마시모 코퍼레이션
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionRenaissance Technologies Llc
ManagerJames Simons
Latest Disclosed Ownership239,500 shares
Latest Disclosed Value $ 42,599,865
Renaissance Technologies Llc reports 299.83% increase in ownership of MASI / Masimo Corporation

On May 14, 2026 - Renaissance Technologies Llc filed a 13F-HR form disclosing ownership of 239,500 shares of Masimo Corporation (MX:MASI) valued at $42,599,865 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 59,900 shares of Masimo Corporation. This represents a change in shares of 299.83% 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 239,500 179,600 299.83 42,600 446.84 0.0666
2026-02-12 2025-12-31 13F MASIMO COM 574795100 59,900 59,900 7,791 0.0121
2025-11-13 2025-09-30 13F MASIMO COM 574795100 0 -25,377 -100.00 0 -100.00
2025-08-13 2025-06-30 13F MASIMO COM 574795100 25,377 10,377 69.18 4,269 70.79 0.0057
2025-05-14 2025-03-31 13F MASIMO COM 574795100 15,000 15,000 2,499 0.0038
2023-11-14 2023-09-30 13F MASIMO COM 574795100 0 -41,230 -100.00 0 -100.00
2023-08-11 2023-06-30 13F MASIMO COM 574795100 41,230 -40,070 -49.29 7 -60.00 0.0098
2023-05-12 2023-03-31 13F MASIMO COM 574795100 81,300 -98,400 -54.76 15 -42.31 0.0199
2023-02-13 2022-12-31 13F MASIMO COM 574795100 179,700 131,900 275.94 27 -99.61 0.0364
2022-11-14 2022-09-30 13F MASIMO COM 574795100 47,800 47,800 6,747 0.0095
2022-05-13 2022-03-31 13F MASIMO COM 574795100 0 -6,200 -100.00 0 -100.00
2022-02-11 2021-12-31 13F MASIMO COM 574795100 6,200 6,200 1,815 0.0023
2021-08-13 2021-06-30 13F MASIMO COM 574795100 0 -1,100 -100.00 0 -100.00
2021-05-13 2021-03-31 13F MASIMO COM 574795100 1,100 1,100 253 0.0003
2021-02-10 2020-12-31 13F MASIMO COM 574795100 0 -82,600 -100.00 0 -100.00
2020-11-13 2020-09-30 13F MASIMO COM 574795100 82,600 67,700 454.36 19,499 474.01 0.0195
2020-08-13 2020-06-30 13F MASIMO COM 574795100 14,900 -4,100 -21.58 3,397 0.95 0.0029
2020-05-14 2020-03-31 13F MASIMO COM 574795100 19,000 -7,021 -26.98 3,365 -18.19 0.0033
2020-02-13 2019-12-31 13F MASIMO COM 574795100 26,021 -78,679 -75.15 4,113 -73.60 0.0032
2019-11-13 2019-09-30 13F MASIMO COM 574795100 104,700 -169,300 -61.79 15,578 -61.80 0.0132
2019-08-12 2019-06-30 13F MASIMO COM 574795100 274,000 -71,000 -20.58 40,777 -14.53 0.0359
2019-05-14 2019-03-31 13F MASIMO COM 574795100 345,000 -193,300 -35.91 47,707 -17.46 0.0434
2019-02-12 2018-12-31 13F MASIMO COM 574795100 538,300 235,500 77.77 57,797 53.26 0.0633
2018-11-13 2018-09-30 13F MASIMO COM 574795100 302,800 -249,826 -45.21 37,711 -30.12 0.0388
2018-08-13 2018-06-30 13F/A-1 MASIMO COM 574795100 552,626 41,126 8.04 53,964 19.96 0.0588
2018-08-13 2018-06-30 13F MASIMO COM 574795100 511,500 44,986
2018-05-14 2018-03-31 13F MASIMO COM 574795100 511,500 -40,600 -7.35 44,986 -3.91 0.0492
2018-02-13 2017-12-31 13F MASIMO COM 574795100 552,100 -131,300 -19.21 46,818 -20.86 0.0516
2017-11-13 2017-09-30 13F MASIMO COM 574795100 683,400 62,900 10.14 59,155 4.56 0.0696
2017-08-11 2017-06-30 13F MASIMO COM 574795100 620,500 191,400 44.60 56,577 41.38 0.0722
2017-05-12 2017-03-31 13F MASIMO COM 574795100 429,100 255,700 147.46 40,018 242.41 0.0559
2017-02-13 2016-12-31 13F MASIMO COM 574795100 173,400 94,900 120.89 11,687 150.26 0.0185
2016-11-14 2016-09-30 13F MASIMO COM 574795100 78,500 -65,300 -45.41 4,670 -38.16 0.0083
2016-08-12 2016-06-30 13F MASIMO COM 574795100 143,800 -88,900 -38.20 7,552 -22.43 0.0144
2016-05-13 2016-03-31 13F MASIMO COM 574795100 232,700 10,300 4.63 9,736 5.46 0.0185
2016-02-11 2015-12-31 13F MASIMO COM 574795100 222,400 109,200 96.47 9,232 111.50 0.0201
2015-11-12 2015-09-30 13F MASIMO COM 574795100 113,200 -42,400 -27.25 4,365 -27.59 0.0104
2015-08-14 2015-06-30 13F MASIMO COM 574795100 155,600 12,900 9.04 6,028 28.09 0.0137
2015-05-13 2015-03-31 13F MASIMO COM 574795100 142,700 42,600 42.56 4,706 78.46 0.0100
2015-02-13 2014-12-31 13F MASIMO COM 574795100 100,100 -236,100 -70.23 2,637 -63.14 0.0064
2014-11-12 2014-09-30 13F MASIMO COM 574795100 336,200 73,965 28.21 7,154 15.59 0.0196
2014-08-13 2014-06-30 13F MASIMO COM 574795100 262,235 262,235 -22.00 6,189 -13.49 0.0144
2014-02-14 2013-12-31 13F MASIMO COM 574795100 0 -60,600 -100.00 0 -100.00
2013-11-13 2013-09-30 13F MASIMO COM 574795100 60,600 -396,600 -86.75 1,614 -83.35 0.0039
2013-08-12 2013-06-30 13F MASIMO COM 574795100 457,200 457,200 9,693 0.0254
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.