Vault-13

MASIMO CORP MASI

COM · Common Stock · CUSIP 574795100 · ISIN US5747951003

358 institutional holders -22 vs Q2 2025
56,294,69856.3m shares reported held*
$8.3bnreported value*
44 new 120 added 121 reduced 63 sold out net sold ≈ $187.6m (-1.3m shares)

* 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 ($3.4m this quarter). Holder counts are more reliable. Implied quarter-end price ≈ $147.50. Options: 6 managers hold calls ($5.5m notional), 5 hold puts ($5.5m).

Trends to Q3 2025

Institutional holders

Managers reporting a position, each quarter

0200400600Q3 22: 420Q4 22: 405Q1 23: 429Q2 23: 417Q3 23: 358Q4 23: 343Q1 24: 341Q2 24: 353Q3 24: 363Q4 24: 367Q1 25: 394Q2 25: 380Q3 25: 358358Q3 22Q2 23Q1 24Q4 24Q3 25
Numbers
QuarterHolders
Q3 2022420
Q4 2022405
Q1 2023429
Q2 2023417
Q3 2023358
Q4 2023343
Q1 2024341
Q2 2024353
Q3 2024363
Q4 2024367
Q1 2025394
Q2 2025380
Q3 2025358

Buyers vs sellers

Managers adding to or starting a position, vs cutting or selling out

Bought or addedCut or sold out
4000400Q4 23: 157 bought or addedQ4 23: 193 cut or sold outQ1 24: 140 bought or addedQ1 24: 177 cut or sold outQ1 24Q2 24: 170 bought or addedQ2 24: 151 cut or sold outQ3 24: 169 bought or addedQ3 24: 170 cut or sold outQ3 24Q4 24: 162 bought or addedQ4 24: 169 cut or sold outQ1 25: 206 bought or addedQ1 25: 161 cut or sold outQ1 25Q2 25: 166 bought or addedQ2 25: 195 cut or sold outQ3 25: 164 bought or addedQ3 25: 184 cut or sold outQ3 25
Numbers
QuarterBought or addedCut or sold out
Q4 2023157193
Q1 2024140177
Q2 2024170151
Q3 2024169170
Q4 2024162169
Q1 2025206161
Q2 2025166195
Q3 2025164184

Calls vs puts

Options held, notional value, last 4 quarters. P/C = puts ÷ calls

CallsPuts
$0$10m$20m$30mQ4 24 calls: $21.3mQ4 24 puts: $12.6mQ4 24P/C 0.59Q1 25 calls: $7.3mQ1 25 puts: $5.7mQ1 25P/C 0.78Q2 25 calls: $10.1mQ2 25 puts: $3.9mQ2 25P/C 0.38Q3 25 calls: $5.5mQ3 25 puts: $5.5mQ3 25P/C 1.00
Numbers
QuarterCallsPutsP/C
Q4 2024$21.3m$12.6m0.59
Q1 2025$7.3m$5.7m0.78
Q2 2025$10.1m$3.9m0.38
Q3 2025$5.5m$5.5m1.00

Biggest buyers

Squarepoint Ops LLC Added +546,905+546.9k
VIKING GLOBAL INVESTORS LP Added +306,007+306.0k
GOLDMAN SACHS GROUP INC Added +272,877+272.9k
Alyeska Investment Group, L.P. Added +246,595+246.6k
WESTFIELD CAPITAL MANAGEMENT CO LP Added +238,047+238.0k
BANK OF AMERICA CORP /DE/ Added +214,885+214.9k
VANGUARD GROUP INC Added +171,876+171.9k
ADAGE CAPITAL PARTNERS GP, L.L.C. New +150,000+150.0k
MASSACHUSETTS FINANCIAL SERVICES CO /MA/ Added +149,567+149.6k
MARSHALL WACE, LLP Added +126,914+126.9k

