Masimo Corp
MASIDelisted- Industry
- Electromedical & Electrotherapeutic Apparatus
- SEC CIK
- 0000937556
Masimo Corp was delisted in 2026; its insiders filed their last Form 4 on Jun 12, 2026; 451 institutions reported holding it in 13F filings for Q1 2026, worth $9.69B in total; Soros Fund Management was the only superinvestor holding it.
13F holders, Q1 2026
Institutional positions in Masimo Corp as of Mar 31, 2026. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
MASI is no longer listed, so this page shows Q1 2026. 13F filings for later quarters list far fewer holders.
- Institutional holders
- 451
- +65 vs. Q4 2025
- Shares held
- 54.6M
- +4.00M (+7.9%) vs. Q4 2025
- Total value
- $9.69B
- +$3.10B (+47.2%) vs. Q4 2025
- New holders
- 136
- 140 more added
- Sold out
- 71
- 107 more reduced
6 institutions that held it in Q4 2025 haven't filed for Q1 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q4 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting MASI on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 2 | $16.2K |
| Q1 2026 | 451 | $9.69B |
| Q4 2025 | 392 | $7.32B |
| Q3 2025 | 358 | $8.31B |
| Q2 2025 | 379 | $9.69B |
| Q1 2025 | 393 | $9.03B |
| Q4 2024 | 366 | $8.51B |
| Q3 2024 | 362 | $6.74B |
| Q2 2024 | 352 | $6.26B |
| Q1 2024 | 339 | $7.79B |
| Q4 2023 | 342 | $6.00B |
| Q3 2023 | 357 | $4.19B |
| Q2 2023 | 415 | $7.57B |
| Q1 2023 | 428 | $9.43B |
| Q4 2022 | 405 | $6.58B |
| Q3 2022 | 419 | $6.55B |
| Q2 2022 | 417 | $5.81B |
| Q1 2022 | 457 | $6.69B |
| Q4 2021 | 520 | $13.6B |
| Q3 2021 | 475 | $12.5B |
| Q2 2021 | 459 | $11.1B |
| Q1 2021 | 481 | $10.3B |
Institutions, Q1 2026
Shares, value and share of portfolio for each institution holding Masimo Corp; share changes are against Q4 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| BlackRock, Inc. | 4,644,578 | $826.1M | 0.01% | −4,211,041−47.6% | Reduced |
| Politan Capital Management LP | 4,589,648 | $816.4M | 82.89% | 00.0% | Unchanged |
| Pentwater Capital Management LP | 3,176,000 | $564.9M | 4.01% | +3,176,000 | New |
| Barclays PLC | 2,743,985 | $488.1M | 0.17% | +2,685,627+4,602.0% | Added |
| HBK Investments L P | 2,576,109 | $458.2M | 5.77% | +2,576,109 | New |
| Massachusetts Financial Services Co | 2,342,790 | $416.7M | 0.14% | −321,085−12.1% | Reduced |
| Vanguard Capital Management LLC | 2,050,045 | $364.6M | 0.01% | +2,050,045 | New |
| Vanguard Portfolio Management LLC | 2,006,861 | $357.0M | 0.02% | +2,006,861 | New |
| FMR LLC | 1,450,823 | $258.1M | 0.01% | −6,413,341−81.6% | Reduced |
| State Street Corp | 1,437,724 | $255.7M | 0.01% | +22,528+1.6% | Added |
| Millennium Management LLC | 988,853 | $175.9M | 0.13% | +800,888+426.1% | Added |
| Goldman Sachs Group Inc | 984,192 | $175.1M | 0.02% | +347,494+54.6% | Added |
| Geode Capital Management, LLC | 956,736 | $170.2M | 0.01% | +2,760+0.3% | Added |
| AQR Capital Management LLC | 831,966 | $147.4M | 0.07% | −259,360−23.8% | Reduced |
| Balyasny Asset Management LLC | 770,986 | $137.1M | 0.27% | +770,986 | New |
| Morgan Stanley | 752,417 | $133.8M | 0.01% | −168,318−18.3% | Reduced |
| Davidson Kempner Capital Management LP | 585,988 | $104.2M | 1.85% | +585,988 | New |
| JPMorgan Chase & Co | 572,645 | $101.5M | 0.01% | +454,847+386.1% | Added |
