Masimo Ownership | Who Owns Masimo?

Overview Forecast RevenueFinancials Chart Transcripts

Masimo Ownership Summary

Masimo is owned by 99.63% institutional investors, 4.97% insiders. Blackrock is the largest institutional shareholder, holding 17.64% of MASI shares. MFS Mid Cap Growth Equity is the top mutual fund, with 3.12% of its assets in Masimo shares.

MASI Ownership Benchmark

Type	Name	% Inst	% Insiders	% Retail
Stock	Masimo	99.63%	4.97%	-4.60%
Sector	Healthcare Stocks	35.58%	11.87%	52.55%
Industry	Medical Device Stocks	35.88%	10.92%	53.20%

Institutional Shareholders

Top Institutional Shareholders by Total Shares

Holder	Shares	% Holding	Value
Blackrock	9.35M	17.64%	$1.18B
Blackrock funding, inc. /de	4.64M	8.67%	$826.13M
Politan capital management lp	4.59M	8.56%	$816.36M
Vanguard group	4.35M	8.05%	$565.60M
Pentwater capital management lp	3.18M	5.93%	$564.92M
Barclays	2.74M	5.12%	$488.07M
Hbk investments l p	2.58M	4.81%	$458.21M
Massachusetts financial services co /ma/	2.34M	4.37%	$416.69M
Fmr	1.45M	2.71%	$258.06M
State street	1.44M	2.68%	$255.73M

Top Institutional Shareholders by % of Total Assets

Holder	Shares	% Assets	Value
Ace management global	47.69K	100.00%	$7.88M
Politan capital management lp	4.59M	82.89%	$816.36M
Beryl capital management	217.10K	35.19%	$38.62M
Slotnik capital	240.30K	12.50%	$42.74M
Cibra capital	90.38K	7.76%	$16.08M
Nuance investments	244.70K	6.07%	$43.53M
Hbk investments l p	2.58M	4.65%	$458.21M
First trust capital management	479.40K	4.48%	$85.27M
Fort baker capital management lp	312.72K	4.37%	$55.62M
Ensemble capital management	407.10K	3.99%	$51.27M

Top Buyers

Holder	Shares	% Assets	Change
Pentwater capital management lp	3.18M	2.93%	3.18M
Barclays	2.74M	0.12%	2.69M
Hbk investments l p	2.58M	4.65%	2.58M
Blackrock	9.35M	0.03%	1.47M
Millennium management	988.85K	0.07%	800.89K

Top Sellers

Holder	Shares	% Assets	Change
Fmr	1.45M	0.01%	-6.41M
Blackrock funding, inc. /de	4.64M	0.01%	-4.21M
T. rowe price investment management	-	-	-2.33M
Naya capital management uk	-	-	-1.56M
Alyeska investment group	-	-	-1.26M

New Positions

Holder	Shares	% Assets	Change	Value
Pentwater capital management lp	3.18M	2.93%	3.18M	$564.92M
Hbk investments l p	2.58M	4.65%	2.58M	$458.21M
Balyasny asset management	770.99K	0.18%	770.99K	$137.14M
Fil	482.00K	0.07%	482.00K	$85.73M
First trust capital management	479.40K	4.48%	479.40K	$85.27M

Sold Out

Holder	Change
Clearstead trust	-1.00
Financial management professionals	-1.00
Financial synergies wealth advisors	-2.00
Claris advisors, llc / mo /	-2.00
Advisornet financial	-2.00

Institutional Ownership Trends

Date	Holdings	Change %	Shares	Change %	Ownership	Change %	Increased Position	Change %	Decreased Position	Change %
Mar 31, 2026	449	13.67%	53,400,785	-3.48%	99	0.95%	267	43.55%	104	-21.21%
Dec 31, 2025	126	-65.00%	8,662,748	-84.58%	16	0.15%	52	-68.29%	38	-68.85%
Sep 30, 2025	147	-61.21%	10,193,987	-82.28%	18	0.17%	58	-66.67%	54	-59.40%
Jun 30, 2025	375	-5.54%	56,778,550	4.69%	105	1.04%	171	-19.34%	132	11.86%
Mar 31, 2025	392	5.38%	54,108,094	5.12%	100	1.08%	209	20.11%	117	-4.10%

Top Mutual Funds Shareholders

Holder	Shares	% Holding	Change
MFS Mid Cap Growth Equity	1.64M	3.12%	-7.58K
MFS Mid Cap Growth A	1.64M	3.12%	-
iShares Core S&P Mid-Cap ETF	1.54M	2.94%	-784.00
Vanguard US Total Market Shares ETF	1.53M	2.83%	-71.94K
Vanguard Total Stock Mkt Idx Inv	1.46M	2.78%	3.35K
BlackRock Mid-Cap Growth Equity Instl	1.20M	2.20%	-18.64K
BlackRock Global Uncons Eq Z USD Acc	1.07M	2.04%	-9.11K
Vanguard Small Cap Index	1.05M	2.01%	-2.20K
Fidelity Select Health Care	1.00M	1.92%	-230.00K
BlackRock Event Driven Equity Instl	971.82K	1.86%	-

Recent Insider Transactions

Date	Name	Role	Activity	Value
Jan 28, 2026	Sampath Anand	EVP, Ops & Clinical Research	Sell	$27.07K
Jan 28, 2026	Sampath Anand	EVP, Ops & Clinical Research	Sell	$900.16K
Jan 28, 2026	Sampath Anand	EVP, Ops & Clinical Research	Sell	$1.63M
Aug 12, 2025	Brennan Michelle	Chairman of the Board	Buy	$15.04K
Aug 13, 2025	Brennan Michelle	Chairman of the Board	Buy	$15.53K

Insider Transactions Trends

Date	Buy	Sell
2026 Q1	-	3
2025 Q4	-	-
2025 Q3	3	-
2025 Q2	-	3
2025 Q1	-	9

MASI Ownership FAQ

Who Owns Masimo?

Masimo shareholders are primarily institutional investors at 99.63%, followed by 4.97% insiders and -4.60% retail investors. The average institutional ownership in Masimo's industry, Medical Device Stocks, is 35.88%, which Masimo exceeds.

Who owns the most shares of Masimo?

Masimo’s largest shareholders are Blackrock (9.35M shares, 17.64%), Blackrock funding, inc. /de (4.64M shares, 8.67%), and Politan capital management lp (4.59M shares, 8.56%). Together, they hold 34.87% of Masimo’s total shares outstanding.

Does Blackrock own Masimo?

Yes, BlackRock owns 17.64% of Masimo, totaling 9.35M shares as of Jun 2024. This represents 0.03% of BlackRock's total assets, with a market value of 1.18B$. In the last quarter, BlackRock increased its holdings by 1.47M shares, a 18.66% change.

Who is Masimo’s biggest shareholder by percentage of total assets invested?

Ace management global is Masimo’s biggest shareholder by percentage of total assets invested, with 100.00% of its assets in 47.69K Masimo shares, valued at 7.88M$.

Who is the top mutual fund holder of Masimo shares?

MFS Mid Cap Growth Equity is the top mutual fund holder of Masimo shares, with 3.12% of its total shares outstanding invested in 1.64M Masimo shares.

Try Tickergate Pro Free

Customize Everything. 100% Flexibility. Fast and Easy to Use (No code or Excel Needed)

Customize your own personal stocks lists, views and charts
Choose from hundreds of fields, up to 15 years of history
Conduct deep comparison analysis

Discover trending investment themes
Find your next best investment
Research stocks using tools