Biggest sellers

Holocene Advisors, LP Sold out -1,243,607-1.2m
ALLIANCEBERNSTEIN L.P. Reduced -790,506-790.5k
Durable Capital Partners LP Reduced -543,279-543.3k
T. Rowe Price Investment Management, Inc. Reduced -373,381-373.4k
DIMENSIONAL FUND ADVISORS LP Reduced -263,558-263.6k
Woodline Partners LP Sold out -182,709-182.7k
HAWK RIDGE CAPITAL MANAGEMENT LP Sold out -148,685-148.7k
BlackRock, Inc. Reduced -146,235-146.2k
Politan Capital Management LP Reduced -126,888-126.9k
SCHRODER INVESTMENT MANAGEMENT GROUP Reduced -111,851-111.9k

Biggest calls

SUSQUEHANNA INTERNATIONAL GROUP, LLP Reduced $2.9m19.8k shares
CITADEL ADVISORS LLC Added $1.6m10.8k shares
JANE STREET GROUP, LLC Added $619.7k4.2k shares
WOLVERINE TRADING, LLC New $200.1k1.4k shares
SIMPLEX TRADING, LLC Reduced $162.0k1.1k shares
GROUP ONE TRADING LLC New $14.8k100 shares

Biggest puts

SUSQUEHANNA INTERNATIONAL GROUP, LLP Added $4.5m30.8k shares
CITADEL ADVISORS LLC Added $383.6k2.6k shares
WOLVERINE TRADING, LLC New $228.7k1.6k shares
JANE STREET GROUP, LLC New $221.3k1.5k shares
SIMPLEX TRADING, LLC Added $147.0k1.0k 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.

HolderStakeChangeShares Last filed
BlackRock, Inc. 13G · institution filed 2025-02-07 7.9% 4.2m 2025-02-07
KIANI JOE E 13G · exempt (held before listing) -3.8 pts · filed 2026-05-14 6.5% -3.8 pts 3.7m 2026-05-14
BARCLAYS PLC 13G · institution new · filed 2026-05-14 5.5% new 2.9m 2026-05-14