| Citigroup Inc | 533,388 | $94.9M | 0.06% | +412,157+340.0% | Added |
| SG Americas Securities, LLC | 522,824 | $93.0M | 0.10% | +506,395+3,082.3% | Added |
| FIL Ltd | 482,000 | $85.7M | 0.07% | +482,000 | New |
| Vivaldi Asset Management, LLC | 479,403 | $85.3M | 4.48% | +479,403 | New |
| HSBC Holdings PLC | 473,434 | $84.3M | 0.05% | +473,434 | New |
| UBS Group AG | 468,257 | $83.3M | 0.01% | −131,017−21.9% | Reduced |
| Magnetar Financial LLC | 427,081 | $76.0M | 0.77% | +421,626+7,729.2% | Added |
| CNH Partners LLC | 416,956 | $73.9M | 1.21% | +416,956 | New |
| O'Connor Alternative Investments LLC | 412,903 | $73.4M | 3.85% | +412,903 | New |
| Neuberger Berman Group LLC | 403,309 | $71.7M | 0.05% | +398,303+7,956.5% | Added |
| Northern Trust Corp | 390,437 | $69.4M | 0.01% | +9,973+2.6% | Added |
| Squarepoint Ops LLC | 389,359 | $69.3M | 0.15% | −194,388−33.3% | Reduced |
| Charles Schwab Investment Management Inc | 386,898 | $68.8M | 0.01% | +25,002+6.9% | Added |
| Capital Research Global Investors | 359,058 | $63.9M | 0.01% | −278,836−43.7% | Reduced |
| Gotham Asset Management, LLC | 341,468 | $60.7M | 0.19% | −726−0.2% | Reduced |
| Westfield Capital Management Co LP | 341,229 | $60.7M | 0.25% | −1,180,820−77.6% | Reduced |
| Alliancebernstein L.P. | 455,354 | $59.2M | 0.02% | +401,131+739.8% | Added |
| Hudson Bay Capital Management LP | 330,679 | $58.8M | 0.35% | +330,679 | New |
| CI Private Wealth, LLC | 321,600 | $57.2M | 0.08% | −18,630−5.5% | Reduced |
| Fort Baker Capital Management LP | 312,720 | $55.6M | 4.93% | +312,720 | New |
| Highland Capital Management Fund Advisors, L.P. | 310,130 | $55.2M | 3.85% | +310,130 | New |
| Capitolis Liquid Global Markets LLC | 309,102 | $55.0M | 0.35% | +309,102 | New |
| Bank of New York Mellon Corp | 306,400 | $54.5M | 0.01% | −2,085−0.7% | Reduced |
| Qube Research & Technologies Ltd | 291,481 | $51.8M | 0.07% | −2,055−0.7% | Reduced |
| Vanguard Fiduciary Trust Co | 289,867 | $51.6M | 0.01% | +289,867 | New |
| Citadel Advisors LLC | 281,366 | $50.0M | 0.04% | +238,314+553.5% | Added |
| Whitebox Advisors LLC | 270,001 | $48.0M | 0.68% | +270,001 | New |
| HRT Financial LP | 264,837 | $47.1M | 0.12% | +172,061+185.5% | Added |
| Nuance Investments, LLC | 244,704 | $43.5M | 6.07% | +244,704 | New |
| Amundi | 243,143 | $43.2M | 0.01% | +199,283+454.4% | Added |
| Slotnik Capital, LLC | 240,300 | $42.7M | 12.70% | +240,300 | New |
| Renaissance Technologies LLC | 239,500 | $42.6M | 0.07% | +179,600+299.8% | Added |
| Polar Asset Management Partners Inc. | 232,026 | $41.3M | 0.98% | +232,026 | New |
| Bank of America Corp | 232,003 | $41.3M | 0.00% | −52,699−18.5% | Reduced |
| MUFG Securities EMEA plc | 225,400 | $40.1M | 0.60% | +225,400 | New |
| Beryl Capital Management LLC | 217,103 | $38.6M | 35.54% | +217,103 | New |
| Canada Pension Plan Investment Board | 209,500 | $37.3M | 0.02% | +171,000+444.2% | Added |
| Erste Asset Management GmbH | 200,000 | $35.5M | 0.33% | 00.0% | Unchanged |
| Water Island Capital LLC | 194,197 | $34.5M | 4.60% | +194,197 | New |
| Alpine Associates Management Inc. | 189,000 | $33.6M | 1.98% | +189,000 | New |
| American Century Companies Inc | 188,073 | $33.5M | 0.02% | +9,315+5.2% | Added |
