Masimo
MASI
MASI was delisted on the 9th of June, 2026.
378 hedge funds and large institutions have $9.68B invested in Masimo in 2025 Q2 according to their latest regulatory filings, with 45 funds opening new positions, 126 increasing their positions, 137 reducing their positions, and 58 closing their positions.
160% more call options, than puts
Call options by funds: $10.1M | Put options by funds: $3.87M
7% more capital invested
Capital invested by funds: $9.04B → $9.68B (+$639M)
5.69% more ownership
Funds ownership: 100.39% → 106.08% (+5.7%)
0% more funds holding in top 10
Funds holding in top 10: 4 → 4 (0)
8% less repeat investments, than reductions
Existing positions increased: 126 | Existing positions reduced: 137
4% less funds holding
Funds holding: 394 → 378 (-16)
22% less first-time investments, than exits
New positions opened: 45 | Existing positions closed: 58
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
T. Rowe Price Investment Management
Baltimore,
Maryland
|
+$132M |
| 2 |
Viking Global Investors
Stamford,
Connecticut
|
+$123M |
| 3 |
BlackRock
New York
|
+$102M |
| 4 |
Westfield Capital Management
Boston,
Massachusetts
|
+$81.4M |
| 5 |
Massachusetts Financial Services
Boston,
Massachusetts
|
+$80.3M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Artisan Partners
Milwaukee,
Wisconsin
|
-$49.8M |
| 2 |
Point72 Asset Management
Stamford,
Connecticut
|
-$46.5M |
| 3 |
Capital Research Global Investors
Los Angeles,
California
|
-$32M |
| 4 |
Dimensional Fund Advisors
Austin,
Texas
|
-$28.8M |
| 5 |
Millennium Management
New York
|
-$20.9M |
MASI Hedge Fund Activity: Q2 2025 in Review
378 of the 7,596 institutional investors tracked by Wall St. Rank reported a position in Masimo (MASI) for Q2 2025, worth a combined $9.68B — up 7.1% from $9.04B a quarter earlier.
Sellers outnumbered buyers: 58 funds closed out of MASI and 45 opened new positions — a net loss of 13 holders — while 137 trimmed existing stakes and 126 added.
The largest buyer was T. Rowe Price Investment Management, adding an estimated $132M. The largest seller was Artisan Partners, exiting entirely with an estimated $49.8M sold.
- 378 institutional investors held Masimo (MASI) as of Q2 2025, down from 394 in Q1 2025.
- Funds reported $9.68B of Masimo stock for Q2 2025, up 7.1% quarter-over-quarter.
- 45 funds opened new Masimo positions in Q2 2025 and 58 closed out, a net change of -13 holders.
- The largest Masimo buyer in Q2 2025 was T. Rowe Price Investment Management, an estimated $132M added.
- The largest Masimo seller in Q2 2025 was Artisan Partners, an estimated $49.8M sold.
Based on aggregated 13F filings for Q2 2025.