馬西莫公司
US ˙ NasdaqGS ˙ US5747951003

SecurityMASI / Masimo Corporation
InstitutionBrown Advisory Inc
Latest Disclosed Ownership14,734 shares
Latest Disclosed Value $ 2,620,741
Brown Advisory Inc reports 0.81% decrease in ownership of MASI / Masimo Corporation

On May 15, 2026 - Brown Advisory Inc filed a 13F-HR form disclosing ownership of 14,734 shares of Masimo Corporation (US:MASI) valued at $2,620,737 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 14,854 shares of Masimo Corporation. This represents a change in shares of -0.81% during the quarter. The current value of the position is $2,635,913 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)
2026-05-15 2026-03-31 13F MASIMO COM 574795100 14,734 -120 -0.81 2,621 35.68 0.0019
2026-02-13 2025-12-31 13F MASIMO COM 574795100 14,854 -679 -4.37 1,932 -15.71 0.0027
2025-11-14 2025-09-30 13F MASIMO COM 574795100 15,533 1 0.01 2,292 -12.29 0.0030
2025-08-13 2025-06-30 13F MASIMO COM 574795100 15,532 44 0.28 2,613 1.24 0.0034
2025-04-30 2025-03-31 13F MASIMO COM 574795100 15,488 -33 -0.21 2,580 0.58 0.0037
2025-02-14 2024-12-31 13F MASIMO COM 574795100 15,521 -1,930 -11.06 2,566 10.28 0.0033
2024-11-13 2024-09-30 13F MASIMO COM 574795100 17,451 -120 -0.68 2,327 5.15 0.0029
2024-08-14 2024-06-30 13F MASIMO COM 574795100 17,571 0 0.00 2,213 -14.26 0.0029
2024-04-24 2024-03-31 13F MASIMO COM 574795100 17,571 27 0.15 2,580 25.49 0.0034
2024-02-08 2023-12-31 13F MASIMO COM 574795100 17,544 -63 -0.36 2,056 33.25 0.0029
2023-10-25 2023-09-30 13F MASIMO COM 574795100 17,607 -112 -0.63 1,544 -47.07 0.0025
2023-07-31 2023-06-30 13F MASIMO COM 574795100 17,719 -200 -1.12 2,916 -11.83 0.0046
2023-05-08 2023-03-31 13F MASIMO COM 574795100 17,919 -752 -4.03 3,307 19.70 0.0056
2023-02-13 2022-12-31 13F MASIMO COM 574795100 18,671 2 0.01 2,762 4.82 0.0051
2022-11-14 2022-09-30 13F MASIMO COM 574795100 18,669 3,127 20.12 2,635 29.74 0.0051
2022-11-14 2022-06-30 13F/A-2 MASIMO COM 574795100 15,542 5,630 56.80 2,031 40.85 0.0038
2022-09-13 2022-06-30 13F/A-1 MASIMO COM 574795100 15,542 5,575 2,031 0.0035
2022-08-02 2022-06-30 13F MASIMO COM 574795100 16,298 6,323 2,850 0.0019
2022-11-14 2022-03-31 13F/A-2 MASIMO COM 574795100 9,912 4,201 73.56 1,442 -13.81 0.0021
2022-09-13 2022-03-31 13F/A-1 MASIMO COM 574795100 9,967 4,256 1,450 0.0020
2022-05-09 2022-03-31 13F MASIMO COM 574795100 9,975 4,264 2,106 0.0029
2022-01-27 2021-12-31 13F MASIMO COM 574795100 5,711 647 12.78 1,673 22.12 0.0021
2021-11-12 2021-09-30 13F MASIMO COM 574795100 5,064 -505 -9.07 1,370 1.48 0.0020
2021-07-29 2021-06-30 13F MASIMO COM 574795100 5,569 -139 -2.44 1,350 2.97 0.0020
2021-05-14 2021-03-31 13F MASIMO COM 574795100 5,708 621 12.21 1,311 -4.03 0.0022
