Institutional Ownership
Masimo Corp
CUSIP 574795100COMMASIQ1 2026
13D / 13G Filings
51
Schedule 13D/13G on record
Beneficial Filers
8
Distinct reporting persons
Largest Stake
16.3%
Max % of class reported
Institutional Holders
433
13F filers (latest quarter)
Beneficial Owners — Schedule 13D / 13G
51 filings · latest Mar 6, 2026
| # | Filed | Reporting Person | Form | % of Class | Shares | Filing |
|---|---|---|---|---|---|---|
| 1 | Mar 6, 2026 | Fmr LLC | 13G/A | 4.5% | 2.35M | SEC |
| 2 | Feb 17, 2026 | Politan Capital Management LP | 13D/A | 6.2% | — | SEC |
| 3 | Feb 13, 2026 | Joe Kiani | 13G/A | 10.3% | 5.90M | SEC |
| 4 | Jan 21, 2026 | Blackrock Portfolio Management LLC | 13G/A | 8.2% | 4.39M | SEC |
| 5 | Nov 12, 2025 | Joe Kiani | 13G/A | 11.1% | 6.38M | SEC |
| 6 | Aug 12, 2025 | Joe Kiani | 13G/A | 11.4% | 6.58M | SEC |
| 7 | Apr 22, 2025 | Joe Kiani | 13G/A | 13.2% | 7.62M | SEC |
| 8 | Mar 4, 2025 | Blackrock Portfolio Management LLC | 13G | 10.3% | 5.54M | SEC |
| 9 | Feb 12, 2025 | Fmr LLC | 13G/A | 15.0% | 8.03M | SEC |
| 10 | Feb 7, 2025 | Blackrock, Inc. | 13G/A | 7.9% | 4.23M | SEC |
41 more beneficial-ownership filings on Premium
See the full Schedule 13D/13G history for Masimo Corp.
Unlock full historyTop Institutional Holders (13F)
Largest reported positions · latest quarter
| # | Fund | Shares | Value |
|---|---|---|---|
| 1 | Blackrock, Inc. | 4.64M | $826.13M |
| 2 | Politan Capital Management LP | 4.59M | $816.36M |
| 3 | Pentwater Capital Management LP | 3.18M | $564.92M |
| 4 | Barclays PLC | 2.74M | $488.07M |
| 5 | Hbk Investments L P | 2.58M | $458.21M |
| 6 | Massachusetts Financial Services Co /Ma/ | 2.34M | $416.69M |
| 7 | Fmr LLC | 1.45M | $258.06M |
| 8 | State Street Corp | 1.44M | $255.73M |
| 9 | Millennium Management LLC | 988.9K | $175.89M |
| 10 | Goldman Sachs Group Inc | 984.2K | $175.06M |