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 2025

#ManagerLocationShares Value% of their portfolioChangeShares change
1 BlackRock, Inc. 0.03% of their portfolio New York, NY 10,361,09110.4m $1.5bn $1.5bn 0.03% Reduced -146.2k -146,235
2 FMR LLC 0.06% of their portfolio BOSTON, MA 8,213,7218.2m $1.2bn $1.2bn 0.06% Added +32.3k +32,349
3 VANGUARD GROUP INC 0.01% of their portfolio Valley Forge, PA 4,810,0114.8m $709.7m $709.7m 0.01% Added +171.9k +171,876
4 Politan Capital Management LP 61.54% of their portfolio NEW YORK, NY 4,589,6484.6m $677.2m $677.2m 61.54% Reduced -126.9k -126,888
5 MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.12% of their portfolio Boston, MA 2,619,9602.6m $386.6m $386.6m 0.12% Added +149.6k +149,567
6 T. Rowe Price Investment Management, Inc. 0.19% of their portfolio BALTIMORE, MD 2,126,7632.1m $313.8m $313.8m 0.19% Reduced -373.4k -373,381
7 Capital Research Global Investors 0.05% of their portfolio Los Angeles, CA 1,854,1281.9m $273.6m $273.6m 0.05% Reduced -1.5k -1,542
8 STATE STREET CORP 0.01% of their portfolio BOSTON, MA 1,484,4711.5m $219.0m $219.0m 0.01% Reduced -1.9k -1,923
9 WESTFIELD CAPITAL MANAGEMENT CO LP 0.88% of their portfolio BOSTON, MA 1,419,2501.4m $209.4m $209.4m 0.88% Added +238.0k +238,047
10 Alyeska Investment Group, L.P. 0.62% of their portfolio CHICAGO, IL 1,381,0851.4m $203.8m $203.8m 0.62% Added +246.6k +246,595
11 VIKING GLOBAL INVESTORS LP 0.41% of their portfolio STAMFORD, CT 1,073,4331.1m $158.4m $158.4m 0.41% Added +306.0k +306,007
12 GEODE CAPITAL MANAGEMENT, LLC 0.01% of their portfolio BOSTON, MA 942,439942.4k $139.1m $139.1m 0.01% Added +46.0k +46,021
13 GOLDMAN SACHS GROUP INC 0.02% of their portfolio NEW YORK, NY 744,402744.4k $109.8m $109.8m 0.02% Added +272.9k +272,877
14 MORGAN STANLEY 0.01% of their portfolio NEW YORK, NY 690,601690.6k $101.9m $101.9m 0.01% Reduced -76.8k -76,774
15 RTW INVESTMENTS, LP 1.24% of their portfolio NEW YORK, NY 683,294683.3k $100.8m $100.8m 1.24% Unchanged
16 Liontrust Investment Partners LLP 1.47% of their portfolio LONDON, X0 681,895681.9k $100.6m $100.6m 1.47% Reduced -26.4k -26,405
17 Squarepoint Ops LLC 0.19% of their portfolio NEW YORK, NY 620,932620.9k $91.6m $91.6m 0.19% Added +546.9k +546,905
18 Durable Capital Partners LP 0.68% of their portfolio Bethesda, MD 620,619620.6k $91.6m $91.6m 0.68% Reduced -543.3k -543,279
19 PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio BALTIMORE, MD 514,946514.9k $76.0m $76.0m 0.01% Added +109.5k +109,486
20 AMERIPRISE FINANCIAL INC 0.02% of their portfolio MINNEAPOLIS, MN 460,951461.0k $68.0m $68.0m 0.02% Added +66.5k +66,464
21 BANK OF AMERICA CORP /DE/ 0.00% of their portfolio CHARLOTTE, NC 405,061405.1k $59.8m $59.8m 0.00% Added +214.9k +214,885
22 Sumitomo Mitsui Trust Group, Inc. 0.03% of their portfolio CHIYODA-KU, TOKYO, M0 397,248397.2k $58.6m $58.6m 0.03% Reduced -73.8k -73,793
23 NORTHERN TRUST CORP 0.01% of their portfolio CHICAGO, IL 392,142392.1k $57.9m $57.9m 0.01% Added +3.6k +3,600