2021-02-12 2020-12-31 13F MASIMO COM 574795100 5,087 0 0.00 1,366 13.74 0.0024
2020-11-16 2020-09-30 13F MASIMO COM 574795100 5,087 0 0.00 1,201 3.53 0.0025
2020-08-14 2020-06-30 13F MASIMO COM 574795100 5,087 -900 -15.03 1,160 9.33 0.0027
2020-05-15 2020-03-31 13F MASIMO COM 574795100 5,987 0 0.00 1,061 12.16 0.0033
2020-02-14 2019-12-31 13F MASIMO COM 574795100 5,987 -26 -0.43 946 5.70 0.0024
2019-11-14 2019-09-30 13F MASIMO COM 574795100 6,013 0 0.00 895 0.00 0.0025
2019-08-12 2019-06-30 13F MASIMO COM 574795100 6,013 -4,875 -44.77 895 -40.57 0.0026
2019-05-15 2019-03-31 13F MASIMO COM 574795100 10,888 -11,599 -51.58 1,506 -37.61 0.0043
2019-02-13 2018-12-31 13F MASIMO COM 574795100 22,487 -1,890 -7.75 2,414 -20.46 0.0081
2018-11-13 2018-09-30 13F MASIMO COM 574795100 24,377 -866 -3.43 3,035 23.17 0.0086
2018-08-10 2018-06-30 13F MASIMO COM 574795100 25,243 2,418 10.59 2,464 22.77 0.0076
2018-06-28 2018-03-31 13F/A-1 MASIMO COM 574795100 22,825 -170 -0.74 2,007 2.82 0.0065
2018-05-14 2018-03-31 13F MASIMO COM 574795100 5,950 -17,045 523
2018-02-12 2017-12-31 13F MASIMO COM 574795100 22,995 5,347 30.30 1,952 27.83 0.0062
2017-11-13 2017-09-30 13F MASIMO COM 574795100 17,648 150 0.86 1,527 -4.32 0.0051
2017-08-14 2017-06-30 13F MASIMO COM 574795100 17,498 400 2.34 1,596 0.13 0.0049
2017-05-15 2017-03-31 13F MASIMO COM 574795100 17,098 -111 -0.65 1,594 37.41 0.0054
2017-02-13 2016-12-31 13F MASIMO COM 574795100 17,209 608 3.66 1,160 17.41 0.0041
2016-11-14 2016-09-30 13F MASIMO COM 574795100 16,601 -2,777 -14.33 988 -2.95 0.0034
2016-08-09 2016-06-30 13F MASIMO COM 574795100 19,378 -30 -0.15 1,018 25.37 0.0036
2016-05-13 2016-03-31 13F MASIMO COM 574795100 19,408 -1,478 -7.08 812 -6.34 0.0028
2016-02-08 2015-12-31 13F MASIMO COM 574795100 20,886 -99 -0.47 867 7.17 0.0029
2015-11-13 2015-09-30 13F MASIMO COM 574795100 20,985 394 1.91 809 1.38 0.0029
2015-08-11 2015-06-30 13F MASIMO COM 574795100 20,591 -1,169 -5.37 798 11.14 0.0026
2015-05-14 2015-03-31 13F MASIMO COM 574795100 21,760 -185 -0.84 718 24.22 0.0023
2015-02-13 2014-12-31 13F/A-1 MASIMO COM 574795100 21,945 342 1.58 578 25.65 0.0018
2015-02-09 2014-12-31 13F MASIMO COM 574795100 21,603 460
2014-11-10 2014-09-30 13F MASIMO COM 574795100 21,603 0 0.00 460 -9.80 0.0015
2014-08-08 2014-06-30 13F MASIMO COM 574795100 21,603 -3,167 -12.79 510 -24.56 0.0016
2014-05-13 2014-03-31 13F MASIMO COM 574795100 24,770 3,167 14.66 676 7.13 0.0022
2014-02-11 2013-12-31 13F MASIMO COM 574795100 21,603 -306 -1.40 631 8.05 0.0020
2013-11-08 2013-09-30 13F MASIMO COM 574795100 21,909 1,275 6.18 584 33.64 0.0021
2013-08-13 2013-06-30 13F MASIMO COM 574795100 20,634 20,634 437 0.0018
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.