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MASI

Masimo Corp
$179.95 +0.00 (+0.00%) At close · Jun 12
Market Cap
$9.42B
Shares
52,365,808

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 452
Total Value: $10,095,292,770
Total Shares: 56,756,581
Showing 1–100 of 466 holdings by value · page 1 of 5

Institutional Ownership Trend

25 quarters

Superinvestors Holding MASI

All superinvestors →
Joel Greenblatt $60,736,913 George Soros $17,936,055 Mario Gabelli $16,364,040 Ray Dalio $337,775

Holder Concentration

Across 451 13F filers · Δ vs Dec 31, 2025
Top Holder
8.7%
Jun 2023 → Mar 2026 · range 8.7% – 18.7%
−7.2 pts
Top 5
33.4%
Jun 2023 → Mar 2026 · range 33.4% – 55.3%
−17.7 pts
Top 10
49.5%
Jun 2023 → Mar 2026 · range 49.5% – 69.0%
−16.2 pts
HHI
327
Jun 2023 → Mar 2026 · range 327 – 783
Broadly held−353

Quarterly Activity

vs Dec 31, 2025
New
135
Increased
141
Decreased
108
Sold Out
76
Unchanged
68
Holder count: +59
Institutional value: +26.5%
Shares held: -7.5%

Top Buyers

vs Dec 31, 2025
Institution Added Now Holds Open
Mega BARCLAYS PLC +2,685,627 2,743,985
Mega MILLENNIUM MANAGEMENT LLC +1,089,488 1,277,453
Large SG Americas Securities, LLC +506,395 522,824
Mega JPMORGAN CHASE & CO +454,847 572,645
Mid Magnetar Financial LLC +421,626 427,081

Top Sellers

vs Dec 31, 2025
Institution Sold Now Holds Open
Mega FMR LLC −6,413,341 1,450,823
Mega BlackRock, Inc. −4,211,041 4,644,578
— Joe Kiani −2,247,590 3,657,039
Large WESTFIELD CAPITAL MANAGEMENT CO LP −1,180,820 341,229
Mid Liontrust Investment Partners LLP −607,658 20,138

Top New Positions

vs Dec 31, 2025
Institution Acquired Value (USD) Open
Large Pentwater Capital Management LP 3,176,000 $564,915,120
Mid HBK INVESTMENTS L P 2,576,109 $458,212,507
Mega VANGUARD CAPITAL MANAGEMENT LLC 2,050,045 $364,641,504
Large Balyasny Asset Management L.P. 856,086 $152,272,016
Mega FIL Ltd 482,000 $85,733,340

