MASIMO CORP MASI
COM · Common Stock · CUSIP 574795100 · ISIN US5747951003
420
institutional holders
45.8m
shares reported held*
$6.5bnreported value*
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($22.8m this quarter). Holder counts are more reliable. Implied quarter-end price ≈ $141.20. Options: 10 managers hold calls ($11.8m notional), 6 hold puts ($5.0m).
Biggest calls
| PURA VIDA INVESTMENTS, LLC | — | $4.2m30.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | — | $3.5m25.0k shares |
| JANE STREET GROUP, LLC | — | $1.7m12.1k shares |
| CITADEL ADVISORS LLC | — | $1.2m8.5k shares |
| Walleye Trading LLC | — | $367.0k2.6k shares |
| MILLENNIUM MANAGEMENT LLC | — | $282.0k2.0k shares |
| TUDOR INVESTMENT CORP ET AL | — | $225.0k1.6k shares |
| PEAK6 Investments LLC | — | $184.0k1.3k shares |
| SIMPLEX TRADING, LLC | — | $84.0k600 shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | — | $00 shares |
Biggest puts
| PEAK6 Investments LLC | — | $2.5m17.8k shares |
| MILLENNIUM MANAGEMENT LLC | — | $988.0k7.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | — | $960.0k6.8k shares |
| CITADEL ADVISORS LLC | — | $536.0k3.8k shares |
| SIMPLEX TRADING, LLC | — | $28.0k200 shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | — | $00 shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| BlackRock, Inc. 13G · institution filed 2025-02-07 | 7.9% |
| KIANI JOE E 13G · exempt (held before listing) -3.8 pts · filed 2026-05-14 | 6.5% |
| BARCLAYS PLC 13G · institution new · filed 2026-05-14 | 5.5% |
Fell to 5% or below in the last year: Pentwater Capital Management LP (0.0%, 2026-08-14), Politan Capital Management LP (0.0%, 2026-06-11), BlackRock Portfolio Management LLC (0.2%, 2026-04-30; now reported by BlackRock, Inc.), VANGUARD GROUP INC (0.0%, 2026-03-27), FMR LLC (4.5%, 2026-03-06)
Holders, Q3 2022
| Manager | Shares | Change |
|---|---|---|
| BlackRock Inc. 0.03% of their portfolio | 5.4m $764.4m | — |
| Politan Capital Management LP 39.51% of their portfolio | 4.6m $656.2m | — |
| VANGUARD GROUP INC 0.02% of their portfolio | 4.6m $653.3m | — |
| FMR LLC 0.06% of their portfolio | 3.9m $544.5m | — |
| STATE STREET CORP 0.01% of their portfolio | 1.7m $233.9m | — |
| RTW INVESTMENTS, LP 4.69% of their portfolio | 1.4m $203.3m | — |
| Liontrust Investment Partners LLP 2.58% of their portfolio | 1.1m $161.2m | — |
| Champlain Investment Partners, LLC 0.90% of their portfolio | 934.8k $132.0m | — |
| Fundsmith LLP 0.51% of their portfolio | 765.2k $108.0m | — |
| GOLDMAN SACHS GROUP INC 0.03% of their portfolio | 728.6k $102.9m | — |
| MORGAN STANLEY 0.01% of their portfolio | 695.8k $98.2m | — |
| GEODE CAPITAL MANAGEMENT, LLC 0.01% of their portfolio | 671.5k $94.7m | — |
| CITIGROUP INC 0.12% of their portfolio | 623.9k $88.1m | — |
| FARALLON CAPITAL MANAGEMENT, L.L.C. 0.50% of their portfolio | 577.0k $81.4m | — |
| MARTIN CURRIE LTD 3.44% of their portfolio | 572.3k $80.8m | — |
| MILLENNIUM MANAGEMENT LLC 0.10% of their portfolio | 548.6k $77.4m | — |
| Bank of New York Mellon Corp 0.02% of their portfolio | 542.4k $76.6m | — |
| NEUBERGER BERMAN GROUP LLC 0.07% of their portfolio | 502.2k $71.4m | — |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.26% of their portfolio | 469.6k $66.3m | — |
