MBX Biosciences
157 hedge funds and large institutions have $1.57B invested in MBX Biosciences in 2026 Q1 according to their latest regulatory filings, with 39 funds opening new positions, 43 increasing their positions, 47 reducing their positions, and 18 closing their positions.
153% more call options, than puts
Call options by funds: $3.68M | Put options by funds: $1.46M
117% more first-time investments, than exits
New positions opened: 39 | Existing positions closed: 18
14% more funds holding
Funds holding: 138 → 157 (+19)
2.72% more ownership
Funds ownership: 107.85% → 110.58% (+2.7%)
3% more capital invested
Capital invested by funds: $1.53B → $1.57B (+$40.7M)
9% less repeat investments, than reductions
Existing positions increased: 43 | Existing positions reduced: 47
14% less funds holding in top 10
Funds holding in top 10: 7 → 6 (-1)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
+$99.3M |
| 2 |
PCH
Polar Capital Holdings
London,
United Kingdom
|
+$55.2M |
| 3 |
AWA
Aaron Wealth Advisors
Chicago,
Illinois
|
+$37.3M |
| 4 |
CP
Caligan Partners
New York
|
+$28.9M |
| 5 |
B
Braidwell
Stamford,
Connecticut
|
+$16.1M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
EC
EcoR1 Capital
San Francisco,
California
|
-$45.8M |
| 2 |
Point72 Asset Management
Stamford,
Connecticut
|
-$21.5M |
| 3 |
DTC
Deep Track Capital
Greenwich,
Connecticut
|
-$16.7M |
| 4 |
DCM
Driehaus Capital Management
Chicago,
Illinois
|
-$13.3M |
| 5 |
D.E. Shaw & Co
New York
|
-$13M |
MBX Hedge Fund Activity: Q1 2026 in Review
157 of the 8,191 institutional investors tracked by Wall St. Rank reported a position in MBX Biosciences (MBX) for Q1 2026, worth a combined $1.57B — up 2.7% from $1.53B a quarter earlier.
Buyers outnumbered sellers: 39 funds opened new MBX positions and 18 closed out — a net gain of 21 holders — while 43 added to existing stakes and 47 trimmed.
The largest buyer was Fidelity Investments, adding an estimated $99.3M. The largest seller was EcoR1 Capital, cutting an estimated $45.8M.
- 157 institutional investors held MBX Biosciences (MBX) as of Q1 2026, up from 138 in Q4 2025.
- Funds reported $1.57B of MBX Biosciences stock for Q1 2026, up 2.7% quarter-over-quarter.
- 39 funds opened new MBX Biosciences positions in Q1 2026 and 18 closed out, a net change of +21 holders.
- The largest MBX Biosciences buyer in Q1 2026 was Fidelity Investments, an estimated $99.3M added.
- The largest MBX Biosciences seller in Q1 2026 was EcoR1 Capital, an estimated $45.8M sold.
Based on aggregated 13F filings for Q1 2026.