Mirum Pharmaceuticals
MIRM
311 hedge funds and large institutions have $6.29B invested in Mirum Pharmaceuticals in 2026 Q1 according to their latest regulatory filings, with 69 funds opening new positions, 114 increasing their positions, 88 reducing their positions, and 34 closing their positions.
1,208% more call options, than puts
Call options by funds: $19.9M | Put options by funds: $1.52M
103% more first-time investments, than exits
New positions opened: 69 | Existing positions closed: 34
45% more funds holding in top 10
Funds holding in top 10: 11 → 16 (+5)
31% more capital invested
Capital invested by funds: $4.82B → $6.29B (+$1.47B)
30% more repeat investments, than reductions
Existing positions increased: 114 | Existing positions reduced: 88
11% more funds holding
Funds holding: 281 → 311 (+30)
5.62% less ownership
Funds ownership: 118.72% → 113.1% (-5.6%)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
+$124M |
| 2 |
TCM
TCG Crossover Management
Palo Alto,
California
|
+$94.1M |
| 3 |
FLSM
Frazier Life Sciences Management
Palo Alto,
California
|
+$83.2M |
| 4 |
Janus Henderson Group
London,
United Kingdom
|
+$82.8M |
| 5 |
Capital World Investors
Los Angeles,
California
|
+$68.1M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
D.E. Shaw & Co
New York
|
-$73.4M |
| 2 |
EAM
Eventide Asset Management
Boston,
Massachusetts
|
-$64.4M |
| 3 |
PCH
Polar Capital Holdings
London,
United Kingdom
|
-$48M |
| 4 |
Arrowstreet Capital
Boston,
Massachusetts
|
-$28.7M |
| 5 |
PA
Perceptive Advisors
New York
|
-$20.5M |
MIRM Hedge Fund Activity: Q1 2026 in Review
311 of the 8,126 institutional investors tracked by Wall St. Rank reported a position in Mirum Pharmaceuticals (MIRM) for Q1 2026, worth a combined $6.29B — up 31% from $4.82B a quarter earlier.
Buyers outnumbered sellers: 69 funds opened new MIRM positions and 34 closed out — a net gain of 35 holders — while 114 added to existing stakes and 88 trimmed.
The largest buyer was Fidelity Investments, adding an estimated $124M. The largest seller was D.E. Shaw & Co, cutting an estimated $73.4M.
- 311 institutional investors held Mirum Pharmaceuticals (MIRM) as of Q1 2026, up from 281 in Q4 2025.
- Funds reported $6.29B of Mirum Pharmaceuticals stock for Q1 2026, up 31% quarter-over-quarter.
- 69 funds opened new Mirum Pharmaceuticals positions in Q1 2026 and 34 closed out, a net change of +35 holders.
- The largest Mirum Pharmaceuticals buyer in Q1 2026 was Fidelity Investments, an estimated $124M added.
- The largest Mirum Pharmaceuticals seller in Q1 2026 was D.E. Shaw & Co, an estimated $73.4M sold.
Based on aggregated 13F filings for Q1 2026.