Masimo Corporation
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionUBS Group AG
Latest Disclosed Ownership468,257 shares
Latest Disclosed Value $ 83,288,873
UBS Group AG ownership in MASI / Masimo Corporation

On May 5, 2026 - UBS Group AG filed a 13F-HR form disclosing ownership of 468,257 shares of Masimo Corporation (MX:MASI) valued at $83,288,873 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 29, 2026 disclosing 599,274 shares of Masimo Corporation. This represents a change in shares of -21.86% during the quarter.

UBS Group AG has a history of taking positions in derivatives of the underlying security (MASI) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:MASI / Masimo Corporation Historical Put/Call Ratio
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)
2026-05-05 2026-03-31 13F MASIMO COM 574795100 468,257 -131,017 -21.86 83,289 6.86 0.0023
2026-01-29 2025-12-31 13F MASIMO COM 574795100 599,274 429,474 252.93 77,942 211.10 0.0126
2025-11-13 2025-09-30 13F MASIMO COM 574795100 169,800 27,636 19.44 25,054 4.76 0.0039
2025-08-14 2025-06-30 13F MASIMO COM 574795100 142,164 -28,013 -16.46 23,915 -15.65 0.0041
2025-05-13 2025-03-31 13F MASIMO COM 574795100 170,177 10,149 6.34 28,351 7.18 0.0052
2025-02-14 2024-12-31 13F MASIMO COM 574795100 160,028 105,346 192.65 26,453 262.85 0.0049
2024-11-14 2024-09-30 13F MASIMO COM 574795100 54,682 10,821 24.67 7,291 31.99 0.0016
2024-08-14 2024-06-30 13F MASIMO COM 574795100 43,861 109 0.25 5,524 -14.03 0.0014
2024-05-13 2024-03-31 13F MASIMO COM 574795100 43,752 11,628 36.20 6,425 70.62 0.0016
2024-02-09 2023-12-31 13F MASIMO COM 574795100 32,124 -15,944 -33.17 3,765 -10.65 0.0011
2023-11-09 2023-09-30 13F MASIMO COM 574795100 48,068 -33,518 -41.08 4,215 -68.61 0.0015
2023-08-11 2023-06-30 13F MASIMO COM 574795100 81,586 -13,329 -14.04 13,425 -23.36 0.0045
2023-05-12 2023-03-31 13F MASIMO COM 574795100 94,915 -1,740 -1.80 17,516 22.48 0.0064
2023-02-08 2022-12-31 13F MASIMO COM 574795100 96,655 7,256 8.12 14,300 13.31 0.0053
2022-11-10 2022-09-30 13F MASIMO COM 574795100 89,399 -12,385 -12.17 12,620 -5.11 0.0055
2022-08-10 2022-06-30 13F MASIMO COM 574795100 101,784 -103,318 -50.37 13,300 -55.45 0.0055
2022-05-16 2022-03-31 13F MASIMO COM 574795100 205,102 -6,827 -3.22 29,851 -51.89 0.0100
2022-02-14 2021-12-31 13F MASIMO COM 574795100 211,929 3,715 1.78 62,049 10.08 0.0178
2021-11-15 2021-09-30 13F MASIMO COM 574795100 208,214 -38,118 -15.47 56,366 -5.62 0.0177
2021-08-13 2021-06-30 13F MASIMO COM 574795100 246,332 5,732 2.38 59,723 8.08 0.0193
2021-05-12 2021-03-31 13F MASIMO COM 574795100 240,600 -5,700 -2.31 55,257 -16.41 0.0183
2021-02-11 2020-12-31 13F MASIMO COM 574795100 246,300 -5,246 -2.09 66,101 11.32 0.0223
2020-11-12 2020-09-30 13F MASIMO COM 574795100 251,546 55,633 28.40 59,379 32.94 0.0224
2020-07-31 2020-06-30 13F MASIMO COM 574795100 195,913 -41,208 -17.38 44,666 6.35 0.0189
2020-05-01 2020-03-31 13F MASIMO COM 574795100 237,121 -91,643 -27.88 41,999 -19.18 0.0198
2020-02-14 2019-12-31 13F MASIMO COM 574795100 328,764 43,630 15.30 51,964 22.48 0.0181
2019-11-14 2019-09-30 13F MASIMO COM 574795100 285,134 685 0.24 42,425 0.22 0.0163
2019-08-14 2019-06-30 13F MASIMO COM 574795100 284,449 23,513 9.01 42,332 17.32 0.0163
2019-05-14 2019-03-31 13F MASIMO COM 574795100 260,936 64,178 32.62 36,082 70.80 0.0149
2019-02-14 2018-12-31 13F MASIMO COM 574795100 196,758 169,650 625.83 21,125 525.74 0.0096
2018-11-14 2018-09-30 13F MASIMO COM 574795100 27,108 2,925 12.10 3,376 42.93 0.0013
2018-08-14 2018-06-30 13F MASIMO COM 574795100 24,183 13,438 125.06 2,362 149.95 0.0010
2018-05-15 2018-03-31 13F MASIMO COM 574795100 10,745 -20,990 -66.14 945 -64.88 0.0004
2018-02-14 2017-12-31 13F MASIMO COM 574795100 31,735 16,020 101.94 2,691 97.87 0.0011
2017-11-14 2017-09-30 13F MASIMO COM 574795100 15,715 -832 -5.03 1,360 -9.81 0.0006
2017-11-14 2017-06-30 13F/A-1 MASIMO COM 574795100 16,547 4,275 34.84 1,508 31.70 0.0008
2017-08-14 2017-06-30 13F MASIMO COM 574795100 16,547 4,275 1,508
2017-11-14 2017-03-31 13F/A-1 MASIMO COM 574795100 12,272 -3,306 -21.22 1,145 9.05 0.0006
2017-05-12 2017-03-31 13F MASIMO COM 574795100 12,272 -3,306 1,145
2017-02-14 2016-12-31 13F MASIMO COM 574795100 15,578 3,277 26.64 1,050 43.44 0.0006
2016-11-14 2016-09-30 13F MASIMO COM 574795100 12,301 914 8.03 732 22.41 0.0004
2016-08-12 2016-06-30 13F MASIMO COM 574795100 11,387 -7,790 -40.62 598 -25.44 0.0004
2016-05-12 2016-03-31 13F MASIMO COM 574795100 19,177 663 3.58 802 4.43 0.0005
2016-02-16 2015-12-31 13F MASIMO COM 574795100 18,514 998 5.70 768 13.61 0.0005
2015-11-13 2015-09-30 13F MASIMO COM 574795100 17,516 -1,371 -7.26 676 -7.65 0.0005
2015-08-14 2015-06-30 13F MASIMO COM 574795100 18,887 2,587 15.87 732 36.06 0.0005
2015-05-14 2015-03-31 13F MASIMO COM 574795100 16,300 -34,674 -68.02 538 -59.94 0.0004
2015-02-17 2014-12-31 13F MASIMO COM 574795100 50,974 50,974 1,343 0.0009
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-08-14 2025-06-30 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-13 2025-03-31 13F MASIMO COM Call 20,000 3,332 n/a n/a n/a
2024-02-09 2023-12-31 13F MASIMO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-09 2023-09-30 13F MASIMO COM Call 18,600 1,631 n/a n/a n/a
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.