Masimo Corporation
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionNorthwestern Mutual Wealth Management Co
Latest Disclosed Ownership52 shares
Latest Disclosed Value $ 9,249
Northwestern Mutual Wealth Management Co reports 3.70% decrease in ownership of MASI / Masimo Corporation

On May 7, 2026 - Northwestern Mutual Wealth Management Co filed a 13F-HR form disclosing ownership of 52 shares of Masimo Corporation (MX:MASI) valued at $9,249 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on February 10, 2026 disclosing 54 shares of Masimo Corporation. This represents a change in shares of -3.70% 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)
2026-05-07 2026-03-31 13F MASIMO COM 574795100 52 -2 -3.70 9 28.57 0.0000
2026-02-10 2025-12-31 13F/A-1 MASIMO COM 574795100 54 -99 -64.71 7 -68.18 0.0000
2026-02-05 2025-12-31 13F MASIMO COM 574795100 1,714 1,561 49 0.0000
2025-11-14 2025-09-30 13F MASIMO COM 574795100 153 1 0.66 23 -12.00 0.0000
2025-08-13 2025-06-30 13F MASIMO COM 574795100 152 0 0.00 26 0.00 0.0000
2025-05-14 2025-03-31 13F MASIMO COM 574795100 152 0 0.00 25 0.00 0.0000
2025-02-11 2024-12-31 13F MASIMO COM 574795100 152 -1,508 -90.84 25 -88.69 0.0000
2024-11-12 2024-09-30 13F MASIMO COM 574795100 1,660 1,310 374.29 221 402.27 0.0002
2024-08-16 2024-06-30 13F MASIMO COM 574795100 350 200 133.33 44 100.00 0.0000
2024-05-15 2024-03-31 13F MASIMO COM 574795100 150 0 0.00 22 29.41 0.0000
2024-02-13 2023-12-31 13F MASIMO COM 574795100 150 -50 -25.00 18 0.00 0.0000
2023-11-14 2023-09-30 13F MASIMO COM 574795100 200 -40 -16.67 18 -56.41 0.0000
2023-08-14 2023-06-30 13F MASIMO COM 574795100 240 35 17.07 39 5.41 0.0001
2023-05-15 2023-03-31 13F MASIMO COM 574795100 205 -26 -11.26 38 8.82 0.0001
2023-02-21 2022-12-31 13F MASIMO COM 574795100 231 -421 -64.57 34 -63.04 0.0001
2022-11-14 2022-09-30 13F MASIMO COM 574795100 652 -165 -20.20 92 -14.02 0.0002
2022-08-04 2022-06-30 13F MASIMO COM 574795100 817 190 30.30 107 16.30 0.0002
2022-05-09 2022-03-31 13F MASIMO COM 574795100 627 -96 -13.28 92 -56.60 0.0001
2022-02-03 2021-12-31 13F MASIMO COM 574795100 723 -109 -13.10 212 -6.19 0.0003
2021-11-15 2021-09-30 13F MASIMO COM 574795100 832 -287 -25.65 226 -16.61 0.0004
2021-08-13 2021-06-30 13F MASIMO COM 574795100 1,119 -157 -12.30 271 -7.51 0.0005
2021-05-14 2021-03-31 13F MASIMO COM 574795100 1,276 -361 -22.05 293 -33.26 0.0006
2021-02-12 2020-12-31 13F MASIMO COM 574795100 1,637 39 2.44 439 16.45 0.0010
2020-11-13 2020-09-30 13F MASIMO COM 574795100 1,598 311 24.16 377 28.67 0.0010
2020-08-14 2020-06-30 13F MASIMO COM 574795100 1,287 45 3.62 293 33.18 0.0009
2020-05-08 2020-03-31 13F MASIMO COM 574795100 1,242 5 0.40 220 12.24 0.0008
2020-02-13 2019-12-31 13F MASIMO COM 574795100 1,237 0 0.00 196 6.52 0.0007
2019-11-12 2019-09-30 13F MASIMO COM 574795100 1,237 -34 -2.68 184 -2.65 0.0007
2019-08-12 2019-06-30 13F MASIMO COM 574795100 1,271 0 0.00 189 7.39 0.0008
2019-05-10 2019-03-31 13F MASIMO COM 574795100 1,271 50 4.10 176 34.35 0.0008
2019-02-12 2018-12-31 13F MASIMO COM 574795100 1,221 0 0.00 131 -13.82 0.0007
2018-11-01 2018-09-30 13F MASIMO COM 574795100 1,221 100 8.92 152 39.45 0.0008
2018-08-10 2018-06-30 13F MASIMO COM 574795100 1,121 1,121 109 0.0006
2018-05-14 2018-03-31 13F MASIMO COM 574795100 0 -55 -100.00 0 -100.00
2018-01-31 2017-12-31 13F MASIMO COM 574795100 55 40 266.67 5 400.00 0.0000
2017-11-07 2017-09-30 13F MASIMO COM 574795100 15 15 1 0.0000
2017-05-09 2017-03-31 13F MASIMO COM 574795100 0 -71 -100.00 0 -100.00
2017-02-15 2016-12-31 13F MASIMO COM 574795100 71 1 1.43 5 25.00 0.0001
2016-11-14 2016-09-30 13F MASIMO COM 574795100 70 0 0.00 4 0.00 0.0001
2016-08-29 2016-06-30 13F MASIMO COM 574795100 70 70 0.00 4 0.0001
2016-05-16 2016-03-31 13F MASIMO COM 574795100 0 0 0 0.0000
2016-02-16 2015-12-31 13F MASIMO COM 574795100 0 -14 -100.00 0 -100.00
2015-11-16 2015-09-30 13F MASIMO COM 574795100 14 13 1,300.00 1 -66.67 0.0000
2015-09-30 2015-06-30 13F/A-1 MASIMO COM 574795100 1 -90 -98.90 0 -100.00
2015-08-14 2015-06-30 13F MASIMO COM 574795100 91 3
2015-05-15 2015-03-31 13F MASIMO COM 574795100 91 91 -99.55 3 -99.30 0.0001
2013-11-14 2013-09-30 13F MASIMO COM 574795100 0 -20,110 -100.00 0 -100.00
2013-08-14 2013-06-30 13F MASIMO COM 574795100 20,110 20,110 426 0.0047
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.