Sionna Therapeutics
SION
147 hedge funds and large institutions have $2.11B invested in Sionna Therapeutics in 2026 Q2 according to their latest regulatory filings, with 35 funds opening new positions, 58 increasing their positions, 39 reducing their positions, and 9 closing their positions.
289% more first-time investments, than exits
New positions opened: 35 | Existing positions closed: 9
49% more repeat investments, than reductions
Existing positions increased: 58 | Existing positions reduced: 39
20% more funds holding
Funds holding: 122 → 147 (+25)
16% more capital invested
Capital invested by funds: $1.82B → $2.11B (+$294M)
5.59% more ownership
Funds ownership: 100.91% → 106.5% (+5.6%)
25% less funds holding in top 10
Funds holding in top 10: 8 → 6 (-2)
82% less call options, than puts
Call options by funds: $1.49M | Put options by funds: $8.13M
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Adage Capital Partners
Boston,
Massachusetts
|
+$58M |
| 2 |
CC
Casdin Capital
New York
|
+$16M |
| 3 |
SL
Siren LLC
Greenwich,
Connecticut
|
+$12.4M |
| 4 |
DCM
Driehaus Capital Management
Chicago,
Illinois
|
+$12.4M |
| 5 |
State Street
Boston,
Massachusetts
|
+$10.6M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
O
OrbiMed
New York
|
-$39M |
| 2 |
DM
Deerfield Management
New York
|
-$11.6M |
| 3 |
Aberdeen Group
Edinburgh,
United Kingdom
|
-$11.2M |
| 4 |
Jennison Associates
New York
|
-$11.2M |
| 5 |
T. Rowe Price Associates
Baltimore,
Maryland
|
-$11.1M |
SION Hedge Fund Activity: Q2 2026 in Review
147 of the 8,318 institutional investors tracked by Wall St. Rank reported a position in Sionna Therapeutics (SION) for Q2 2026, worth a combined $2.11B — up 16% from $1.82B a quarter earlier.
Buyers outnumbered sellers: 35 funds opened new SION positions and 9 closed out — a net gain of 26 holders — while 58 added to existing stakes and 39 trimmed.
The largest buyer was Adage Capital Partners, adding an estimated $58M. The largest seller was OrbiMed, cutting an estimated $39M.
- 147 institutional investors held Sionna Therapeutics (SION) as of Q2 2026, up from 122 in Q1 2026.
- Funds reported $2.11B of Sionna Therapeutics stock for Q2 2026, up 16% quarter-over-quarter.
- 35 funds opened new Sionna Therapeutics positions in Q2 2026 and 9 closed out, a net change of +26 holders.
- The largest Sionna Therapeutics buyer in Q2 2026 was Adage Capital Partners, an estimated $58M added.
- The largest Sionna Therapeutics seller in Q2 2026 was OrbiMed, an estimated $39M sold.
Based on aggregated 13F filings for Q2 2026.