Masimo Corporation
MX ˙ BMV ˙ US5747951003
SecurityMX:MASI / Masimo Corporation
InstitutionNomura Holdings Inc
Latest Disclosed Ownership109,390 shares
Latest Disclosed Value $ 19,457,199
Nomura Holdings Inc ownership in MASI / Masimo Corporation

On May 15, 2026 - Nomura Holdings Inc filed a 13F-HR form disclosing ownership of 109,390 shares of Masimo Corporation (MX:MASI) valued at $19,457,199 USD as of March 31, 2026. The entity filed a previous 13F-HR on May 15, 2025 disclosing 0 shares of Masimo Corporation.

Nomura Holdings Inc 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)
2026-05-15 2026-03-31 13F MASIMO COM 574795100 109,390 109,390 19,457 0.0516
2025-05-15 2025-03-31 13F MASIMO COM 574795100 0 -5,897 -100.00 0 -100.00
2025-02-14 2024-12-31 13F MASIMO COM 574795100 5,897 -41,687 -87.61 975 -84.65 0.0013
2025-01-13 2024-09-30 13F/A-1 MASIMO COM 574795100 47,584 -1,738,723 -97.34 6,344 -97.38 0.0146
2024-11-14 2024-09-30 13F MASIMO COM 574795100 47,584 -1,738,723 6,344 0.0146
2022-08-17 2022-06-30 13F/A-1 MASIMO CMN 574795100 1,786,307 1,786,307 242,537 0.8354
2021-11-15 2021-09-30 13F MASIMO CMN 574795100 0 -5,000 -100.00 0 -100.00
2021-08-16 2021-06-30 13F MASIMO CMN 574795100 5,000 -12,310 -71.11 1,212 40,300.00 0.0031
2021-05-17 2021-03-31 13F MASIMO CMN 574795100 17,310 17,310 246.20 4 -99.75 0.0090
2021-02-16 2020-12-31 13F MASIMO CMN 574795100 0 -1,186 -100.00 0 -100.00
2020-11-12 2020-09-30 13F MASIMO CMN 574795100 1,186 -3,814 -76.28 279 -75.46 0.0006
2020-08-14 2020-06-30 13F MASIMO CMN 574795100 5,000 5,000 321.59 1,137 307.53 0.0040
2019-02-14 2018-12-31 13F MASIMO CMN 574795100 0 -2,897 -100.00 0 -100.00
2018-11-14 2018-09-30 13F MASIMO CMN 574795100 2,897 -3,192 -52.42 360 -39.50 0.0013
2018-08-17 2018-06-30 13F/A-1 MASIMO CMN 574795100 6,089 -1,212 -16.60 595 -4.03 0.0019
2018-08-14 2018-06-30 13F MASIMO CMN 574795100 6,089 -1,212 515
2018-05-14 2018-03-31 13F MASIMO CMN 574795100 7,301 0 0.00 620 0.00 0.0005
2018-02-14 2017-12-31 13F MASIMO CMN 574795100 7,301 2,426 49.76 620 46.92 0.0011
2017-11-14 2017-09-30 13F MASIMO CMN 574795100 4,875 2,668 120.89 422 108.91 0.0009
2017-08-15 2017-06-30 13F MASIMO CMN 574795100 2,207 -3,240 -59.48 202 -60.24 0.0005
2017-05-18 2017-03-31 13F/A-1 MASIMO CMN 574795100 5,447 5,447 146.81 508 151.49 0.0013
2017-05-15 2017-03-31 13F MASIMO CMN 574795100 5,447 508
2016-11-14 2016-09-30 13F MASIMO CMN 574795100 0 -5,455 -100.00 0 -100.00
2016-09-02 2016-06-30 13F/A-1 MASIMO CMN 574795100 5,455 5,455 0.00 286 0.0009
2016-08-15 2016-06-30 13F MASIMO CMN 574795100 5,455 286
2016-05-16 2016-03-31 13F MASIMO CMN 574795100 0 -14,325 -100.00 0 -100.00
2016-02-12 2015-12-31 13F MASIMO CMN 574795100 14,325 14,325 0.00 595 0.0017
2014-11-14 2014-09-30 13F MASIMO CMN 574795100 0 -27,840 -100.00 0 -100.00
2014-08-13 2014-06-30 13F MASIMO CMN 574795100 27,840 17,102 159.27 661 126.37 0.0002
2014-05-14 2014-03-31 13F MASIMO CMN 574795100 10,738 10,738 -61.43 292 -55.82 0.0001
2013-11-14 2013-09-30 13F MASIMO CMN 574795100 0 -21,472 -100.00 0 -100.00
2013-08-15 2013-06-30 13F MASIMO CMN 574795100 21,472 4,916 29.69 455 40.00 0.0037
2013-08-16 2013-03-31 13F/A-2 MASIMO CMN 574795100 16,556 16,556 325 0.0034
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
(%)
2021-11-15 2021-09-30 13F MASIMO CMN Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-08-16 2021-06-30 13F MASIMO CMN Call 82,300 19,956 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.