Masimo Corporation
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionFmr Llc
Latest Disclosed Ownership2,349,974 shares
Ownership 4.50%
Fmr Llc ownership in MASI / Masimo Corporation

2026-03-06 - Fmr Llc has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 2,349,974 shares of Masimo Corporation (MX:MASI). This represents 4.5 percent ownership of the company. In their previous filing dated 2025-02-12 , Fmr Llc had reported owning 8,031,083 shares, indicating a decrease of -70.74 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2026-03-06 2026-03-06 13G/A 8,031,083 2,349,974 -70.74 4.50 -70.00
2025-02-12 2025-02-12 13G/A 6,927,572 8,031,083 15.93 15.00 14.42
2024-02-09 2024-02-09 13G/A 5,456,343 6,927,572 26.96 13.11 26.30
2023-01-10 2023-01-10 13G 2,054,898 5,456,343 165.53 10.38 178.96
2022-02-09 2022-02-09 13G/A 3,827,970 2,054,898 -46.32 3.72 -46.48
2021-02-08 2021-02-08 13G/A 6,039,566 3,827,970 -36.62 6.95 -38.08
2020-04-10 2020-04-10 13G/A 4,706,036 6,039,566 28.34 11.23 27.90
2020-02-07 2020-02-07 13G/A 3,889,562 4,706,036 20.99 8.78 19.61
2019-02-13 2019-02-13 13G 3,889,562 7.34
2014-10-10 2014-10-10 13G/A 1,131,755 2.07
2014-03-10 2014-03-10 13G/A 5,705,773 10.06
2014-02-14 2014-02-14 13G 3,823,001 6.76
2012-02-14 2012-02-14 13G/A 2,476,500 4.13

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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 1,450,823 -6,413,341 -81.55 258,058 -74.77 0.0027
2026-02-17 2025-12-31 13F MASIMO COM 574795100 7,864,164 -349,557 -4.26 1,022,813 -15.60 0.0522
2025-11-13 2025-09-30 13F MASIMO COM 574795100 8,213,721 32,349 0.40 1,211,935 -11.94 0.0630
2025-08-14 2025-06-30 13F MASIMO COM 574795100 8,181,372 2,609 0.03 1,376,270 1.00 0.0776
2025-05-12 2025-03-31 13F MASIMO COM 574795100 8,178,763 81,309 1.00 1,362,582 1.80 0.0870
2025-02-13 2024-12-31 13F MASIMO COM 574795100 8,097,454 1,340,836 19.84 1,338,509 48.58 0.0799
2024-11-13 2024-09-30 13F MASIMO COM 574795100 6,756,618 1,970,883 41.18 900,860 49.47 0.0548
2024-08-13 2024-06-30 13F MASIMO COM 574795100 4,785,735 -2,191,546 -31.41 602,716 -41.18 0.0386
2024-05-13 2024-03-31 13F MASIMO COM 574795100 6,977,281 49,709 0.72 1,024,614 26.19 0.0688
2024-02-13 2023-12-31 13F MASIMO COM 574795100 6,927,572 1,680,009 32.02 811,981 76.48 0.0624
2023-11-13 2023-09-30 13F MASIMO COM 574795100 5,247,563 -1,909,714 -26.68 460,106 -60.93 0.0398
2023-08-11 2023-06-30 13F MASIMO COM 574795100 7,157,277 1,072,321 17.62 1,177,730 4.88 0.0987
2023-08-11 2023-03-31 13F/A-1 MASIMO COM 574795100 6,084,956 628,612 11.52 1,122,918 39.10 0.1027
2023-05-11 2023-03-31 13F MASIMO COM 574795100 6,084,956 628,612 1,122,918 0.1027
2023-02-13 2022-12-31 13F MASIMO COM 574795100 5,456,344 1,599,054 41.46 807,266 48.26 0.0802
2022-11-10 2022-09-30 13F MASIMO COM 574795100 3,857,290 1,752,351 83.25 544,495 97.96 0.0568
2022-08-12 2022-06-30 13F MASIMO COM 574795100 2,104,939 35,438 1.71 275,052 -8.68 0.0274
2022-05-13 2022-03-31 13F MASIMO COM 574795100 2,069,501 14,603 0.71 301,195 -49.94 0.0241
2022-02-14 2021-12-31 13F MASIMO COM 574795100 2,054,898 -23,092 -1.11 601,633 6.95 0.0444