24 BAMCO INC /NY/ 0.15% of their portfolio NEW YORK, NY 388,747388.7k $57.4m $57.4m 0.15% Added +4.2k +4,158
25 CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.01% of their portfolio SAN FRANCISCO, CA 364,457364.5k $53.8m $53.8m 0.01% Reduced -6.3k -6,277
26 SCHRODER INVESTMENT MANAGEMENT GROUP 0.04% of their portfolio London, X0 336,650336.6k $48.1m $48.1m 0.04% Reduced -111.9k -111,851
27 Corient Private Wealth LP 0.08% of their portfolio MIAMI, FL 336,215336.2k $49.6m $49.6m 0.08% Added +5.8k +5,801
28 Invesco Ltd. 0.01% of their portfolio ATLANTA, GA 321,363321.4k $47.4m $47.4m 0.01% Added +84.1k +84,060
29 Bank of New York Mellon Corp 0.01% of their portfolio NEW YORK, NY 312,618312.6k $46.1m $46.1m 0.01% Reduced -5.0k -4,975
30 DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio AUSTIN, TX 259,668259.7k $38.3m $38.3m 0.01% Reduced -263.6k -263,558
31 Grantham, Mayo, Van Otterloo & Co. LLC 0.10% of their portfolio Boston, MA 242,822242.8k $35.8m $35.8m 0.10% Added +2.3k +2,259
32 COMERICA BANK 0.13% of their portfolio DALLAS, TX 233,427233.4k $34.4m $34.4m 0.13% Added +43.6k +43,605
33 Nuveen, LLC 0.01% of their portfolio CHARLOTTE, NC 225,712225.7k $33.3m $33.3m 0.01% Added +76.1k +76,054
34 JPMORGAN CHASE & CO 0.00% of their portfolio NEW YORK, NY 215,882215.9k $31.9m $31.9m 0.00% Added +77.8k +77,792
35 RAYMOND JAMES FINANCIAL INC 0.01% of their portfolio ST. PETERSBURG, FL 196,021196.0k $28.9m $28.9m 0.01% Reduced -4.2k -4,208
36 UBS Group AG 0.00% of their portfolio ZURICH, V8 169,800169.8k $25.1m $25.1m 0.00% Added +27.6k +27,636
37 AMERICAN CENTURY COMPANIES INC 0.01% of their portfolio KANSAS CITY, MO 168,341168.3k $24.8m $24.8m 0.01% Added +16.1k +16,113
38 BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.06% of their portfolio Paris, I0 164,926164.9k $24.3m $24.3m 0.06% Added +99.1k +99,105
39 Erste Asset Management GmbH 0.22% of their portfolio VIENNA, C4 160,000160.0k $22.9m $22.9m 0.22% Added +68.0k +68,000
40 ADAGE CAPITAL PARTNERS GP, L.L.C. 0.04% of their portfolio Boston, MA 150,000150.0k $22.1m $22.1m 0.04% New
41 Rockefeller Capital Management L.P. 0.04% of their portfolio NEW YORK, NY 147,428147.4k $21.8m $21.8m 0.04% Added +31.8k +31,802
42 MARSHALL WACE, LLP 0.02% of their portfolio LONDON, X0 134,122134.1k $19.8m $19.8m 0.02% Added +126.9k +126,914
43 Tidal Investments LLC 0.08% of their portfolio Milwaukee, WI 132,557132.6k $19.6m $19.6m 0.08% Added +26.4k +26,359
44 Gotham Asset Management, LLC 0.08% of their portfolio NEW YORK, NY 129,026129.0k $19.0m $19.0m 0.08% Reduced -36.3k -36,330
45 ROYAL BANK OF CANADA 0.00% of their portfolio TORONTO, A6 127,117127.1k $18.8m $18.8m 0.00% Reduced -92.3k -92,263
46 RHUMBLINE ADVISERS 0.02% of their portfolio BOSTON, MA 126,608126.6k $18.7m $18.7m 0.02% Reduced -888 -888
47 GW&K Investment Management, LLC 0.16% of their portfolio BOSTON, MA 124,047124.0k $18.3m $18.3m 0.16% Added +123.9k +123,912
48 CITIGROUP INC 0.01% of their portfolio NEW YORK, NY 116,672116.7k $17.2m $17.2m 0.01% Added +66.7k +66,710
