MASIMO CORP MASI*
Latest 13F among current holders filed 5 days ago (Aug 28, 2026)
Institutional holders
451
+60 QoQ
13F value
$9.69B
+32.3% QoQ
Smart-money holders
30
signal tier ≥ 2
New smart buyers
21
Q1 2026
Options barometer
10.8×
$266.6M calls / $24.6M puts
Institutional value by quarter
Number of holders
Who owns MASI*?
Q1 2026 filings| Fund | Type | Shares | Value | % of fund | Change |
|---|---|---|---|---|---|
| BlackRock, Inc. | Index provider | 4.6M | $826.1M | 0.0% | -47.6% |
| Politan Capital Management LP ★2 | Fundamental diversified | 4.6M | $816.4M | — | Held |
| Pentwater Capital Management LP ★2 | Fundamental concentrated | 3.2M | $564.9M | 4.0% | New |
| BARCLAYS PLC | Bank broker | 2.7M | $488.1M | 0.2% | +4602.0% |
| HBK INVESTMENTS L P ★2 | Fundamental diversified | 2.6M | $458.2M | 6.2% | New |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ | Other | 2.3M | $416.7M | — | -12.1% |
| VANGUARD CAPITAL MANAGEMENT LLC | Diversified mechanical | 2.1M | $364.6M | — | — |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Diversified mechanical | 2.0M | $357.0M | — | — |
| FMR LLC | Long only active | 1.5M | $258.1M | 0.0% | -81.6% |
| STATE STREET CORP | Index provider | 1.4M | $255.7M | 0.0% | +1.6% |
| MILLENNIUM MANAGEMENT LLC | Multistrat pod | 988.9K | $175.9M | 0.1% | +426.1% |
| GOLDMAN SACHS GROUP INC | Bank broker | 984.2K | $175.1M | 0.0% | +54.6% |
| GEODE CAPITAL MANAGEMENT, LLC | Index provider | 956.7K | $170.2M | — | +0.3% |
| AQR CAPITAL MANAGEMENT LLC | Quant stat arb | 832.0K | $147.4M | 0.1% | -23.8% |
| Balyasny Asset Management L.P. | Multistrat pod | 771.0K | $137.1M | 0.3% | New |
| MORGAN STANLEY | Bank broker | 752.4K | $133.8M | 0.0% | -18.3% |
| Davidson Kempner Capital Management LP | Quant stat arb | 586.0K | $104.2M | 2.8% | New |
| JPMORGAN CHASE & CO | Bank broker | 572.6K | $101.5M | 0.0% | +386.1% |
| CITIGROUP INC | Bank broker | 533.4K | $94.9M | 0.1% | +340.0% |
| SG Americas Securities, LLC | Diversified mechanical | 522.8K | $93.0M | 0.1% | +3082.3% |
| FIL Ltd | Other | 482.0K | $85.7M | 0.1% | New |
| First Trust Capital Management L.P. | Quant stat arb | 479.4K | $85.3M | — | New |
| HSBC HOLDINGS PLC | Bank broker | 473.4K | $84.3M | 0.1% | New |
| UBS Group AG | Bank broker | 468.3K | $83.3M | 0.0% | -21.9% |
| Magnetar Financial LLC | Quant stat arb | 427.1K | $76.0M | — | +7729.2% |
| AQR Arbitrage LLC | Other | 417.0K | $73.9M | — | New |
| O'Connor Alternative Investments LLC ★2 | Fundamental diversified | 412.9K | $73.4M | — | — |
| NEUBERGER BERMAN GROUP LLC | Diversified mechanical | 403.3K | $71.7M | 0.1% | +7956.5% |
| NORTHERN TRUST CORP | Index provider | 390.4K | $69.4M | 0.0% | +2.6% |
| Squarepoint Ops LLC | Quant stat arb | 389.4K | $69.3M | 0.1% | -33.3% |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | Index provider | 386.9K | $68.8M | — | +6.9% |
| Capital Research Global Investors | Long only active | 359.1K | $63.9M | 0.0% | -43.7% |
| Gotham Asset Management, LLC | Diversified mechanical | 341.5K | $60.7M | 0.2% | -0.2% |
| WESTFIELD CAPITAL MANAGEMENT CO LP | Other | 341.2K | $60.7M | — | -77.6% |
| ALLIANCEBERNSTEIN L.P. | Long only active | 455.4K | $59.2M | 0.0% | +739.8% |
| Hudson Bay Capital Management LP | Multistrat pod | 330.7K | $58.8M | 0.4% | New |
| Corient Private Wealth LLC | Diversified mechanical | 321.6K | $57.2M | 0.1% | -52.8% |
| Fort Baker Capital Management LP ★2 | Fundamental concentrated | 312.7K | $55.6M | — | New |
| NEXPOINT ASSET MANAGEMENT, L.P. ★2 | Fundamental diversified | 310.1K | $55.2M | — | New |
| CAPITOLIS LIQUID GLOBAL MARKETS LLC | Other | 309.1K | $55.0M | 0.3% | — |
| Bank of New York Mellon Corp | Diversified mechanical | 306.4K | $54.5M | 0.0% | -0.7% |
| Qube Research & Technologies Ltd | Quant stat arb | 291.5K | $51.8M | — | -0.7% |
| VANGUARD FIDUCIARY TRUST CO | Diversified mechanical | 289.9K | $51.6M | — | — |
| CITADEL ADVISORS LLC | Multistrat pod | 281.4K | $50.0M | 0.0% | +553.5% |
| WHITEBOX ADVISORS LLC | Other | 270.0K | $48.0M | — | New |
| HRT FINANCIAL LP | Diversified mechanical | 264.8K | $47.1M | 0.1% | +185.5% |
| NUANCE INVESTMENTS, LLC ★3 | Fundamental concentrated | 244.7K | $43.5M | — | New |
| Amundi | Diversified mechanical | 243.1K | $43.2M | 0.0% | +454.4% |
| Slotnik Capital, LLC ★2 | Fundamental concentrated | 240.3K | $42.7M | — | New |
| RENAISSANCE TECHNOLOGIES LLC | Quant stat arb | 239.5K | $42.6M | — | +299.8% |
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