Masimo Corporation
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionRockefeller Capital Management L.P.
Latest Disclosed Ownership7,970 shares
Latest Disclosed Value $ 1,417,625
Rockefeller Capital Management L.P. reports 90.78% decrease in ownership of MASI / Masimo Corporation

On May 14, 2026 - Rockefeller Capital Management L.P. filed a 13F-HR form disclosing ownership of 7,970 shares of Masimo Corporation (MX:MASI) valued at $1,417,625 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on March 16, 2026 disclosing 86,411 shares of Masimo Corporation. This represents a change in shares of -90.78% 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 COM 574795100 7,970 -78,441 -90.78 1,418 -87.39 0.0025
2026-03-16 2025-12-31 13F/A-1 MASIMO COM 574795100 86,411 -61,017 -41.39 11,239 -48.34 0.0202
2026-02-14 2025-12-31 13F MASIMO COM 574795100 86,411 -61,017 11,239 0.0103
2025-11-14 2025-09-30 13F MASIMO COM 574795100 147,428 31,802 27.50 21,753 11.84 0.0426
2025-08-14 2025-06-30 13F/A-1 MASIMO COM 574795100 115,626 -1,700 -1.45 19,451 -0.49 0.0427
2025-05-14 2025-03-31 13F MASIMO COM 574795100 117,326 26,425 29.07 19,547 30.12 0.0482
2025-02-13 2024-12-31 13F MASIMO COM 574795100 90,901 -46,492 -33.84 15,022 -18.01 0.0389
2024-11-14 2024-09-30 13F MASIMO COM 574795100 137,393 5,541 4.20 18,321 10.31 0.0493
2024-08-12 2024-06-30 13F MASIMO COM 574795100 131,852 15,179 13.01 16,610 -3.06 0.0472
2024-05-14 2024-03-31 13F MASIMO COM 574795100 116,673 -11,418 -8.91 17,133 14.12 0.0500
2024-02-14 2023-12-31 13F MASIMO COM 574795100 128,091 -5,628 -4.21 15,014 28.05 0.0502
2023-11-14 2023-09-30 13F MASIMO COM 574795100 133,719 -18,290 -12.03 11,724 -53.13 0.0452
2023-08-14 2023-06-30 13F MASIMO COM 574795100 152,009 -7,717 -4.83 25,013 86,151.72 0.0969
2023-05-16 2023-03-31 13F MASIMO COM 574795100 159,726 147,839 1,243.70 29 -98.35 0.1268
2023-03-06 2022-12-31 13F MASIMO COM 574795100 11,887 -126,326 -91.40 1,758 -90.99 0.0088
2022-11-02 2022-09-30 13F MASIMO COM 574795100 138,213 -6,695 -4.62 19,508 3.03 0.1008
2022-08-12 2022-06-30 13F MASIMO COM 574795100 144,908 -364 -0.25 18,934 -10.44 0.1006
2022-05-13 2022-03-31 13F MASIMO COM 574795100 145,272 829 0.57 21,142 -50.00 0.1020
2022-02-14 2021-12-31 13F MASIMO COM 574795100 144,443 -1,050 -0.72 42,288 7.37 0.1973
2021-11-12 2021-09-30 13F MASIMO COM 574795100 145,493 731 0.50 39,385 12.22 0.2069
2021-08-10 2021-06-30 13F MASIMO COM 574795100 144,762 -4,972 -3.32 35,096 2.06 0.1977
2021-05-11 2021-03-31 13F MASIMO COM 574795100 149,734 -841 -0.56 34,387 -14.91 0.2327
2021-02-12 2020-12-31 13F MASIMO COM 574795100 150,575 -16,027 -9.62 40,411 2.76 0.3061
2020-11-13 2020-09-30 13F MASIMO COM 574795100 166,602 76 0.05 39,327 3.58 0.3684
2020-08-12 2020-06-30 13F MASIMO COM 574795100 166,526 -4,990 -2.91 37,966 24.97 0.3973
2020-05-12 2020-03-31 13F MASIMO COM 574795100 171,516 -63,834 -27.12 30,379 -18.33 0.3985
2020-02-07 2019-12-31 13F MASIMO COM 574795100 235,350 706 0.30 37,199 6.55 0.4638
2019-11-12 2019-09-30 13F MASIMO COM 574795100 234,644 -15,194 -6.08 34,913 -6.10 0.4736
2019-08-09 2019-06-30 13F MASIMO COM 574795100 249,838 -25,706 -9.33 37,181 -2.42 0.5184
2019-05-10 2019-03-31 13F MASIMO COM 574795100 275,544 -40,392 -12.78 38,102 12.32 0.5431
2019-02-12 2018-12-31 13F MASIMO COM 574795100 315,936 -5,029 -1.57 33,922 -15.14 0.5945
2018-11-02 2018-09-30 13F Masimo Common 574795100 320,965 -6,162 -1.88 39,973 25.13 0.6068
2018-07-31 2018-06-30 13F Masimo Common 574795100 327,127 -13,743 -4.03 31,944 6.55 0.5202
2018-05-09 2018-03-31 13F Masimo Common 574795100 340,870 340,870 29,980 0.4954
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.