| NORTHERN TRUST CORP 0.01% of their portfolio | 467.8k $66.0m | — |
| BANK OF NOVA SCOTIA 0.20% of their portfolio | 453.1k $64.0m | — |
| SCHRODER INVESTMENT MANAGEMENT GROUP 0.09% of their portfolio | 398.5k $56.3m | — |
| D. E. Shaw & Co., Inc. 0.10% of their portfolio | 394.7k $55.7m | — |
| TWO SIGMA ADVISERS, LP 0.16% of their portfolio | 393.9k $55.6m | — |
| Sumitomo Mitsui Trust Group, Inc. 0.04% of their portfolio | 382.7k $54.0m | — |
| JPMORGAN CHASE & CO 0.01% of their portfolio | 348.7k $49.2m | — |
| Legal & General Group Plc 0.02% of their portfolio | 343.5k $48.5m | — |
| Ensemble Capital Management, LLC 5.45% of their portfolio | 342.9k $48.4m | — |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.02% of their portfolio | 333.6k $47.1m | — |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.03% of their portfolio | 326.2k $46.1m | — |
| CANADA PENSION PLAN INVESTMENT BOARD 0.08% of their portfolio | 318.6k $45.0m | — |
| GENEVA CAPITAL MANAGEMENT LLC 0.98% of their portfolio | 302.0k $42.6m | — |
| Assenagon Asset Management S.A. 0.18% of their portfolio | 291.9k $41.2m | — |
| RAYMOND JAMES & ASSOCIATES 0.04% of their portfolio | 283.0k $40.0m | — |
| J.P. Morgan Private Wealth Advisors LLC 0.10% of their portfolio | 278.5k $39.3m | — |
| HSBC HOLDINGS PLC 0.07% of their portfolio | 263.7k $38.0m | — |
| Obermeyer Wealth Partners 3.01% of their portfolio | 263.5k $37.2m | — |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.03% of their portfolio | 257.2k $36.3m | — |
| Swiss National Bank 0.02% of their portfolio | 228.5k $32.3m | — |
| DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio | 225.3k $31.8m | — |
| TORONTO DOMINION BANK 0.06% of their portfolio | 223.4k $31.5m | — |
| Handelsbanken Fonder AB 0.21% of their portfolio | 219.4k $31.0m | — |
| NATIONAL BANK OF CANADA /FI/ 0.17% of their portfolio | 203.4k $28.7m | — |
| Point72 Asset Management, L.P. 0.12% of their portfolio | 203.1k $28.7m | — |
| NORGES BANK 0.01% of their portfolio | 196.5k $27.7m | — |
| PRINCIPAL FINANCIAL GROUP INC 0.02% of their portfolio | 192.2k $27.1m | — |
| CITADEL ADVISORS LLC 0.03% of their portfolio | 188.7k $26.6m | — |
| HAWK RIDGE CAPITAL MANAGEMENT LP 1.59% of their portfolio | 179.3k $25.3m | — |
| BNP PARIBAS FINANCIAL MARKETS 0.06% of their portfolio | 167.9k $23.7m | — |
| Retirement Systems of Alabama 0.10% of their portfolio | 152.5k $21.5m | — |
| ING GROEP NV 0.35% of their portfolio | 150.0k $21.2m | — |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND 0.10% of their portfolio | 145.5k $20.5m | — |
| RHUMBLINE ADVISERS 0.03% of their portfolio | 140.8k $19.9m | — |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 139.9k $19.7m | — |
| Rockefeller Capital Management L.P. 0.10% of their portfolio | 138.2k $19.5m | — |
| Invesco Ltd. 0.01% of their portfolio | 130.9k $18.5m | — |
| JANE STREET GROUP, LLC 0.03% of their portfolio | 128.7k $18.2m | — |
| BANK OF MONTREAL /CAN/ 0.01% of their portfolio | 127.7k $18.4m | — |
| AMERIPRISE FINANCIAL INC 0.01% of their portfolio | 121.8k $17.2m | — |
