 2024
Micah W. Young	EVP & Chief Financial Officer	$4,064,887			Mixed	11 Mar 2026
Craig B. Reynolds	Director	$3,064,557			Mixed	29 Apr 2025
Kevin P. Duffy	President, Consumer	$2,988,646			Mixed	11 Apr 2022
Catherine M. Szyman	CEO, Director	$2,470,965			Mixed	11 Mar 2026
Michelle Brennan	Director, Chairman of the Board	$1,519,543	+$30,560	+2.1%	Median	23 Apr 2026
Thomas Harkin	Director	$1,042,301			Mixed	27 May 2021
Robert A. Chapek	Director	$857,996			Mixed	29 Apr 2025
William R. Jellison	Director	$740,486	+$437,940	+145%	Mixed	11 Aug 2025
Julie Ann Shimer	Director	$697,609			Mixed	26 May 2023
H. Michael Cohen	Director	$604,753			Mixed	26 May 2023
Timothy J. Scannell	Director	$495,748			Mixed	23 Apr 2026
Wendy E. Lane	Director	$495,748			Mixed	23 Apr 2026
Omar Ahmed	CTIO & EVP of Engineering	$467,029			Mixed	13 Nov 2025
Darlene J. S. Solomon	Director	$335,822			Mixed	29 Apr 2025
Rolf A. Classon	Director	$273,032			Mixed	19 Dec 2023
Adam Mikkelson	Director	$194,255			Mixed	26 Jun 2023
Elisabeth A. Hellmann	Chief Human Resources Officer	$38,064			Median	21 Apr 2026
Tim Benner	Chief Marketing Officer				Mixed	06 Mar 2026
Paul Hataishi	SVP, Chief Accounting Officer				Mixed	27 Feb 2023
Greg Allen Meehan	Chief Commerical Officer				Mixed	06 Mar 2026
Charles Dadswell	EVP, General Counsel				Mixed	06 Mar 2026

Top shareholders of MASIMO CORP (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.

Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

Holder	Source	Role / Reporting	Ownership %	Shares	Holdings Value	12M Net Δ	As of	Details
BlackRock, Inc.	13F 13D/G	Company	7.9% from 13D/G	4,644,578	$826,131,120	—	31 Mar 2026	13F 13D/G
Politan Capital Management LP	13F 13D/G 3/4/5	Company · Quentin Koffey · Director by deputization	6.2% from 13D/G	4,589,648	$816,360,690	—	31 Mar 2026	13F 13D/G 3/4/5
Joe E. Kiani	13D/G 3/4/5	Joe Kiani · CEO and Chairman of the Board, Director	6.5%	3,657,039	$652,671,750	-$401,127,387	31 Mar 2026	13D/G 3/4/5
Pentwater Capital Management LP	13D/G 13F	Company	6.1%	3,176,000	$566,820,720	$0	31 Mar 2026	13D/G 13F
BARCLAYS PLC	13D/G 13F	Company	5.5%	2,892,262	$516,181,999	$0	31 Mar 2026	13D/G 13F
HBK INVESTMENTS L P	13F	Company	4.9%	2,576,109	$458,212,508	—	31 Mar 2026	13F
MASSACHUSETTS FINANCIAL SERVICES CO /MA/	13F	Company	4.5%	2,342,790	$416,692,672	—	31 Mar 2026	13F
VANGUARD CAPITAL MANAGEMENT LLC	13F	Company	3.9%	2,050,045	$364,641,504	—	31 Mar 2026	13F
VANGUARD PORTFOLIO MANAGEMENT LLC	13F	Company	3.9%	2,006,861	$356,960,366	—	31 Mar 2026	13F
FMR LLC	13D/G 13F	Company	4.5%	2,349,975	$317,340,559	-$767,176,959	27 Feb 2026	13D/G 13F
STATE STREET CORP	13F	Company	2.8%	1,437,724	$255,727,968	—	31 Mar 2026	13F
MILLENNIUM MANAGEMENT LLC	13F	Company	1.9%	988,853	$175,887,283	—	31 Mar 2026	13F
GOLDMAN SACHS GROUP INC	13F	Company	1.9%	984,192	$175,058,231	—	31 Mar 2026	13F
GEODE CAPITAL MANAGEMENT, LLC	13F	Company	1.8%	956,736	$170,210,661	—	31 Mar 2026	13F
AQR CAPITAL MANAGEMENT LLC	13F	Company	1.6%	831,966	$147,399,452	—	31 Mar 2026	13F
BALYASNY ASSET MANAGEMENT L.P.	13F	Company	1.5%	770,986	$137,135,280	—	31 Mar 2026	13F
MORGAN STANLEY	13F	Company	1.4%	752,417	$133,832,703	—	31 Mar 2026	13F
JPMORGAN CHASE & CO	13F	Company	1.1%	572,645	$101,541,410	—	31 Mar 2026	13F
CITIGROUP INC	13F	Company	1%	533,388	$94,873,724	—	31 Mar 2026	13F
SG Americas Securities, LLC	13F	Company	1%	522,824	$92,995,000	—	31 Mar 2026	13F
FIL Ltd	13F	Company	0.93%	482,000	$85,733,340	—	31 Mar 2026	13F
First Trust Capital Management L.P.	13F	Company	0.92%	479,403	$85,271,412	—	31 Mar 2026	13F
HSBC HOLDINGS PLC	13F	Company	0.91%	473,434	$84,266,518	—	31 Mar 2026	13F
