Masimo Corporation
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionGabelli Funds Llc
Latest Disclosed Ownership126,082 shares
Latest Disclosed Value $ 22,426,205
Gabelli Funds Llc reports 285.57% increase in ownership of MASI / Masimo Corporation

On May 14, 2026 - Gabelli Funds Llc filed a 13F-HR form disclosing ownership of 126,082 shares of Masimo Corporation (MX:MASI) valued at $22,426,205 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 32,700 shares of Masimo Corporation. This represents a change in shares of 285.57% during the quarter.

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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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)
2026-05-14 2026-03-31 13F MASIMO EQUITY 574795100 126,082 93,382 285.57 22,426 427.42 0.1515
2026-02-05 2025-12-31 13F MASIMO EQUITY 574795100 32,700 0 0.00 4,253 -11.86 0.0288
2025-11-12 2025-09-30 13F MASIMO EQUITY 574795100 32,700 0 0.00 4,825 -12.29 0.0327
2025-08-13 2025-06-30 13F MASIMO EQUITY 574795100 32,700 -300 -0.91 5,501 0.05 0.0391
2025-05-14 2025-03-31 13F MASIMO EQUITY 574795100 33,000 0 0.00 5,498 0.79 0.0419
2025-02-13 2024-12-31 13F MASIMO EQUITY 574795100 33,000 0 0.00 5,455 23.98 0.0410
2024-11-13 2024-09-30 13F MASIMO EQUITY 574795100 33,000 0 0.00 4,400 5.85 0.0317
2024-08-13 2024-06-30 13F MASIMO EQUITY 574795100 33,000 0 0.00 4,156 -14.24 0.0316
2024-05-14 2024-03-31 13F MASIMO EQUITY 574795100 33,000 0 0.00 4,846 25.32 0.0357
2024-02-13 2023-12-31 13F MASIMO EQUITY 574795100 33,000 0 0.00 3,868 33.67 0.0298
2023-11-08 2023-09-30 13F MASIMO EQUITY 574795100 33,000 0 0.00 2,893 -46.72 0.0235
2023-08-10 2023-06-30 13F MASIMO EQUITY 574795100 33,000 0 0.00 5,430 -10.82 0.0412
2023-05-12 2023-03-31 13F MASIMO EQUITY 574795100 33,000 -200 -0.60 6,090 23.99 0.0462
2023-02-13 2022-12-31 13F MASIMO EQUITY 574795100 33,200 0 0.00 4,912 4.78 0.0382
2022-11-14 2022-09-30 13F/A-1 MASIMO CORP COM COM 574795100 33,200 0 0.00 4,687 8.05 0.0386
2022-11-10 2022-09-30 13F MASIMO CORP COM COM 574795100 33,200 0 4,687 0.0386
2022-08-12 2022-06-30 13F MASIMO CORP COM COM 574795100 33,200 -500 -1.48 4,338 -11.56 0.0333
2022-05-18 2022-03-31 13F/A-1 MASIMO CORP COM COM 574795100 33,700 -300 -0.88 4,905 -50.73 0.0322
2022-05-13 2022-03-31 13F MASIMO CORP COM COM 574795100 33,700 -300 4,905 0.0331
2022-02-11 2021-12-31 13F MASIMO CORP COM COM 574795100 34,000 -1,000 -2.86 9,955 5.07 0.0628
2021-11-12 2021-09-30 13F MASIMO CORP COM COM 574795100 35,000 -1,000 -2.78 9,475 8.56 0.0628
2021-08-13 2021-06-30 13F MASIMO CORP COM COM 574795100 36,000 -200 -0.55 8,728 4.98 0.0556
2021-05-14 2021-03-31 13F MASIMO CORP COM COM 574795100 36,200 -1,800 -4.74 8,314 -18.47 0.0557
2021-02-05 2020-12-31 13F MASIMO CORP COM COM 574795100 38,000 -2,500 -6.17 10,198 6.67 0.0726
2020-11-06 2020-09-30 13F MASIMO CORP COM COM 574795100 40,500 -4,000 -8.99 9,560 -5.78 0.0745
