Masimo
MASI
MASI was delisted on the 9th of June, 2026.
356 hedge funds and large institutions have $4.18B invested in Masimo in 2023 Q3 according to their latest regulatory filings, with 59 funds opening new positions, 81 increasing their positions, 158 reducing their positions, and 117 closing their positions.
259% more call options, than puts
Call options by funds: $208M | Put options by funds: $58M
3.16% more ownership
Funds ownership: 87.06% → 90.23% (+3.2%)
14% less funds holding
Funds holding: 415 → 356 (-59)
33% less funds holding in top 10
Funds holding in top 10: 6 → 4 (-2)
45% less capital invested
Capital invested by funds: $7.56B → $4.18B (-$3.38B)
49% less repeat investments, than reductions
Existing positions increased: 81 | Existing positions reduced: 158
50% less first-time investments, than exits
New positions opened: 59 | Existing positions closed: 117
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Massachusetts Financial Services
Boston,
Massachusetts
|
+$176M |
| 2 |
EC
Eminence Capital
New York
|
+$121M |
| 3 |
JSP
Jackson Square Partners
Larkspur,
California
|
+$85.6M |
| 4 |
SHCM
Sachem Head Capital Management
New York
|
+$73.8M |
| 5 |
Capital Research Global Investors
Los Angeles,
California
|
+$55.9M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
-$222M |
| 2 |
Fundsmith LLP
London,
United Kingdom
|
-$120M |
| 3 |
BlackRock
New York
|
-$82.4M |
| 4 |
GCM
Geneva Capital Management
Milwaukee,
Wisconsin
|
-$50.1M |
| 5 |
Norges Bank
Oslo,
Norway
|
-$48.2M |
MASI Hedge Fund Activity: Q3 2023 in Review
356 of the 6,302 institutional investors tracked by Wall St. Rank reported a position in Masimo (MASI) for Q3 2023, worth a combined $4.18B — down 45% from $7.56B a quarter earlier.
Sellers outnumbered buyers: 117 funds closed out of MASI and 59 opened new positions — a net loss of 58 holders — while 158 trimmed existing stakes and 81 added.
The largest buyer was Massachusetts Financial Services, opening a new position worth an estimated $176M. The largest seller was Fidelity Investments, cutting an estimated $222M.
- 356 institutional investors held Masimo (MASI) as of Q3 2023, down from 415 in Q2 2023.
- Funds reported $4.18B of Masimo stock for Q3 2023, down 45% quarter-over-quarter.
- 59 funds opened new Masimo positions in Q3 2023 and 117 closed out, a net change of -58 holders.
- The largest Masimo buyer in Q3 2023 was Massachusetts Financial Services, an estimated $176M added.
- The largest Masimo seller in Q3 2023 was Fidelity Investments, an estimated $222M sold.
Based on aggregated 13F filings for Q3 2023.