UBS Group AG	13F	Company	0.9%	468,257	$83,288,873	—	31 Mar 2026	13F
Liontrust Investment Partners LLP	13F	Company	1.2%	627,796	$81,651,148	—	31 Mar 2026	13F
Magnetar Financial LLC	13F	Company	0.82%	427,081	$75,964,897	—	31 Mar 2026	13F
AQR Arbitrage LLC	13F	Company	0.8%	416,956	$73,872,095	—	31 Mar 2026	13F
Neuberger Berman Group LLC	13F	Company	0.77%	403,309	$71,736,572	—	31 Mar 2026	13F
NORTHERN TRUST CORP	13F	Company	0.75%	390,437	$69,447,030	—	31 Mar 2026	13F
Squarepoint Ops LLC	13F	Company	0.75%	389,359	$69,255,285	—	31 Mar 2026	13F
CHARLES SCHWAB INVESTMENT MANAGEMENT INC	13F	Company	0.74%	386,898	$68,817,547	—	31 Mar 2026	13F
Capital Research Global Investors	13F	Company	0.69%	359,058	$63,865,646	—	31 Mar 2026	13F
Gotham Asset Management, LLC	13F	Company	0.66%	341,468	$60,736,913	—	31 Mar 2026	13F
WESTFIELD CAPITAL MANAGEMENT CO LP	13F	Company	0.66%	341,229	$60,694,349	—	31 Mar 2026	13F
ALLIANCEBERNSTEIN L.P.	13F	Company	0.87%	455,354	$59,223,341	—	31 Mar 2026	13F
Hudson Bay Capital Management LP	13F	Company	0.64%	330,679	$58,817,874	—	31 Mar 2026	13F
Corient Private Wealth LLC	13F	Company	0.62%	321,600	$57,202,996	—	31 Mar 2026	13F
Fort Baker Capital Management LP	13F	Company	0.6%	312,720	$55,623,507	—	31 Mar 2026	13F
NEXPOINT ASSET MANAGEMENT, L.P.	13F	Company	0.6%	310,130	$55,162,823	—	31 Mar 2026	13F
CAPITOLIS LIQUID GLOBAL MARKETS LLC	13F	Company	0.59%	309,102	$54,979,973	—	31 Mar 2026	13F
Bank of New York Mellon Corp	13F	Company	0.59%	306,400	$54,499,447	—	31 Mar 2026	13F
Qube Research & Technologies Ltd	13F	Company	0.56%	291,481	$51,845,725	—	31 Mar 2026	13F
VANGUARD FIDUCIARY TRUST CO	13F	Company	0.56%	289,867	$51,558,643	—	31 Mar 2026	13F
CITADEL ADVISORS LLC	13F	Company	0.54%	281,366	$50,046,570	—	31 Mar 2026	13F
WHITEBOX ADVISORS LLC	13F	Company	0.52%	270,001	$48,025,078	—	31 Mar 2026	13F
HRT FINANCIAL LP	13F	Company	0.51%	264,837	$47,106,000	—	31 Mar 2026	13F
NUANCE INVESTMENTS, LLC	13F	Company	0.47%	244,704	$43,525,500	—	31 Mar 2026	13F
Slotnik Capital, LLC	13F	Company	0.46%	240,300	$42,742,161	—	31 Mar 2026	13F
RENAISSANCE TECHNOLOGIES LLC	13F	Company	0.46%	239,500	$42,599,865	—	31 Mar 2026	13F
Polar Asset Management Partners Inc.	13F	Company	0.45%	232,026	$41,270,465	—	31 Mar 2026	13F

