Masimo Corporation
US ˙ NasdaqGS ˙ US5747951003

SecurityMASI / Masimo Corporation
InstitutionNatixis
Latest Disclosed Ownership25,495 shares
Latest Disclosed Value $ 4,534,796
Natixis reports 1,015.27% increase in ownership of MASI / Masimo Corporation

On May 14, 2026 - Natixis filed a 13F-HR form disclosing ownership of 25,495 shares of Masimo Corporation (US:MASI) valued at $4,534,796 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 2,286 shares of Masimo Corporation. This represents a change in shares of 1,015.27% during the quarter. The current value of the position is $4,557,996 USD.

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 COM 574795100 25,495 23,209 1,015.27 4,535 1,426.60 0.0147
2026-02-13 2025-12-31 13F MASIMO COM 574795100 2,286 2,286 297 0.0011
2025-11-14 2025-09-30 13F MASIMO COM 574795100 0 -45,648 -100.00 0 -100.00
2025-08-13 2025-06-30 13F MASIMO COM 574795100 45,648 45,648 7,679 0.0340
2025-07-18 2025-03-31 13F/A-1 MASIMO COM 574795100 0 -181 -100.00 0 -100.00
2025-05-14 2025-03-31 13F MASIMO COM 574795100 0 0
2025-02-13 2024-12-31 13F MASIMO COM 574795100 181 -14,205 -98.74 30 -98.49 0.0002
2024-11-13 2024-09-30 13F MASIMO COM 574795100 14,386 -91,430 -86.40 1,918 -85.61 0.0108
2024-08-13 2024-06-30 13F MASIMO COM 574795100 105,816 105,816 13,326 0.0763
2023-11-14 2023-09-30 13F MASIMO COM 574795100 0 -120 -100.00 0 -100.00
2023-08-11 2023-06-30 13F MASIMO COM 574795100 120 119 11,900.00 20 0.0002
2023-05-12 2023-03-31 13F MASIMO COM 574795100 1 0 0.00 0 0.0000
2023-02-24 2022-12-31 13F/A-1 MASIMO COM 574795100 1 1 0 0.0000
2022-11-14 2022-09-30 13F Masimo COM 574795100 0 -156,119 -100.00 0 -100.00
2022-08-12 2022-06-30 13F Masimo COM 574795100 156,119 156,119 20,400 0.0739
2022-05-13 2022-03-31 13F MASIMO COM 574795100 0 -11,910 -100.00 0 -100.00
2022-02-14 2021-12-31 13F MASIMO COM 574795100 11,910 8,910 297.00 3,487 329.43 0.0119
2021-11-12 2021-09-30 13F MASIMO COM 574795100 3,000 3,000 812 0.0028
2021-08-13 2021-06-30 13F MASIMO CO 574795100 0 -2,013 -100.00 0 -100.00
2021-05-14 2021-03-31 13F MASIMO CO 574795100 2,013 -11,416 -85.01 462 -87.18 0.0015
2021-02-12 2020-12-31 13F MASIMO COM 574795100 13,429 13,429 3,604 0.0131
2020-02-14 2019-12-31 13F MASIMO COM 574795100 0 -26,507 -100.00 0 -100.00
2019-11-13 2019-09-30 13F MASIMO COM 574795100 26,507 -156,415 -85.51 3,944 -85.51 0.0254
2019-08-13 2019-06-30 13F MASIMO COM 574795100 182,922 75,626 70.48 27,222 85.76 0.2152
2019-05-15 2019-03-31 13F MASIMO COM 574795100 107,296 12,327 12.98 14,654 43.71 0.0922
2019-02-14 2018-12-31 13F/A-1 MASIMO COM 574795100 94,969 -34,732 -26.78 10,197 -36.87 0.0840
2019-02-14 2018-12-31 13F MASIMO COM 574795100 94,969 -34,732 10,197
2018-11-14 2018-09-30 13F MASIMO COM 574795100 129,701 129,701 16,153 0.0934
2018-08-14 2018-06-30 13F MASIMO COM 574795100 0 -3,613 -100.00 0 -100.00
2018-05-15 2018-03-31 13F MASIMO COM 574795100 3,613 -192 -5.05 318 -1.55 0.0020
2018-02-14 2017-12-31 13F MASIMO COM 574795100 3,805 -5,014 -56.85 323 -57.67 0.0025
2017-11-14 2017-09-30 13F MASIMO COM 574795100 8,819 5,361 155.03 763 142.22 0.0070
2017-08-14 2017-06-30 13F MASIMO COM 574795100 3,458 -893 -20.52 315 -22.41 0.0036
2017-05-15 2017-03-31 13F MASIMO COM 574795100 4,351 -348 -7.41 406 28.08 0.0051
2017-02-14 2016-12-31 13F MASIMO COM 574795100 4,699 4,699 317 0.0033
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.