Masimo
MASI
MASI was delisted on the 9th of June, 2026.
358 hedge funds and large institutions have $8.29B invested in Masimo in 2025 Q3 according to their latest regulatory filings, with 47 funds opening new positions, 119 increasing their positions, 121 reducing their positions, and 64 closing their positions.
0% more funds holding in top 10
Funds holding in top 10: 4 → 4 (0)
0% less call options, than puts
Call options by funds: $5.51M | Put options by funds: $5.53M
2% less repeat investments, than reductions
Existing positions increased: 119 | Existing positions reduced: 121
2.61% less ownership
Funds ownership: 106.08% → 103.47% (-2.6%)
5% less funds holding
Funds holding: 378 → 358 (-20)
14% less capital invested
Capital invested by funds: $9.68B → $8.29B (-$1.38B)
27% less first-time investments, than exits
New positions opened: 47 | Existing positions closed: 64
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Squarepoint
New York
|
+$82.8M |
| 2 |
Viking Global Investors
Stamford,
Connecticut
|
+$46.3M |
| 3 |
Goldman Sachs
New York
|
+$41.3M |
| 4 |
Alyeska Investment Group
Chicago,
Illinois
|
+$37.3M |
| 5 |
Westfield Capital Management
Boston,
Massachusetts
|
+$36M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Holocene Advisors
New York
|
-$209M |
| 2 |
AllianceBernstein
Nashville,
Tennessee
|
-$120M |
| 3 |
DCP
Durable Capital Partners
Bethesda,
Maryland
|
-$82.2M |
| 4 |
T. Rowe Price Investment Management
Baltimore,
Maryland
|
-$56.5M |
| 5 |
Dimensional Fund Advisors
Austin,
Texas
|
-$39.9M |
MASI Hedge Fund Activity: Q3 2025 in Review
358 of the 7,621 institutional investors tracked by Wall St. Rank reported a position in Masimo (MASI) for Q3 2025, worth a combined $8.29B — down 14% from $9.68B a quarter earlier.
Sellers outnumbered buyers: 64 funds closed out of MASI and 47 opened new positions — a net loss of 17 holders — while 121 trimmed existing stakes and 119 added.
The largest buyer was Squarepoint, adding an estimated $82.8M. The largest seller was Holocene Advisors, exiting entirely with an estimated $209M sold.
- 358 institutional investors held Masimo (MASI) as of Q3 2025, down from 378 in Q2 2025.
- Funds reported $8.29B of Masimo stock for Q3 2025, down 14% quarter-over-quarter.
- 47 funds opened new Masimo positions in Q3 2025 and 64 closed out, a net change of -17 holders.
- The largest Masimo buyer in Q3 2025 was Squarepoint, an estimated $82.8M added.
- The largest Masimo seller in Q3 2025 was Holocene Advisors, an estimated $209M sold.
Based on aggregated 13F filings for Q3 2025.