49 CRAMER ROSENTHAL MCGLYNN LLC 1.09% of their portfolio STAMFORD, CT 114,605114.6k $16.9m $16.9m 1.09% Added +19.7k +19,666
50 UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio NEW YORK, NY 109,110109.1k $16.1m $16.1m 0.00% Reduced -100.5k -100,453
51 DF DENT & CO INC 0.21% of their portfolio BALTIMORE, MD 108,653108.7k $16.0m $16.0m 0.21% New
52 TD Asset Management Inc 0.01% of their portfolio Toronto, A6 107,858107.9k $15.9m $15.9m 0.01% Reduced -59.3k -59,318
53 Legal & General Group Plc 0.00% of their portfolio London, X0 102,677102.7k $15.1m $15.1m 0.00% Reduced -1.7k -1,687
54 PRINCIPAL FINANCIAL GROUP INC 0.01% of their portfolio DES MOINES, IA 102,184102.2k $15.1m $15.1m 0.01% Reduced -283 -283
55 Alpha Wave Global, LP 1.45% of their portfolio Miami, FL 97,10297.1k $14.3m $14.3m 1.45% Reduced -5.0k -4,966
56 Bellevue Group AG 0.30% of their portfolio ZURICH, V8 96,96897.0k $14.3m $14.3m 0.30% Added +7.3k +7,295
57 Walleye Capital LLC 0.11% of their portfolio NEW YORK, NY 89,36389.4k $13.2m $13.2m 0.11% Added +46.1k +46,131
58 Swiss National Bank 0.01% of their portfolio ZURICH, V8 89,30089.3k $13.2m $13.2m 0.01% Added +1.6k +1,600
59 CITADEL ADVISORS LLC 0.01% of their portfolio MIAMI, FL 87,75087.8k $12.9m $12.9m 0.01% Added +63.5k +63,473
60 Amundi 0.00% of their portfolio Paris, I0 84,89484.9k $12.6m $12.6m 0.00% Added +43.3k +43,311
61 JUPITER ASSET MANAGEMENT LTD 0.11% of their portfolio London, X0 84,65784.7k $12.5m $12.5m 0.11% New
62 GAMCO INVESTORS, INC. ET AL 0.12% of their portfolio GREENWICH, CT 83,80083.8k $12.4m $12.4m 0.12% Reduced -700 -700
63 California Public Employees Retirement System 0.01% of their portfolio Sacramento, CA 78,46078.5k $11.6m $11.6m 0.01% Added +5.7k +5,653
64 BARCLAYS PLC 0.00% of their portfolio LONDON, X0 77,80477.8k $11.5m $11.5m 0.00% Added +21.7k +21,690
65 BLI - Banque de Luxembourg Investments 0.29% of their portfolio LUXEMBOURG CITY, N4 68,50068.5k $9.8m $9.8m 0.29% Reduced -18.2k -18,200
66 Swedbank AB 0.01% of their portfolio STOCKHOLM, V7 67,50067.5k $10.0m $10.0m 0.01% Reduced -6.3k -6,300
67 FIRST TRUST ADVISORS LP 0.01% of their portfolio Wheaton, IL 61,93461.9k $9.1m $9.1m 0.01% Reduced -37.7k -37,678
68 Retirement Systems of Alabama 0.03% of their portfolio MONTGOMERY, AL 55,83155.8k $8.2m $8.2m 0.03% Added +828 +828
69 ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio NASHVILLE, TN 53,56153.6k $7.9m $7.9m 0.00% Reduced -790.5k -790,506
70 BRIDGER MANAGEMENT, LLC 3.80% of their portfolio NEW YORK, NY 47,84147.8k $7.1m $7.1m 3.80% Added +14.2k +14,200
71 CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio WEST SACRAMENTO, CA 43,35543.4k $6.4m $6.4m 0.01% Added +2 +2
72 NS Partners Ltd 0.24% of their portfolio LONDON, X0 42,39442.4k $6.3m $6.3m 0.24% Reduced -172 -172
73 STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.01% of their portfolio TALLAHASSEE, FL 41,07941.1k $6.1m $6.1m 0.01% Reduced -2.2k -2,240
74 NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio ALBANY, NY 40,04840.0k $5.9m $5.9m 0.01% Unchanged