Top Sold-Out Positions

vs Dec 31, 2025
Institution Previously Held Last Value (USD) Open
Mega VANGUARD GROUP INC 4,348,786 $565,603,105
Mega T. Rowe Price Investment Management, Inc. 2,330,158 $303,060,349
Small NAYA CAPITAL MANAGEMENT UK LTD 1,560,697 $202,984,251
Large Alyeska Investment Group, L.P. 1,259,307 $163,785,468
Large RTW INVESTMENTS, LP 683,294 $88,869,217
Filter: New 135 Increased 141 Reduced 108 Sold out 76 Unchanged 68
Showing 100 of 466
All Common Calls Puts
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Holder Value (USD) % of 13F Shares Open
Mega BlackRock, Inc. $826,131,080 8.18% 4,644,578
Small Politan Capital Management LP $816,360,689 8.09% 4,589,648
— Joe Kiani $650,477,526 6.44% 3,657,039
Large Pentwater Capital Management LP $564,915,120 5.60% 3,176,000
Mega BARCLAYS PLC $488,072,611 4.83% 2,743,985
Mid HBK INVESTMENTS L P $458,212,507 4.54% 2,576,109
Mega MASSACHUSETTS FINANCIAL SERVICES CO /MA/ $416,712,054 4.13% 2,342,790
Mega VANGUARD CAPITAL MANAGEMENT LLC $364,641,504 3.61% 2,050,045
Mega FMR LLC $258,057,884 2.56% 1,450,823
Mega STATE STREET CORP $255,727,967 2.53% 1,437,724
Mega MILLENNIUM MANAGEMENT LLC $175,887,283 1.74% 988,853
Mega GOLDMAN SACHS GROUP INC $175,058,230 1.73% 984,192
Mega GEODE CAPITAL MANAGEMENT, LLC $170,174,631 1.69% 956,736
Mega AQR CAPITAL MANAGEMENT LLC $147,981,789 1.47% 831,966
Large Balyasny Asset Management L.P. $137,135,279 1.36% 770,986
Mega MORGAN STANLEY $133,832,405 1.33% 752,417
Mega JPMORGAN CHASE & CO $101,856,363 1.01% 572,645
Mega CITIGROUP INC $94,873,723 0.94% 533,388
Large SG Americas Securities, LLC Broker-Dealer $92,994,704 0.92% 522,824
Mega FIL Ltd $85,733,340 0.85% 482,000
Mid First Trust Capital Management L.P. $85,271,410 0.84% 479,403
Mega HSBC HOLDINGS PLC $84,209,705 0.83% 473,434
Mega UBS Group AG $83,288,871 0.83% 468,257
Mega ALLIANCEBERNSTEIN L.P. $80,993,815 0.80% 455,354
Mid Magnetar Financial LLC $75,964,897 0.75% 427,081
Mid AQR Arbitrage LLC $74,163,963 0.73% 416,956
Mega NEUBERGER BERMAN GROUP LLC $71,736,571 0.71% 403,309
Mega NORTHERN TRUST CORP Bank $69,447,026 0.69% 390,437
Large Squarepoint Ops LLC $69,255,285 0.69% 389,359
Mega CHARLES SCHWAB INVESTMENT MANAGEMENT INC $68,817,547 0.68% 386,898
Large Walleye Trading LLC $64,495,662 0.64% 362,600
Mega Capital Research Global Investors $63,865,646 0.63% 359,058
Large Gotham Asset Management, LLC $60,736,913 0.60% 341,468
Large WESTFIELD CAPITAL MANAGEMENT CO LP $60,694,402 0.60% 341,229
Large Hudson Bay Capital Management LP $58,817,873 0.58% 330,679
Large Corient Private Wealth LLC $57,202,992 0.57% 321,600
Mid Fort Baker Capital Management LP $55,623,506 0.55% 312,720
Mid NEXPOINT ASSET MANAGEMENT, L.P. $55,162,823 0.55% 310,130
Large CAPITOLIS LIQUID GLOBAL MARKETS LLC $54,979,972 0.54% 309,102
Mega Bank of New York Mellon Corp Bank $54,499,362 0.54% 306,400
Large Qube Research & Technologies Ltd $51,845,725 0.51% 291,481
Mega VANGUARD FIDUCIARY TRUST CO Bank $51,558,643 0.51% 289,867
Mega MILLENNIUM MANAGEMENT LLC $51,333,282 0.51% 288,600
Mega CITADEL ADVISORS LLC $50,046,570 0.50% 281,366
Mid WHITEBOX ADVISORS LLC $48,025,077 0.48% 270,001
Large HRT FINANCIAL LP $47,106,557 0.47% 264,837
Small NUANCE INVESTMENTS, LLC $43,525,500 0.43% 244,704
