馬西莫公司
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionMillennium Management Llc
ManagerIsrael Englander
Latest Disclosed Ownership988,853 shares
Latest Disclosed Value $ 175,887,283
Millennium Management Llc ownership in MASI / Masimo Corporation

On May 15, 2026 - Millennium Management Llc filed a 13F-HR form disclosing ownership of 988,853 shares of Masimo Corporation (MX:MASI) valued at $175,887,283 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 187,965 shares of Masimo Corporation. This represents a change in shares of 426.08% during the quarter.

Millennium Management Llc has a history of taking positions in derivatives of the underlying security (MASI) in the form of stock options. The firm currently holds call options representing 288,600 of underlying shares valued at $51,333,282 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:MASI / Masimo Corporation Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F MASIMO COM 574795100 988,853 800,888 426.08 175,887 619.49 0.0732
2026-02-17 2025-12-31 13F MASIMO COM 574795100 187,965 171,834 1,065.24 24,447 927.14 0.0103
2025-11-14 2025-09-30 13F MASIMO COM 574795100 16,131 12,224 312.87 2,380 262.25 0.0010
2025-08-14 2025-06-30 13F MASIMO COM 574795100 3,907 -130,899 -97.10 657 -97.07 0.0003
2025-05-15 2025-03-31 13F MASIMO COM 574795100 134,806 -273,252 -66.96 22,459 -66.70 0.0120
2025-02-14 2024-12-31 13F MASIMO COM 574795100 408,058 378,805 1,294.93 67,452 1,629.51 0.0330
2024-11-14 2024-09-30 13F MASIMO COM 574795100 29,253 -724,490 -96.12 3,900 -95.89 0.0018
2024-08-14 2024-06-30 13F MASIMO COM 574795100 753,743 406,727 117.21 94,926 86.28 0.0440
2024-05-15 2024-03-31 13F MASIMO COM 574795100 347,016 150,556 76.63 50,959 121.30 0.0218
2024-02-14 2023-12-31 13F MASIMO COM 574795100 196,460 -44,741 -18.55 23,027 8.89 0.0100
2023-11-14 2023-09-30 13F MASIMO COM 574795100 241,201 22,219 10.15 21,149 -41.31 0.0107
2023-08-14 2023-06-30 13F MASIMO COM 574795100 218,982 -176,571 -44.64 36,033 -50.64 0.0178
2023-05-15 2023-03-31 13F MASIMO COM 574795100 395,553 204,617 107.17 72,995 158.40 0.0419
2023-02-14 2022-12-31 13F MASIMO COM 574795100 190,936 -357,690 -65.20 28,249 -63.52 0.0156
2022-11-14 2022-09-30 13F MASIMO COM 574795100 548,626 -173,533 -24.03 77,444 -17.93 0.0458
2022-08-15 2022-06-30 13F MASIMO COM 574795100 722,159 -242,534 -25.14 94,365 -32.79 0.0585
2022-05-16 2022-03-31 13F MASIMO COM 574795100 964,693 723,950 300.71 140,401 99.19 0.0744
2022-02-14 2021-12-31 13F MASIMO COM 574795100 240,743 215,751 863.28 70,485 941.75 0.0358
2021-11-15 2021-09-30 13F MASIMO COM 574795100 24,992 14,541 139.14 6,766 167.01 0.0041
2021-08-16 2021-06-30 13F MASIMO COM 574795100 10,451 -47,089 -81.84 2,534 -80.82 0.0016
2021-05-17 2021-03-31 13F MASIMO COM 574795100 57,540 57,540 13,215 0.0095
2020-11-16 2020-09-30 13F MASIMO COM 574795100 0 -61,912 -100.00 0 -100.00
2020-08-14 2020-06-30 13F MASIMO COM 574795100 61,912 -30,306 -32.86 14,115 -13.59 0.0193
2020-05-14 2020-03-31 13F MASIMO COM 574795100 92,218 87,641 1,914.81 16,334 2,159.20 0.0367
2020-02-14 2019-12-31 13F MASIMO COM 574795100 4,577 -10,020 -68.64 723 -66.70 0.0009
2019-11-14 2019-09-30 13F MASIMO COM 574795100 14,597 11,626 391.32 2,171 391.18 0.0034
2019-08-15 2019-06-30 13F/A-1 MASIMO COM 574795100 2,971 -83,606 -96.57 442 -96.31 0.0007