75 Quantinno Capital Management LP 0.02% of their portfolio NEW YORK, NY 39,58939.6k $5.8m $5.8m 0.02% Reduced -80.8k -80,794
76 STRS OHIO 0.02% of their portfolio COLUMBUS, OH 36,91336.9k $5.4m $5.4m 0.02% Reduced -19.1k -19,070
77 Baird Financial Group, Inc. 0.01% of their portfolio MILWAUKEE, WI 35,83435.8k $5.3m $5.3m 0.01% Reduced -4.9k -4,886
78 CAPITAL FUND MANAGEMENT S.A. 0.05% of their portfolio PARIS, I0 34,42434.4k $5.1m $5.1m 0.05% New
79 MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio Toronto, A6 34,19334.2k $5.0m $5.0m 0.00% Reduced -24.5k -24,521
80 VICTORY CAPITAL MANAGEMENT INC 0.00% of their portfolio San Antonio, TX 33,04533.0k $4.9m $4.9m 0.00% Added +3.7k +3,677
81 GABELLI FUNDS LLC 0.03% of their portfolio Rye, NY 32,70032.7k $4.8m $4.8m 0.03% Unchanged
82 NORDEA INVESTMENT MANAGEMENT AB 0.00% of their portfolio STOCKHOLM, V7 32,49932.5k $4.7m $4.7m 0.00% Added +631 +631
83 TUDOR INVESTMENT CORP ET AL 0.03% of their portfolio STAMFORD, CT 31,64131.6k $4.7m $4.7m 0.03% New
84 AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio Greenwich, CT 31,03431.0k $4.4m $4.4m 0.00% Reduced -19.2k -19,222
85 Engineers Gate Manager LP 0.05% of their portfolio NEW YORK, NY 30,77330.8k $4.5m $4.5m 0.05% Added +23.9k +23,900
86 INTECH INVESTMENT MANAGEMENT LLC 0.04% of their portfolio WEST PALM BEACH, FL 29,69029.7k $4.4m $4.4m 0.04% Reduced -2.1k -2,060
87 Onex Canada Asset Management Inc. 0.52% of their portfolio TORONTO, A6 27,92327.9k $4.1m $4.1m 0.52% Added +19.7k +19,699
88 STOREBRAND ASSET MANAGEMENT AS 0.01% of their portfolio LYSAKER, Q8 27,73227.7k $4.1m $4.1m 0.01% Added +10.0k +10,000
89 Ensign Peak Advisors, Inc 0.01% of their portfolio SALT LAKE CITY, UT 27,36127.4k $4.0m $4.0m 0.01% Added +11.4k +11,385
90 WILSON ASSET MANAGEMENT (INTERNATIONAL) PTY LTD 0.99% of their portfolio SYDNEY, C3 27,23427.2k $4.0m $4.0m 0.99% Unchanged
91 CANADA LIFE ASSURANCE Co 0.01% of their portfolio WINNIPEG, A2 27,12027.1k $3.9m $3.9m 0.01% Added +1.0k +1,000
92 Westmount Partners, LLC 0.95% of their portfolio LOS ANGELES, CA 25,86625.9k $3.7m $3.7m 0.95% Unchanged
93 MetLife Investment Management, LLC 0.02% of their portfolio Whippany, NJ 25,84925.8k $3.8m $3.8m 0.02% Reduced -436 -436
94 LOGAN CAPITAL MANAGEMENT INC 0.16% of their portfolio Newtown Square, PA 25,10525.1k $3.7m $3.7m 0.16% Reduced -6.2k -6,247
95 Advisors Asset Management, Inc. 0.06% of their portfolio Monument, CO 24,18824.2k $3.6m $3.6m 0.06% Reduced -195 -195
96 NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio ALBANY, NY 24,16024.2k $3.6m $3.6m 0.00% Unchanged
97 South Dakota Investment Council 0.07% of their portfolio SIOUX FALLS, SD 23,06823.1k $3.4m $3.4m 0.07% Reduced -1.7k -1,700
98 AMALGAMATED BANK 0.02% of their portfolio NEW YORK, NY 22,60122.6k $3.3m $3.3m 0.02% Added +858 +858
99 STATE OF WISCONSIN INVESTMENT BOARD 0.01% of their portfolio MADISON, WI 21,73821.7k $3.2m $3.2m 0.01% Added +94 +94
100 SEI INVESTMENTS CO 0.00% of their portfolio OAKS, PA 21,65521.7k $3.2m $3.2m 0.00% Reduced -8.9k -8,851