Mega Amundi $43,247,844 0.43% 243,143
Small Slotnik Capital, LLC $42,742,161 0.42% 240,300
Large RENAISSANCE TECHNOLOGIES LLC $42,599,865 0.42% 239,500
Large Caption Management, LLC $41,425,923 0.41% 232,900
Mid Polar Asset Management Partners Inc. $41,270,464 0.41% 232,026
Mega BANK OF AMERICA CORP /DE/ Bank $41,266,372 0.41% 232,003
Mid MUFG Securities EMEA plc Broker-Dealer $40,091,898 0.40% 225,400
Small Beryl Capital Management LLC $38,616,110 0.38% 217,103
Mega CANADA PENSION PLAN INVESTMENT BOARD Pension $37,263,765 0.37% 209,500
Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP $36,925,812 0.37% 207,600
Large TUDOR INVESTMENT CORP ET AL $36,196,545 0.36% 203,500
Large Erste Asset Management GmbH $35,574,000 0.35% 200,000
Small WATER ISLAND CAPITAL LLC $34,541,820 0.34% 194,197
Mid ALPINE ASSOCIATES MANAGEMENT INC. $33,617,430 0.33% 189,000
Mega AMERICAN CENTURY COMPANIES INC $33,452,544 0.33% 188,073
Mega ARROWSTREET CAPITAL, LIMITED PARTNERSHIP $30,698,227 0.30% 172,588
Mid READYSTATE ASSET MANAGEMENT LP $30,436,225 0.30% 171,115
Mega RAYMOND JAMES FINANCIAL INC $30,331,636 0.30% 170,527
Large Man Group plc $29,568,219 0.29% 166,235
Mega DIMENSIONAL FUND ADVISORS LP $29,242,182 0.29% 164,402
Mid GLAZER CAPITAL, LLC $28,078,202 0.28% 157,858
Large Woodline Partners LP $27,255,731 0.27% 153,234
Large BANK OF NOVA SCOTIA Bank $27,140,116 0.27% 152,584
Large TUDOR INVESTMENT CORP ET AL $25,592,647 0.25% 143,884
Mid Capula Management Ltd $25,399,836 0.25% 142,800
Mid Champlain Investment Partners, LLC $25,130,185 0.25% 141,284
Mid Westchester Capital Management, LLC $24,622,187 0.24% 138,428
Large Grantham, Mayo, Van Otterloo & Co. LLC $24,477,935 0.24% 137,617
Mid TIG Advisors, LLC $24,047,490 0.24% 135,197
Mega UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC $23,779,258 0.24% 133,689
Mega RHUMBLINE ADVISERS $23,055,331 0.23% 129,619
Large GABELLI FUNDS LLC $22,426,205 0.22% 126,082
Large GW&K Investment Management, LLC $21,839,056 0.22% 122,781
Mid Sagefield Capital LP $21,742,827 0.22% 122,240
Large Schonfeld Strategic Advisors LLC $20,863,617 0.21% 117,297
Mid WINTON GROUP Ltd $20,060,712 0.20% 112,783
Mid Weiss Asset Management LP $20,028,162 0.20% 112,600
Mega Nuveen, LLC $19,839,974 0.20% 111,542
Large NOMURA HOLDINGS INC $19,457,199 0.19% 109,390
Mega PRINCIPAL FINANCIAL GROUP INC $18,270,450 0.18% 102,718
Mid SOROS FUND MANAGEMENT LLC $17,936,055 0.18% 100,838
Mid Kryger Capital LLC $17,891,765 0.18% 100,589
Mega SCHRODER INVESTMENT MANAGEMENT GROUP $17,107,358 0.17% 96,179
Mid GAMCO INVESTORS, INC. ET AL $16,364,040 0.16% 92,000
Large MARSHALL WACE, LLP $16,125,160 0.16% 90,657
Small CIBRA Capital Ltd $16,075,179 0.16% 90,376
Mega Swiss National Bank Bank $16,061,661 0.16% 90,300
Mega DEUTSCHE BANK AG\ Bank $15,899,263 0.16% 89,387
Small GABELLI & Co INVESTMENT ADVISERS, INC. $15,768,175 0.16% 88,650
Large Balyasny Asset Management L.P. $15,136,737 0.15% 85,100
Mega California Public Employees Retirement System Pension $13,766,604 0.14% 77,397
Large VOLORIDGE INVESTMENT MANAGEMENT, LLC $12,450,900 0.12% 70,000
Mega Invesco Ltd. $12,298,641 0.12% 69,144
Key facts CIK 937556 CUSIP 574795100 13F (30d) 26 filings 5 filers Visit website Investor relations

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