Masimo
MASI
MASI was delisted on the 9th of June, 2026.
365 hedge funds and large institutions have $8.5B invested in Masimo in 2024 Q4 according to their latest regulatory filings, with 62 funds opening new positions, 117 increasing their positions, 118 reducing their positions, and 51 closing their positions.
70% more call options, than puts
Call options by funds: $21.3M | Put options by funds: $12.6M
33% more funds holding in top 10
Funds holding in top 10: 3 → 4 (+1)
27% more capital invested
Capital invested by funds: $6.72B → $8.5B (+$1.78B)
22% more first-time investments, than exits
New positions opened: 62 | Existing positions closed: 51
1.72% more ownership
Funds ownership: 94.33% → 96.05% (+1.7%)
1% more funds holding
Funds holding: 362 → 365 (+3)
1% less repeat investments, than reductions
Existing positions increased: 117 | Existing positions reduced: 118
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
+$212M |
| 2 |
Capital Research Global Investors
Los Angeles,
California
|
+$173M |
| 3 |
Massachusetts Financial Services
Boston,
Massachusetts
|
+$149M |
| 4 |
AllianceBernstein
Nashville,
Tennessee
|
+$139M |
| 5 |
Millennium Management
New York
|
+$59.8M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
AMG
Ace Management Global
Sao Paulo,
Brazil
|
-$145M |
| 2 |
FCM
Farallon Capital Management
San Francisco,
California
|
-$136M |
| 3 |
RI
RTW Investments
New York
|
-$123M |
| 4 |
Westfield Capital Management
Boston,
Massachusetts
|
-$98.7M |
| 5 |
Man Group
London,
United Kingdom
|
-$52.9M |
MASI Hedge Fund Activity: Q4 2024 in Review
365 of the 7,593 institutional investors tracked by Wall St. Rank reported a position in Masimo (MASI) for Q4 2024, worth a combined $8.5B — up 27% from $6.72B a quarter earlier.
Buyers outnumbered sellers: 62 funds opened new MASI positions and 51 closed out — a net gain of 11 holders — while 117 added to existing stakes and 118 trimmed.
The largest buyer was Fidelity Investments, adding an estimated $212M. The largest seller was Ace Management Global, cutting an estimated $145M.
- 365 institutional investors held Masimo (MASI) as of Q4 2024, up from 362 in Q3 2024.
- Funds reported $8.5B of Masimo stock for Q4 2024, up 27% quarter-over-quarter.
- 62 funds opened new Masimo positions in Q4 2024 and 51 closed out, a net change of +11 holders.
- The largest Masimo buyer in Q4 2024 was Fidelity Investments, an estimated $212M added.
- The largest Masimo seller in Q4 2024 was Ace Management Global, an estimated $145M sold.
Based on aggregated 13F filings for Q4 2024.