| Arrowstreet Capital, Limited Partnership | 172,588 | $30.7M | 0.02% | +172,588 | New |
| Readystate Asset Management LP | 171,115 | $30.4M | 1.78% | +171,115 | New |
| Raymond James Financial Inc | 170,527 | $30.3M | 0.01% | −15,983−8.6% | Reduced |
| Man Group plc | 166,235 | $29.6M | 0.06% | +18,819+12.8% | Added |
| Dimensional Fund Advisors LP | 164,402 | $29.2M | 0.01% | −9,548−5.5% | Reduced |
| Glazer Capital, LLC | 157,858 | $28.1M | 0.60% | +157,858 | New |
| Woodline Partners LP | 153,234 | $27.3M | 0.10% | +153,234 | New |
| Bank of Nova Scotia | 152,584 | $27.1M | 0.05% | +147,337+2,808.0% | Added |
| Tudor Investment Corp Et Al | 143,884 | $25.6M | 0.14% | +127,642+785.9% | Added |
| Capula Management Ltd | 142,800 | $25.4M | 0.22% | +142,800 | New |
| Champlain Investment Partners, LLC | 141,284 | $25.1M | 0.32% | +141,284 | New |
| Westchester Capital Management, LLC | 138,428 | $24.6M | 1.19% | +138,428 | New |
| Grantham, Mayo, Van Otterloo & Co. LLC | 137,617 | $24.5M | 0.06% | −6,208−4.3% | Reduced |
| TIG Advisors, LLC | 135,197 | $24.0M | 1.15% | +135,197 | New |
| UBS Asset Management Americas Inc | 133,689 | $23.8M | 0.00% | +14,725+12.4% | Added |
| Rhumbline Advisers | 129,619 | $23.1M | 0.02% | +5,063+4.1% | Added |
| Gabelli Funds LLC | 126,082 | $22.4M | 0.15% | +93,382+285.6% | Added |
| GW&K Investment Management, LLC | 122,781 | $21.8M | 0.19% | +3,419+2.9% | Added |
| Sagefield Capital LP | 122,240 | $21.7M | 1.56% | +122,240 | New |
| Schonfeld Strategic Advisors LLC | 117,297 | $20.9M | 0.17% | −147,739−55.7% | Reduced |
| Winton Group Ltd | 112,783 | $20.1M | 0.70% | +112,783 | New |
| Weiss Asset Management LP | 112,600 | $20.0M | 0.37% | +112,600 | New |
| Nuveen, LLC | 111,542 | $19.8M | 0.01% | −112,526−50.2% | Reduced |
| Nomura Holdings Inc | 109,390 | $19.5M | 0.16% | +109,390 | New |
| Blackstone Group Inc. | 109,383 | $19.5M | 0.08% | +109,383 | New |
| Principal Financial Group Inc | 102,718 | $18.3M | 0.01% | +4,860+5.0% | Added |
| Soros Fund Management LLCSuperinvestorSoros Fund Management | 100,838 | $17.9M | 0.25% | +100,838 | New |
| Kryger Capital LLC | 100,589 | $17.9M | 1.27% | +100,589 | New |
| Schroder Investment Management Group | 96,179 | $17.1M | 0.01% | −379,325−79.8% | Reduced |
| Gamco Investors, Inc. Et Al | 92,000 | $16.4M | 0.16% | +9,000+10.8% | Added |
| Marshall Wace, LLP | 90,657 | $16.1M | 0.02% | −128,655−58.7% | Reduced |
| CIBRA Capital Ltd | 90,376 | $16.1M | 7.76% | +90,376 | New |
| Swiss National Bank | 90,300 | $16.1M | 0.01% | −800−0.9% | Reduced |
| Deutsche Bank AG | 89,387 | $15.9M | 0.01% | +82,651+1,227.0% | Added |
| Gabelli & Co Investment Advisers, Inc. | 88,650 | $15.8M | 2.34% | +88,650 | New |
| California Public Employees Retirement System | 77,397 | $13.8M | 0.01% | +14,038+22.2% | Added |
| Voloridge Investment Management, LLC | 70,000 | $12.5M | 0.05% | +30,443+77.0% | Added |
| Invesco Ltd. | 69,144 | $12.3M | 0.00% | −250,164−78.3% | Reduced |
| Healthcare of Ontario Pension Plan Trust Fund | 67,600 | $12.0M | 0.02% | +67,600 | New |
| Verition Fund Management LLC | 66,853 | $11.9M | 0.12% | +13,833+26.1% | Added |
| Ameriprise Financial Inc | 65,203 | $11.6M | 0.00% | −403,204−86.1% | Reduced |