Masimo
MASI
MASI was delisted on the 9th of June, 2026.
394 hedge funds and large institutions have $9.04B invested in Masimo in 2025 Q1 according to their latest regulatory filings, with 78 funds opening new positions, 136 increasing their positions, 118 reducing their positions, and 46 closing their positions.
70% more first-time investments, than exits
New positions opened: 78 | Existing positions closed: 46
29% more call options, than puts
Call options by funds: $7.35M | Put options by funds: $5.71M
15% more repeat investments, than reductions
Existing positions increased: 136 | Existing positions reduced: 118
8% more funds holding
Funds holding: 365 → 394 (+29)
6% more capital invested
Capital invested by funds: $8.5B → $9.04B (+$532M)
4.34% more ownership
Funds ownership: 96.05% → 100.39% (+4.3%)
0% more funds holding in top 10
Funds holding in top 10: 4 → 4 (0)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
BlackRock
New York
|
+$204M |
| 2 |
DCP
Durable Capital Partners
Bethesda,
Maryland
|
+$195M |
| 3 |
Holocene Advisors
New York
|
+$86.3M |
| 4 |
Artisan Partners
Milwaukee,
Wisconsin
|
+$51.9M |
| 5 |
Massachusetts Financial Services
Boston,
Massachusetts
|
+$40.4M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Capital Research Global Investors
Los Angeles,
California
|
-$69.2M |
| 2 |
Citadel Advisors
Miami,
Florida
|
-$67.9M |
| 3 |
FCM
Farallon Capital Management
San Francisco,
California
|
-$65.6M |
| 4 |
Millennium Management
New York
|
-$47.4M |
| 5 |
Assenagon Asset Management
Senningerberg,
Luxembourg
|
-$36.7M |
MASI Hedge Fund Activity: Q1 2025 in Review
394 of the 7,459 institutional investors tracked by Wall St. Rank reported a position in Masimo (MASI) for Q1 2025, worth a combined $9.04B — up 6.3% from $8.5B a quarter earlier.
Buyers outnumbered sellers: 78 funds opened new MASI positions and 46 closed out — a net gain of 32 holders — while 136 added to existing stakes and 118 trimmed.
The largest buyer was BlackRock, adding an estimated $204M. The largest seller was Capital Research Global Investors, cutting an estimated $69.2M.
- 394 institutional investors held Masimo (MASI) as of Q1 2025, up from 365 in Q4 2024.
- Funds reported $9.04B of Masimo stock for Q1 2025, up 6.3% quarter-over-quarter.
- 78 funds opened new Masimo positions in Q1 2025 and 46 closed out, a net change of +32 holders.
- The largest Masimo buyer in Q1 2025 was BlackRock, an estimated $204M added.
- The largest Masimo seller in Q1 2025 was Capital Research Global Investors, an estimated $69.2M sold.
Based on aggregated 13F filings for Q1 2025.