| Montanaro Asset Management Ltd 2.52% of their portfolio | 116.5k $16.4m | — |
| California Public Employees Retirement System 0.01% of their portfolio | 113.3k $16.0m | — |
| ACADIAN ASSET MANAGEMENT LLC 0.09% of their portfolio | 110.6k $15.6m | — |
| Nuveen Asset Management, LLC 0.01% of their portfolio | 108.2k $15.3m | — |
| Amundi 0.01% of their portfolio | 105.6k $15.4m | — |
| Allspring Global Investments Holdings, LLC 0.03% of their portfolio | 102.6k $14.5m | — |
| Alyeska Investment Group, L.P. 0.17% of their portfolio | 100.0k $14.1m | — |
| BRITISH COLUMBIA INVESTMENT MANAGEMENT Corp 0.16% of their portfolio | 98.7k $13.9m | — |
| BAILLIE GIFFORD & CO 0.01% of their portfolio | 93.6k $13.2m | — |
| UBS Group AG 0.01% of their portfolio | 89.4k $12.6m | — |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.02% of their portfolio | 86.0k $12.1m | — |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.02% of their portfolio | 85.9k $12.1m | — |
| GAMCO INVESTORS, INC. ET AL 0.14% of their portfolio | 85.0k $12.0m | — |
| Bridgewater Associates, LP 0.06% of their portfolio | 78.6k $11.1m | — |
| SCOUT INVESTMENTS, INC. 0.22% of their portfolio | 76.7k $10.8m | — |
| AMERICAN INTERNATIONAL GROUP, INC. 0.08% of their portfolio | 76.4k $10.8m | — |
| ALLIANCEBERNSTEIN L.P. 0.01% of their portfolio | 75.6k $10.7m | — |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 71.4k $10.1m | — |
| CREDIT SUISSE AG/ 0.01% of their portfolio | 69.2k $9.8m | — |
| 2Xideas AG 1.01% of their portfolio | 68.1k $9.6m | — |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.02% of their portfolio | 65.8k $9.3m | — |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC 0.16% of their portfolio | 65.4k $9.2m | — |
| Mirae Asset Global Investments Co., Ltd. 0.02% of their portfolio | 65.3k $9.2m | — |
| Cubist Systematic Strategies, LLC 0.07% of their portfolio | 64.6k $9.1m | — |
| NEW YORK STATE COMMON RETIREMENT FUND 0.01% of their portfolio | 63.8k $9.0m | — |
| DekaBank Deutsche Girozentrale 0.03% of their portfolio | 62.9k $8.9m | — |
| TWO SIGMA INVESTMENTS, LP 0.03% of their portfolio | 62.9k $8.9m | — |
| Janney Montgomery Scott LLC 0.04% of their portfolio | 61.2k $8.6m | — |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.02% of their portfolio | 55.9k $7.9m | — |
| LOGAN CAPITAL MANAGEMENT INC 0.47% of their portfolio | 55.2k $7.8m | — |
| Bell Asset Management Ltd 1.48% of their portfolio | 51.8k $7.3m | — |
| EATON VANCE MANAGEMENT 0.01% of their portfolio | 51.7k $7.3m | — |
| SEI INVESTMENTS CO 0.02% of their portfolio | 51.7k $7.3m | — |
| Handelsinvest Investeringsforvaltning 1.13% of their portfolio | 51.1k $7.2m | — |
| Wilmington Savings Fund Society, FSB 0.35% of their portfolio | 50.5k $7.1m | — |
| CANADA LIFE ASSURANCE Co 0.02% of their portfolio | 48.9k $6.9m | — |
| AVIVA PLC 0.04% of their portfolio | 48.6k $6.9m | — |
| FIRST TRUST ADVISORS LP 0.01% of their portfolio | 48.4k $6.8m | — |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 47.8k $6.7m | — |
| Asset Management One Co., Ltd. 0.03% of their portfolio | 47.2k $6.7m | — |
| State of Tennessee, Department of Treasury 0.03% of their portfolio | 46.2k $6.5m | — |