MASIMO CORP (MASI) Institutional Ownership Changes & 13F Activity

MASIMO CORP (MASI). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings. This page analyzes institutional buying and selling activity, new holdings, and sold-out positions among tracked filers. Notable filers include Renaissance Technologies LLC, Viking Global Investors, First Eagle U.S. Value, Durable Capital Partners, and Fundsmith.

Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q2 2020Polen Capital ManagementBuy5,15615,690$3,577
Q2 2020Renaissance Technologies LLCSell-4,10014,900$3,397
Q1 2020FundsmithSell-99,110475,853$84,283
Q1 2020Renaissance Technologies LLCSell-7,02119,000$3,365
Q1 2020Polen Capital ManagementBuy2,89110,534$1,866
Q4 2019Renaissance Technologies LLCSell-78,67926,021$4,113
Q4 2019Polen Capital ManagementBuy1,0357,643$1,208
Q3 2019Renaissance Technologies LLCSell-169,300104,700$15,578
Q3 2019Polen Capital ManagementBuy1026,608$983
Q2 2019FundsmithBuy84,300574,963$85,566
Q2 2019Renaissance Technologies LLCSell-71,000274,000$40,777
Q2 2019Polen Capital ManagementBuy4326,506$968
Q1 2019Renaissance Technologies LLCSell-193,300345,000$47,707
Q1 2019FundsmithBuy11,291490,663$67,849
Q1 2019Polen Capital ManagementBuy3516,074$840
Q4 2018FundsmithBuy479,372479,372$51,470
Q4 2018Renaissance Technologies LLCBuy235,500538,300$57,797
Q4 2018Polen Capital ManagementBuy1,8495,723$614
Q3 2018Renaissance Technologies LLCSell-208,700302,800$37,711
Q3 2018Polen Capital ManagementBuy3223,874$482
Q2 2018Polen Capital ManagementBuy3843,552$347
Q1 2018Renaissance Technologies LLCSell-40,600511,500$44,986
Q1 2018Polen Capital ManagementBuy3,1683,168$279
Q4 2017Renaissance Technologies LLCSell-131,300552,100$46,818
Q3 2017Renaissance Technologies LLCBuy62,900683,400$59,155
Q2 2017Renaissance Technologies LLCBuy191,400620,500$56,577
Q1 2017Renaissance Technologies LLCBuy255,700429,100$40,018
Q4 2016Renaissance Technologies LLCBuy94,900173,400$11,687
Q3 2016Renaissance Technologies LLCSell-65,30078,500$4,670
Q2 2016Renaissance Technologies LLCSell-88,900143,800$7,552

Frequently asked questions about MASI activity

  • Which institutional owners are buying MASI?

    Institutional owners buying MASI include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in MASI activity?

    "Buy" means an investor increased their reported position in MASI compared to the prior reporting period. This reflects growing exposure to MASIMO CORP (MASI) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in MASI increasing?

    Institutional interest in MASI can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.

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