2020-08-13 2020-06-30 13F MASIMO CORP COM COM 574795100 44,500 -7,800 -14.91 10,146 9.53 0.0827
2020-05-14 2020-03-31 13F MASIMO CORP COM COM 574795100 52,300 -11,200 -17.64 9,263 -7.71 0.0825
2020-02-14 2019-12-31 13F MASIMO CORP COM COM 574795100 63,500 -14,500 -18.59 10,037 -13.52 0.0649
2019-11-01 2019-09-30 13F MASIMO CORP COM COM 574795100 78,000 -13,500 -14.75 11,606 -14.77 0.0767
2019-08-02 2019-06-30 13F MASIMO CORP COM COM 574795100 91,500 -8,500 -8.50 13,617 -1.53 0.0874
2019-05-02 2019-03-31 13F MASIMO CORP COM COM 574795100 100,000 -7,000 -6.54 13,828 20.36 0.0869
2019-01-30 2018-12-31 13F MASIMO CORP COM COM 574795100 107,000 0 0.00 11,489 -13.79 0.0788
2018-11-02 2018-09-30 13F MASIMO CORP COM COM 574795100 107,000 -3,000 -2.73 13,326 24.06 0.0765
2018-08-10 2018-06-30 13F MASIMO CORP COM COM 574795100 110,000 -5,000 -4.35 10,742 6.21 0.0636
2018-05-09 2018-03-31 13F MASIMO CORP COM COM 574795100 115,000 0 0.00 10,114 3.71 0.0603
2018-02-02 2017-12-31 13F MASIMO CORP COM COM 574795100 115,000 -2,000 -1.71 9,752 -3.71 0.0562
2017-11-01 2017-09-30 13F MASIMO CORP COM COM 574795100 117,000 -1,000 -0.85 10,128 -5.86 0.0580
2017-08-03 2017-06-30 13F MASIMO CORP COM COM 574795100 118,000 -2,000 -1.67 10,759 -3.86 0.0639
2017-05-04 2017-03-31 13F MASIMO CORP COM COM 574795100 120,000 -2,000 -1.64 11,191 36.09 0.0660
2017-02-10 2016-12-31 13F MASIMO CORP COM COM 574795100 122,000 0 0.00 8,223 13.30 0.0487
2016-11-10 2016-09-30 13F MASIMO CORP COM COM 574795100 122,000 0 0.00 7,258 13.28 0.0431
2016-08-04 2016-06-30 13F MASIMO CORP COM COM 574795100 122,000 0 0.00 6,407 25.53 0.0378
2016-05-05 2016-03-31 13F MASIMO CORP COM COM 574795100 122,000 0 0.00 5,104 0.79 0.0308
2016-02-05 2015-12-31 13F MASIMO CORP COM COM 574795100 122,000 0 0.00 5,064 7.65 0.0307
2015-10-23 2015-09-30 13F MASIMO CORP COM COM 574795100 122,000 0 0.00 4,704 -0.47 0.0280
2015-08-05 2015-06-30 13F MASIMO CORP COM COM 574795100 122,000 0 0.00 4,726 17.45 0.0247
2015-05-01 2015-03-31 13F MASIMO CORP COM COM 574795100 122,000 4,000 3.39 4,024 29.47 0.0204
2015-02-05 2014-12-31 13F MASIMO CORP COM COM 574795100 118,000 13,000 12.38 3,108 39.12 0.0151
2014-10-30 2014-09-30 13F MASIMO CORP COM COM 574795100 105,000 0 0.00 2,234 -9.85 0.0113
2014-08-06 2014-06-30 13F MASIMO CORP COM COM 574795100 105,000 30,000 40.00 2,478 21.00 0.0122
2014-05-16 2014-03-31 13F/A-1 MASIMO CORP COM COM 574795100 75,000 34,000 82.93 2,048 70.95 0.0106
2014-05-02 2014-03-31 13F MASIMO CORP COM COM 574795100 75,000 2,048
2014-02-07 2013-12-31 13F MASIMO CORP COM COM 574795100 41,000 26,000 173.33 1,198 199.50 0.0064
2013-11-07 2013-09-30 13F MASIMO CORP COM COM 574795100 15,000 -35,000 -70.00 400 -62.26 0.0023
2013-08-02 2013-06-30 13F/A-1 MASIMO CORP COM COM 574795100 50,000 50,000 1,060 0.0064
2013-08-01 2013-06-30 13F MASIMO CORP COM COM 574795100 50,000 1,060 0.0064
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.