Recent Insider Transactions by Companies or Individuals for MASIMO CORP

Showing up to 300 most recent insider transactions from the last 12 months.

Insider	Symbol	Class	Transaction	%	Value $	* Price $	Shares	Shares Owned	Date	Ownership
Timothy J. Scannell	MASI	Common Stock	Options Exercise	88.6%			1,225	2,608	29 Apr 2026	Direct
Timothy J. Scannell	MASI	Restricted Stock Units	Options Exercise	-100%			-1,225	0	29 Apr 2026	Direct
Wendy E. Lane	MASI	Common Stock	Options Exercise	88.6%			1,225	2,608	29 Apr 2026	Direct
Wendy E. Lane	MASI	Restricted Stock Units	Options Exercise	-100%			-1,225	0	29 Apr 2026	Direct
Michelle Brennan	MASI	Common Stock	Options Exercise	16.7%			1,225	8,543	29 Apr 2026	Direct
Michelle Brennan	MASI	Restricted Stock Units	Options Exercise	-100%			-1,225	0	29 Apr 2026	Direct
Timothy J. Scannell	MASI	Restricted Stock Units	Award	100%			1,119	2,238	23 Apr 2026	Direct
Wendy E. Lane	MASI	Restricted Stock Units	Award	100%			1,119	2,238	23 Apr 2026	Direct
Michelle Brennan	MASI	Restricted Stock Units	Award	100%			1,119	2,238	23 Apr 2026	Direct
Elisabeth A. Hellmann	MASI	Common Stock	Tax liability	-36.1%			-121	214	21 Apr 2026	Direct
Elisabeth A. Hellmann	MASI	Common Stock	Options Exercise				335	335	21 Apr 2026	Direct
Elisabeth A. Hellmann	MASI	Restricted Stock Units	Options Exercise	-25%			-335	1,005	21 Apr 2026	Direct
Politan Capital Management LP	MASI	Forward Sale Contract (obligation to sell)	Other				130,869	130,869	12 Mar 2026	See footnotes
Catherine M. Szyman	MASI	Common Stock	Tax liability	-12.3%			-1,069	7,605	11 Mar 2026	Direct
Catherine M. Szyman	MASI	Common Stock	Options Exercise	32%			2,101	8,674	11 Mar 2026	Direct
Catherine M. Szyman	MASI	Restricted Stock Units	Options Exercise	-25%			-2,101	6,306	11 Mar 2026	Direct
Micah W. Young	MASI	Common Stock	Tax liability	-1.8%			-471	25,656	11 Mar 2026	Direct
Micah W. Young	MASI	Common Stock	Options Exercise	3.46%			873	26,127	11 Mar 2026	Direct
Micah W. Young	MASI	Restricted Stock Units	Options Exercise	-25%			-873	2,622	11 Mar 2026	Direct
Politan Capital Management LP	MASI	Forward Sale Contract (obligation to sell)	Other				142,681	142,681	11 Mar 2026	See footnotes
Greg Allen Meehan	MASI	Restricted Stock Units	Award				8,550	8,550	06 Mar 2026	Direct
Tim Benner	MASI	Restricted Stock Units	Award				6,128	6,128	06 Mar 2026	Direct
Elisabeth A. Hellmann	MASI	Restricted Stock Units	Award				5,985	5,985	06 Mar 2026	Direct
Anand Sampath	MASI	Restricted Stock Units	Award				6,840	6,840	06 Mar 2026	Direct
Charles Dadswell	MASI	Restricted Stock Units	Award				10,261	10,261	06 Mar 2026	Direct
Micah W. Young	MASI	Restricted Stock Units	Award				17,671	17,671	06 Mar 2026	Direct
Catherine M. Szyman	MASI	Restricted Stock Units	Award				39,904	39,904	06 Mar 2026	Direct
Micah W. Young	MASI	Common Stock	Tax liability	-24.3%			-8,093	25,254	27 Feb 2026	Direct
Micah W. Young	MASI	Common Stock	Award	81.8%			15,000	33,347	27 Feb 2026	Direct
Micah W. Young	MASI	Restricted Stock Units	Options Exercise	-100%			-15,000	0	27 Feb 2026	Direct
Micah W. Young	MASI	Common Stock	Tax liability	-5.77%			-1,123	18,347	26 Feb 2026	Direct
Micah W. Young	MASI	Common Stock	Award	11.7%			2,034	19,470	26 Feb 2026	Direct
Catherine M. Szyman	MASI	Common Stock	Tax liability	-41%			-4,568	6,573	12 Feb 2026	Direct
Catherine M. Szyman	MASI	Common Stock	Options Exercise				11,141	11,141	12 Feb 2026	Direct
Catherine M. Szyman	MASI	Restricted Stock Units	Options Exercise	-33.3%			-11,141	22,283	12 Feb 2026	Direct
Anand Sampath	MASI	Common Stock	Sale	-31.4%	$2,555,570	$136.81	-18,680	40,909	28 Jan 2026	Direct
Anand Sampath	MASI	Common Stock	Options Exercise	101.4%			30,000	59,589	28 Jan 2026	Direct
Anand Sampath	MASI	Non-Qualified Stock Option (Right to Buy)	Options Exercise	-100%			-30,000	0	28 Jan 2026	Direct
Omar Ahmed	MASI	Common Stock	Tax liability	-23%			-974	3,268	13 Nov 2025	Direct
Omar Ahmed	MASI	Common Stock	Options Exercise	139.9%			2,474	4,242	13 Nov 2025	Direct
Omar Ahmed	MASI	Restricted Stock Units	Options Exercise	-100%			-2,474	0	13 Nov 2025	Direct
Blair Tripodi	MASI	Common Stock	Tax liability	-36.9%			-8,078	13,818	23 Sep 2025	Direct
Blair Tripodi	MASI	Common Stock	Options Exercise	217.5%			15,000	21,896	23 Sep 2025	Direct
Blair Tripodi	MASI	Restricted Stock Units	Options Exercise	-100%			-15,000	0	23 Sep 2025	Direct
Politan Capital Management LP	MASI	Common Stock, par value $0.001 per share	Other	-2.69%			-126,888	4,589,648	29 Aug 2025	See footnotes
Michelle Brennan	MASI	Common Stock	Purchase	1.39%	$15,525	$155.25	100	7,318	13 Aug 2025	Direct
Michelle Brennan	MASI	Common Stock	Purchase	1.4%	$15,035	$150.35	100	7,218	12 Aug 2025	Direct
William R. Jellison	MASI	Common Stock	Purchase	167.6%	$437,940	$145.98	3,000	4,790	11 Aug 2025	Direct

* An asterisk sign (*) next to the price indicates that the price is likely invalid.