519 institutions reported holding $9.77B of Masimo Corp (MASI) in SEC 13F filings for 2026-03-31. Largest institutional holders: BlackRock, Inc. ($826.1M), Politan Capital Management LP ($816.4M), Pentwater Capital Management LP ($564.9M), BARCLAYS PLC ($488.1M), HBK INVESTMENTS L P ($458.2M). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | BlackRock, Inc. | $826.1M | 4.6M | Trimmed |
| 2 | Politan Capital Management LP | $816.4M | 4.6M | Hold |
| 3 | Pentwater Capital Management LP | $564.9M | 3.2M | New |
| 4 | BARCLAYS PLC | $488.1M | 2.7M | Added |
| 5 | HBK INVESTMENTS L P | $458.2M | 2.6M | New |
| 6 | MASSACHUSETTS FINANCIAL SERVICES CO /MA/ | $416.7M | 2.3M | Trimmed |
| 7 | VANGUARD CAPITAL MANAGEMENT LLC | $364.6M | 2.1M | New |
| 8 | VANGUARD PORTFOLIO MANAGEMENT LLC | $357.0M | 2.0M | New |
| 9 | FMR LLC | $258.1M | 1.5M | Trimmed |
| 10 | STATE STREET CORP | $255.7M | 1.4M | Added |
| 11 | MILLENNIUM MANAGEMENT LLC | $227.2M | 1.3M | Added |
| 12 | GOLDMAN SACHS GROUP INC | $175.1M | 984,192 | Added |
| 13 | GEODE CAPITAL MANAGEMENT, LLC | $170.2M | 956,736 | Added |
| 14 | Balyasny Asset Management L.P. | $152.3M | 856,086 | New |
| 15 | AQR CAPITAL MANAGEMENT LLC | $147.4M | 831,966 | Trimmed |
| 16 | MORGAN STANLEY | $133.8M | 752,417 | Trimmed |
| 17 | JPMORGAN CHASE & CO | $101.5M | 572,645 | Added |
| 18 | CITIGROUP INC | $94.9M | 533,388 | Added |
| 19 | SG Americas Securities, LLC | $93.0M | 522,824 | Added |
| 20 | FIL Ltd | $85.7M | 482,000 | New |
| 21 | First Trust Capital Management L.P. | $85.3M | 479,403 | New |
| 22 | HSBC HOLDINGS PLC | $84.3M | 473,434 | New |
| 23 | UBS Group AG | $83.3M | 468,257 | Trimmed |
| 24 | Magnetar Financial LLC | $76.0M | 427,081 | Added |
| 25 | AQR Arbitrage LLC | $73.9M | 416,956 | New |
Source: SEC Form 13F filings · as of 2026-03-31