2019-08-14 2019-06-30 13F MIMECAST ORD SHS 574795100 462,157 375,580 21,587
2019-05-14 2019-03-31 13F MASIMO COM 574795100 86,577 -367,596 -80.94 11,972 -75.45 0.0179
2019-02-15 2018-12-31 13F/A-1 MASIMO COM 574795100 454,173 -650,185 -58.87 48,765 -64.54 0.0760
2019-02-14 2018-12-31 13F MASIMO COM 574795100 454,173 48,765
2018-11-14 2018-09-30 13F MASIMO COM 574795100 1,104,358 192,905 21.16 137,537 54.53 0.1686
2018-08-14 2018-06-30 13F MASIMO COM 574795100 911,453 431,669 89.97 89,003 110.92 0.1161
2018-05-15 2018-03-31 13F MASIMO COM 574795100 479,784 356,708 289.83 42,197 304.30 0.0563
2018-02-14 2017-12-31 13F MASIMO COM 574795100 123,076 -132,526 -51.85 10,437 -52.83 0.0144
2017-11-14 2017-09-30 13F MASIMO COM 574795100 255,602 242,547 1,857.89 22,125 1,759.24 0.0337
2017-08-14 2017-06-30 13F MASIMO COM 574795100 13,055 -145,785 -91.78 1,190 -91.97 0.0021
2017-05-15 2017-03-31 13F MASIMO COM 574795100 158,840 68,442 75.71 14,813 143.12 0.0271
2017-02-14 2016-12-31 13F MASIMO COM 574795100 90,398 -15,004 -14.24 6,093 -2.82 0.0128
2016-11-14 2016-09-30 13F MASIMO COM 574795100 105,402 -139,050 -56.88 6,270 -51.16 0.0105
2016-08-15 2016-06-30 13F MASIMO COM 574795100 244,452 178,470 270.48 12,837 364.94 0.0294
2016-05-16 2016-03-31 13F MASIMO COM 574795100 65,982 -107,054 -61.87 2,761 -61.56 0.0069
2016-02-16 2015-12-31 13F MASIMO COM 574795100 173,036 157,092 985.27 7,183 1,067.97 0.0151
2015-11-16 2015-09-30 13F MASIMO COM 574795100 15,944 -4,691 -22.73 615 -23.03 0.0012
2015-08-14 2015-06-30 13F MASIMO COM 574795100 20,635 -227,504 -91.68 799 -90.24 0.0015
2015-05-15 2015-03-31 13F MASIMO COM 574795100 248,139 180,044 264.40 8,184 356.19 0.0152
2015-02-17 2014-12-31 13F MASIMO COM 574795100 68,095 -317,306 -82.33 1,794 -78.12 0.0038
2014-11-14 2014-09-30 13F MASIMO COM 574795100 385,401 97,248 33.75 8,201 20.60 0.0207
2014-08-14 2014-06-30 13F MASIMO COM 574795100 288,153 268,153 1,340.77 6,800 1,145.42 0.0188
2014-05-15 2014-03-31 13F MASIMO COM 574795100 20,000 -142,451 -87.69 546 -88.50 0.0016
2014-02-14 2013-12-31 13F MASIMO COM 574795100 162,451 154,851 2,037.51 4,748 2,250.50 0.0150
2013-11-14 2013-09-30 13F MASIMO COM 574795100 7,600 -169,506 -95.71 202 -94.62 0.0007
2013-08-14 2013-06-30 13F MASIMO COM 574795100 177,106 177,106 3,755 0.0115
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F MASIMO COM Call 288,600 51,333 n/a n/a n/a
2025-05-15 2025-03-31 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F MASIMO COM Call 25,000 -17.76 4,132 1.95 n/a n/a n/a
2024-11-14 2024-09-30 13F MASIMO COM Call 30,400 4,053 n/a n/a n/a
2024-05-15 2024-03-31 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-02-14 2023-12-31 13F MASIMO COM Call 20,000 -79.80 2,344 -73.00 n/a n/a n/a
2023-11-14 2023-09-30 13F MASIMO COM Call 99,000 560.00 8,680 251.70 n/a n/a n/a
2023-08-14 2023-06-30 13F MASIMO COM Call 15,000 2,468 n/a n/a n/a
2023-05-15 2023-03-31 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-02-14 2022-12-31 13F MASIMO COM Call 15,000 650.00 2,219 686.88 n/a n/a n/a
2022-11-14 2022-09-30 13F MASIMO COM Call 2,000 -80.58 282 -79.05 n/a n/a n/a
2022-08-15 2022-06-30 13F MASIMO COM Call 10,300 -73.18 1,346 -75.92 n/a n/a n/a
2022-05-16 2022-03-31 13F MASIMO COM Call 38,400 92.00 5,589 -4.56 n/a n/a n/a
2022-02-14 2021-12-31 13F MASIMO COM Call 20,000 -66.67 5,856 -63.95 n/a n/a n/a