2022-02-14 2021-09-30 13F/A-1 MASIMO COM 574795100 2,077,990 -3,796 -0.18 562,531 11.45 0.0446
2021-11-15 2021-09-30 13F MASIMO COM 574795100 2,077,990 -3,796 562,531 0.0446
2021-08-13 2021-06-30 13F MASIMO COM 574795100 2,081,786 -330,268 -13.69 504,730 -8.89 0.0395
2021-05-14 2021-03-31 13F MASIMO COM 574795100 2,412,054 -1,415,917 -36.99 553,953 -46.08 0.0473
2021-02-08 2020-12-31 13F MASIMO COM 574795100 3,827,971 -618,375 -13.91 1,027,350 -2.12 0.0914
2020-11-13 2020-09-30 13F MASIMO COM 574795100 4,446,346 -665,723 -13.02 1,049,604 -9.94 0.1061
2020-08-24 2020-06-30 13F/A-1 MASIMO COM 574795100 5,112,069 -927,497 -15.36 1,165,501 8.95 0.1281
2020-08-13 2020-06-30 13F MASIMO COM 574795100 5,112,069 -927,497 1,165,501 28,632.9489
2020-05-14 2020-03-31 13F MASIMO COM 574795100 6,039,566 1,333,529 28.34 1,069,728 43.81 0.1481
2020-02-07 2019-12-31 13F MASIMO COM 574795100 4,706,037 442,681 10.38 743,836 17.26 0.0821
2019-11-13 2019-09-30 13F MASIMO COM 574795100 4,263,356 70,047 1.67 634,344 1.65 0.0761
2019-08-13 2019-06-30 13F MASIMO COM 574795100 4,193,309 14,501 0.35 624,048 8.00 0.0729
2019-05-13 2019-03-31 13F MASIMO COM 574795100 4,178,808 289,246 7.44 577,845 38.37 0.0692
2019-02-13 2018-12-31 13F MASIMO COM 574795100 3,889,562 587,587 17.80 417,622 1.55 0.0572
2018-11-09 2018-09-30 13F MASIMO COM 574795100 3,301,975 1,479,981 81.23 411,229 131.13 0.0463
2018-08-10 2018-06-30 13F MASIMO COM 574795100 1,821,994 1,794,822 6,605.41 177,918 7,344.27 0.0210
2018-05-14 2018-03-31 13F MASIMO COM 574795100 27,172 1,174 4.52 2,390 8.39 0.0003
2018-02-12 2017-12-31 13F MASIMO COM 574795100 25,998 -124,002 -82.67 2,205 -84.24 0.0003
2017-05-11 2017-03-31 13F MASIMO COM 574795100 150,000 -300,000 -66.67 13,989 -53.88 0.0018
2017-02-10 2016-12-31 13F MASIMO COM 574795100 450,000 50,000 12.50 30,330 27.46 0.0041
2016-11-14 2016-09-30 13F MASIMO COM 574795100 400,000 70,000 21.21 23,796 37.31 0.0032
2016-08-11 2016-06-30 13F MASIMO COM 574795100 330,000 -57,652 -14.87 17,330 6.85 0.0024
2016-05-16 2016-03-31 13F MASIMO COM 574795100 387,652 100 0.03 16,219 0.82 0.0022
2016-02-12 2015-12-31 13F MASIMO COM 574795100 387,552 4,126 1.08 16,087 8.81 0.0022
2015-11-10 2015-09-30 13F MASIMO COM 574795100 383,426 -20,050 -4.97 14,785 -5.41 0.0021
2015-08-25 2015-06-30 13F/A-1 MASIMO COM 574795100 403,476 5,584 1.40 15,631 19.12 0.0020
2015-08-13 2015-06-30 13F MASIMO COM 574795100 403,476 15,631
2015-05-14 2015-03-31 13F MASIMO COM 574795100 397,892 11,018 2.85 13,122 28.77 0.0017
2015-02-17 2014-12-31 13F MASIMO COM 574795100 386,874 -744,881 -65.82 10,190 -57.69 0.0013
2014-11-14 2014-09-30 13F MASIMO COM 574795100 1,131,755 -3,949,700 -77.73 24,084 -79.92 0.0033
2014-08-14 2014-06-30 13F MASIMO COM 574795100 5,081,455 -1,067,838 -17.37 119,922 -28.59 0.0161
2014-05-15 2014-03-31 13F MASIMO COM 574795100 6,149,293 2,326,293 60.85 167,937 50.28 0.0233
2014-02-13 2013-12-31 13F MASIMO COM 574795100 3,823,000 2,316,300 153.73 111,747 178.41 0.0158
2013-11-14 2013-09-30 13F MASIMO COM 574795100 1,506,700 1,506,700 40,138 0.0062
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.