Masimo Corporation
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership20,000 shares
Latest Disclosed Value $ 3,557,000
Janus Henderson Group Plc ownership in MASI / Masimo Corporation

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 20,000 shares of Masimo Corporation (MX:MASI) valued at $3,557,000 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 20,000 shares of Masimo Corporation. This represents a change in shares of 0.00% 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)
2026-05-18 2026-03-31 13F/A-1 MASIMO COM 574795100 20,000 0 0.00 3,557 36.76 0.0006
2026-05-15 2026-03-31 13F MASIMO COM 574795100 20,000 0 3,557 0.0007
2026-02-17 2025-12-31 13F MASIMO COM 574795100 20,000 0 0.00 2,601 -11.89 0.0012
2025-11-14 2025-09-30 13F MASIMO COM 574795100 20,000 0 0.00 2,952 -12.25 0.0013
2025-08-14 2025-06-30 13F MASIMO COM 574795100 20,000 0 0.00 3,364 2.87 0.0016
2025-05-15 2025-03-31 13F MASIMO COM 574795100 20,000 -1,000 -4.76 3,270 -5.79 0.0018
2025-02-14 2024-12-31 13F MASIMO COM 574795100 21,000 -800 -3.67 3,472 19.40 0.0018
2024-11-14 2024-09-30 13F MASIMO COM 574795100 21,800 0 0.00 2,907 5.86 0.0015
2024-08-14 2024-06-30 13F MASIMO COM 574795100 21,800 -230 -1.04 2,747 -15.04 0.0015
2024-05-15 2024-03-31 13F MASIMO COM 574795100 22,030 -1,224 -5.26 3,232 18.61 0.0018
2024-02-14 2023-12-31 13F MASIMO COM 574795100 23,254 -1,639 -6.58 2,726 24.89 0.0016
2023-11-14 2023-09-30 13F MASIMO COM 574795100 24,893 20,188 429.08 2,182 181.91 0.0014
2023-08-14 2023-06-30 13F MASIMO COM 574795100 4,705 -610 -11.48 774 -21.10 0.0005
2023-05-15 2023-03-31 13F MASIMO COM 574795100 5,315 -13 -0.24 981 24.49 0.0006
2023-02-14 2022-12-31 13F MASIMO COM 574795100 5,328 1 0.02 788 4.79 0.0006
2022-11-14 2022-09-30 13F MASIMO COM 574795100 5,327 -1,102 -17.14 752 -10.48 0.0006
2022-08-15 2022-06-30 13F MASIMO COM 574795100 6,429 -1,249 -16.27 840 -24.87 0.0006
2022-05-16 2022-03-31 13F MASIMO COM 574795100 7,678 -2,444 -24.15 1,118 -62.26 0.0005
2022-02-14 2021-12-31 13F MASIMO COM 574795100 10,122 -1,028 -9.22 2,962 -1.86 0.0012
2021-11-16 2021-09-30 13F MASIMO COM 574795100 11,150 -20,840 -65.15 3,018 -61.08 0.0013
2021-08-16 2021-06-30 13F MASIMO COM 574795100 31,990 -43,184 -57.45 7,755 -55.09 0.0033
2021-05-17 2021-03-31 13F MASIMO COM 574795100 75,174 50,004 198.67 17,266 155.60 0.0079
2021-02-16 2020-12-31 13F MASIMO COM 574795100 25,170 -22,100 -46.75 6,755 -39.47 0.0031
2020-11-16 2020-09-30 13F MASIMO COM 574795100 47,270 12,068 34.28 11,159 39.05 0.0058
2020-08-14 2020-06-30 13F MASIMO COM 574795100 35,202 15,783 81.28 8,025 133.35 0.0045
2020-05-14 2020-03-31 13F MASIMO COM 574795100 19,419 -629,466 -97.01 3,439 -96.65 0.0024
2020-02-18 2019-12-31 13F MASIMO COM 574795100 648,885 -56,928 -8.07 102,563 -2.34 0.0525
2019-11-14 2019-09-30 13F MASIMO COM 574795100 705,813 13,860 2.00 105,018 1.98 0.0569
2019-07-31 2019-06-30 13F MASIMO COM 574795100 691,953 101,354 17.16 102,976 26.09 0.0561
2019-04-30 2019-03-31 13F MASIMO COM 574795100 590,599 61,762 11.68 81,668 43.83 0.0453
2019-02-06 2018-12-31 13F MASIMO COM 574795100 528,837 72,343 15.85 56,781 -0.12 0.0362
2018-11-09 2018-09-30 13F MASIMO COM 574795100 456,494 -2,593 -0.56 56,852 26.82 0.0304
2018-08-10 2018-06-30 13F MASIMO COM 574795100 459,087 22,518 5.16 44,830 16.76 0.0256
2018-05-14 2018-03-31 13F MASIMO COM 574795100 436,569 -6,596 -1.49 38,396 2.17 0.0226
2018-03-12 2017-12-31 13F/A-1 MASIMO COM 574795100 443,165 83,711 23.29 37,580 20.78 0.0231
2018-02-09 2017-12-31 13F MASIMO COM 574795100 443,165 83,711 37,580
2017-11-14 2017-09-30 13F MASIMO COM 574795100 359,454 -108,599 -23.20 31,114 -27.09 0.0199
2017-08-17 2017-06-30 13F/A-1 MASIMO COM 574795100 468,053 -22,558 -4.60 42,677 -6.73 0.0291
2017-08-14 2017-06-30 13F MASIMO COM 574795100 468,053 -22,558 42,677
2017-05-03 2017-03-31 13F MASIMO COM 574795100 490,611 -112,523 -18.66 45,754 12.55 0.3212
2017-01-30 2016-12-31 13F MASIMO COM 574795100 603,134 -117,121 -16.26 40,651 -5.13 0.2998
2016-10-24 2016-09-30 13F MASIMO COM 574795100 720,255 -4,811 -0.66 42,848 12.53 0.3158
2016-07-29 2016-06-30 13F MASIMO COM 574795100 725,066 265,011 57.60 38,077 97.81 0.3166
2016-05-12 2016-03-31 13F MASIMO COM 574795100 460,055 -13,314 -2.81 19,249 -2.04 0.1561
2016-02-03 2015-12-31 13F MASIMO COM 574795100 473,369 7,514 1.61 19,650 9.39 0.1577
2015-11-16 2015-09-30 13F MASIMO COM 574795100 465,855 86,885 22.93 17,963 22.36 0.1582
2015-08-17 2015-06-30 13F MASIMO COM 574795100 378,970 -5,102 -1.33 14,681 -12.77 0.1154
2015-06-02 2015-03-31 13F/A-1 MASIMO COM 574795100 384,072 81,098 26.77 16,830 110.90 0.1298
2015-05-15 2015-03-31 13F MASIMO COM 574795100 384,072 16,830
2015-02-12 2014-12-31 13F MASIMO COM 574795100 302,974 302,974 7,980 0.0575
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.