2021-11-15 2021-09-30 13F MASIMO COM Call 60,000 50.00 16,243 67.49 n/a n/a n/a
2021-08-16 2021-06-30 13F MASIMO COM Call 40,000 166.67 9,698 181.51 n/a n/a n/a
2021-05-17 2021-03-31 13F MASIMO COM Call 15,000 3,445 n/a n/a n/a
2021-02-16 2020-12-31 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-11-16 2020-09-30 13F MASIMO COM Call 40,000 166.67 9,442 176.08 n/a n/a n/a
2020-08-14 2020-06-30 13F MASIMO COM Call 15,000 15.38 3,420 48.50 n/a n/a n/a
2020-05-14 2020-03-31 13F MASIMO COM Call 13,000 62.50 2,303 82.20 n/a n/a n/a
2020-02-14 2019-12-31 13F MASIMO COM Call 8,000 1,264 n/a n/a n/a
2019-05-14 2019-03-31 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-02-15 2018-12-31 13F/A MASIMO COM Call 20,000 2,147 n/a n/a n/a
2019-02-14 2018-12-31 13F MASIMO COM Call 20,000 2,147 n/a n/a n/a
2018-08-14 2018-06-30 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-05-15 2018-03-31 13F MASIMO COM Call 10,000 0.00 880 3.77 n/a n/a n/a
2018-02-14 2017-12-31 13F MASIMO COM Call 10,000 100.00 848 95.84 n/a n/a n/a
2017-11-14 2017-09-30 13F MASIMO COM Call 5,000 433 n/a n/a n/a
2017-05-15 2017-03-31 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-02-14 2016-12-31 13F MASIMO COM Call 50,000 400.00 3,370 466.39 n/a n/a n/a
2016-11-14 2016-09-30 13F MASIMO COM Call 10,000 595 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-08-14 2025-06-30 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F MASIMO COM Put 10,000 1,666 n/a n/a n/a
2025-02-14 2024-12-31 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2024-11-14 2024-09-30 13F MASIMO COM Put 2,700 17.39 360 24.22 n/a n/a n/a
2024-08-14 2024-06-30 13F MASIMO COM Put 2,300 -56.60 290 -62.85 n/a n/a n/a
2024-05-15 2024-03-31 13F MASIMO COM Put 5,300 778 n/a n/a n/a
2024-02-14 2023-12-31 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-14 2023-09-30 13F MASIMO COM Put 45,400 3,981 n/a n/a n/a
2023-08-14 2023-06-30 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-05-15 2023-03-31 13F MASIMO COM Put 7,000 1,292 n/a n/a n/a
2023-02-14 2022-12-31 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-14 2022-09-30 13F MASIMO COM Put 7,000 -80.17 988 -78.58 n/a n/a n/a
2022-08-15 2022-06-30 13F MASIMO COM Put 35,300 145.14 4,613 120.09 n/a n/a n/a
2022-05-16 2022-03-31 13F MASIMO COM Put 14,400 -64.00 2,096 -82.10 n/a n/a n/a
2022-02-14 2021-12-31 13F MASIMO COM Put 40,000 700.00 11,711 764.92 n/a n/a n/a
2021-11-15 2021-09-30 13F MASIMO COM Put 5,000 -75.00 1,354 -72.08 n/a n/a n/a
2021-08-16 2021-06-30 13F MASIMO COM Put 20,000 300.00 4,849 322.39 n/a n/a n/a
2021-05-17 2021-03-31 13F MASIMO COM Put 5,000 1,148 n/a n/a n/a
2020-08-14 2020-06-30 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-14 2020-03-31 13F MASIMO COM Put 5,000 886 n/a n/a n/a
2020-02-14 2019-12-31 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F MASIMO COM Put 2,000 297 n/a n/a n/a
2019-08-15 2019-06-30 13F/A MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-05-14 2019-03-31 13F MASIMO COM Put 30,000 4,148 n/a n/a n/a
2018-11-14 2018-09-30 13F MASIMO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-08-14 2018-06-30 13F MASIMO COM Put 15,000 -70.00 1,465 -66.69 n/a n/a n/a
2018-05-15 2018-03-31 13F MASIMO COM Put 50,000 4,398 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.