MasimoMASI
13F holders, Q1 2026 (March 31)451holders +59
125new positions
69sold out
11famous investors
$177.40avg. 13F price*
At the end of Q1 2026, 451 institutions reported holding Masimo Corp. (MASI) in their 13F filings, up 59 from Q4 2025. 125 opened new positions and 69 sold out. The largest holders were BlackRock, Inc. ($826.1M), Politan Capital Management LP ($816.4M) and Pentwater Capital Management LP ($564.9M). 11 famous investors held it, including George Soros (0.3% of Soros Fund Management's portfolio), Joel Greenblatt (0.2% of Gotham Asset Management's portfolio) and Mario Gabelli (0.2% of GAMCO Investors's portfolio).
- Company
- Masimo Corp.
- CUSIP
- 574795100
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q4 2025 → Q1 2026
| Institutions | Total Value | |
|---|---|---|
| New Positions | 125 | $2.6B |
| Exits | 69 | $1.0B |
All 13F filers, Q4 2025 → Q1 2026: 22,968,045 shares bought and 24,184,048 shares sold, net −1,216,003 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 451 holders
| BlackRock, Inc. | 0.01% | Reduce -47.5% | 4,644,578 | $826.1M |
| Politan Capital Management LP | 82.89% | No change | 4,589,648 | $816.4M |
| Pentwater Capital Management LP | 4.01% | New | 3,176,000 | $564.9M |
| Barclays PLC | 0.17% | Add +4602.0% | 2,743,985 | $488.1M |
| HBK Investments L P | 6.26% | New | 2,576,109 | $458.2M |
| Massachusetts Financial Services Co. | 0.14% | Reduce -12.1% | 2,342,790 | $416.7M |
| Vanguard Capital Management LLC | 0.01% | — | 2,050,045 | $364.6M |
| Vanguard Portfolio Management LLC | 0.02% | — | 2,006,861 | $357.0M |
| FMR LLC | 0.01% | Reduce -81.5% | 1,450,823 | $258.1M |
| State Street Corp. | 0.01% | Add +1.6% | 1,437,724 | $255.7M |
| Millennium Management | 0.14% | Add +426.1% | 988,853 | $175.9M |
| Goldman Sachs Group Inc. | 0.02% | Add +54.6% | 984,192 | $175.1M |
| Geode Capital Management, LLC | 0.01% | Add +0.3% | 956,736 | $170.2M |
| AQR Capital Management | 0.07% | Reduce -23.8% | 831,966 | $147.4M |
| Balyasny Asset Management L.P. | 0.28% | New | 770,986 | $137.1M |
| Morgan Stanley | 0.01% | Reduce -18.3% | 752,417 | $133.8M |
| Davidson Kempner Capital Management LP | 2.85% | New | 585,988 | $104.2M |
| JPMorgan Chase & Co. | 0.01% | Add +386.1% | 572,645 | $101.5M |
| Citigroup Inc. | 0.06% | Add +340.0% | 533,388 | $94.9M |
| SG Americas Securities, LLC | 0.10% | Add +3082.3% | 522,824 | $93.0M |
| FIL Ltd | 0.07% | New | 482,000 | $85.7M |
| First Trust Capital Management L.P. | 4.48% | New | 479,403 | $85.3M |
| HSBC Holdings PLC | 0.05% | New | 473,434 | $84.3M |
| UBS Group AG | 0.01% | Reduce -21.9% | 468,257 | $83.3M |
| Magnetar Financial LLC | 0.82% | Add +7729.2% | 427,081 | $76.0M |
| AQR Arbitrage LLC | 1.45% | New | 416,956 | $73.9M |
| O'Connor Alternative Investments LLC | 4.16% | — | 412,903 | $73.4M |
| Neuberger Berman Group LLC | 0.05% | Add +7956.5% | 403,309 | $71.7M |
| Northern Trust Corp. | 0.01% | Add +2.6% | 390,437 | $69.4M |
| Squarepoint Ops LLC | 0.15% | Reduce -33.3% | 389,359 | $69.3M |
| Charles Schwab Investment Management Inc. | 0.01% | Add +6.9% | 386,898 | $68.8M |
| Capital Research Global Investors | 0.01% | Reduce -43.7% | 359,058 | $63.9M |
| Gotham Asset Management | 0.19% | Reduce -0.2% | 341,468 | $60.7M |
| Westfield Capital Management Co. LP | 0.25% | Reduce -77.6% | 341,229 | $60.7M |
| Alliancebernstein L.P. | 0.02% | Add +739.8% | 455,354 | $59.2M |
| Hudson Bay Capital Management LP | 0.40% | New | 330,679 | $58.8M |
| Corient Private Wealth LP | 0.08% | Reduce -5.5% | 321,600 | $57.2M |
| Fort Baker Capital Management LP | 5.84% | New | 312,720 | $55.6M |
| Nexpoint Asset Management, L.P. | 3.86% | New | 310,130 | $55.2M |
| Capitolis Liquid Global Markets LLC | 0.35% | — | 309,102 | $55.0M |
| Bank of New York Mellon Corp | 0.01% | Reduce -0.7% | 306,400 | $54.5M |
| Qube Research & Technologies Ltd | 0.07% | Reduce -0.7% | 291,481 | $51.8M |
| Vanguard Fiduciary Trust Co. | 0.01% | — | 289,867 | $51.6M |
| Citadel Advisors | 0.04% | Add +553.5% | 281,366 | $50.0M |
| Whitebox Advisors LLC | 2.61% | New | 270,001 | $48.0M |
| HRT Financial LP | 0.12% | Add +185.5% | 264,837 | $47.1M |
| Nuance Investments, LLC | 6.07% | New | 244,704 | $43.5M |
| Amundi | 0.01% | Add +454.4% | 243,143 | $43.2M |
| Slotnik Capital, LLC | 12.70% | New | 240,300 | $42.7M |
| Renaissance Technologies | 0.07% | Add +299.8% | 239,500 | $42.6M |
| Polar Asset Management Partners Inc. | 1.34% | New | 232,026 | $41.3M |
| Bank of America Corp. | 0.00% | Reduce -18.5% | 232,003 | $41.3M |
| MUFG Securities EMEA plc | 0.60% | New | 225,400 | $40.1M |
| Beryl Capital Management LLC | 35.54% | New | 217,103 | $38.6M |
| Canada Pension Plan Investment Board | 0.02% | Add +444.2% | 209,500 | $37.3M |
| Erste Asset Management GmbH | 0.33% | No change | 200,000 | $35.5M |
| Water Island Capital LLC | 4.86% | New | 194,197 | $34.5M |
| Alpine Associates Management Inc. | 1.98% | New | 189,000 | $33.6M |
| American Century Companies Inc. | 0.02% | Add +5.2% | 188,073 | $33.5M |
| Arrowstreet Capital, Limited Partnership | 0.02% | New | 172,588 | $30.7M |
| Readystate Asset Management LP | 3.13% | New | 171,115 | $30.4M |
| Raymond James Financial Inc. | 0.01% | Reduce -8.6% | 170,527 | $30.3M |
| Man Group plc | 0.06% | Add +12.8% | 166,235 | $29.6M |
| Dimensional Fund Advisors LP | 0.01% | Reduce -5.5% | 164,402 | $29.2M |
| Glazer Capital, LLC | 0.62% | New | 157,858 | $28.1M |
| Woodline Partners LP | 0.10% | New | 153,234 | $27.3M |
| Bank of Nova Scotia | 0.05% | Add +2808.0% | 152,584 | $27.1M |
| Tudor Investment Corporation | 0.14% | Add +785.9% | 143,884 | $25.6M |
| Capula Management Ltd | 0.22% | New | 142,800 | $25.4M |
| Champlain Investment Partners, LLC | 0.32% | New | 141,284 | $25.1M |
| Westchester Capital Management, LLC | 1.19% | New | 138,428 | $24.6M |
| GMO | 0.06% | Reduce -4.3% | 137,617 | $24.5M |
| TIG Advisors, LLC | 1.15% | New | 135,197 | $24.0M |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 0.00% | Add +12.4% | 133,689 | $23.8M |
| Rhumbline Advisers | 0.02% | Add +4.1% | 129,619 | $23.1M |
| Gabelli Funds LLC | 0.15% | Add +285.6% | 126,082 | $22.4M |
| GW&K Investment Management, LLC | 0.19% | Add +2.9% | 122,781 | $21.8M |
| Sagefield Capital LP | 1.56% | New | 122,240 | $21.7M |
| Schonfeld Strategic Advisors LLC | 0.17% | Reduce -55.7% | 117,297 | $20.9M |
| WINTON GROUP Ltd | 0.70% | New | 112,783 | $20.1M |
| Weiss Asset Management LP | 0.52% | New | 112,600 | $20.0M |
| Nuveen, LLC | 0.01% | Reduce -50.2% | 111,542 | $19.8M |
| Nomura Holdings Inc. | 0.16% | New | 109,390 | $19.5M |
| Blackstone Inc. | 0.08% | New | 109,383 | $19.5M |
| Principal Financial Group Inc. | 0.01% | Add +5.0% | 102,718 | $18.3M |
| Soros Fund Management | 0.33% | New | 100,838 | $17.9M |
| Kryger Capital LLC | 1.27% | — | 100,589 | $17.9M |
| Schroder Investment Management Group | 0.01% | Reduce -79.8% | 96,179 | $17.1M |
| GAMCO Investors | 0.16% | Add +10.8% | 92,000 | $16.4M |
| Marshall Wace, LLP | 0.02% | Reduce -58.7% | 90,657 | $16.1M |
| CIBRA Capital Ltd | 7.76% | New | 90,376 | $16.1M |
| Swiss National Bank | 0.01% | Reduce -0.9% | 90,300 | $16.1M |
| Deutsche Bank AG | 0.01% | Add +1227.0% | 89,387 | $15.9M |
| GABELLI & Co INVESTMENT ADVISERS, INC. | 2.35% | New | 88,650 | $15.8M |
| California Public Employees Retirement System | 0.01% | Add +22.2% | 77,397 | $13.8M |
| Voloridge Investment Management, LLC | 0.05% | Add +77.0% | 70,000 | $12.5M |
| Invesco Ltd. | 0.00% | Reduce -78.3% | 69,144 | $12.3M |
| Healthcare of Ontario Pension Plan Trust Fund | 0.02% | New | 67,600 | $12.0M |
| Verition Fund Management LLC | 0.12% | Add +26.1% | 66,853 | $11.9M |
| Ameriprise Financial Inc. | 0.00% | Reduce -86.1% | 65,203 | $11.6M |
"% of holder's portfolio" is MASI's weight in each manager's 13F, not the share of Masimo Corp. the manager owns.