Sionna Therapeutics
SION
78 hedge funds and large institutions have $1.26B invested in Sionna Therapeutics in 2025 Q3 according to their latest regulatory filings, with 19 funds opening new positions, 20 increasing their positions, 19 reducing their positions, and 6 closing their positions.
217% more first-time investments, than exits
New positions opened: 19 | Existing positions closed: 6
67% more capital invested
Capital invested by funds: $754M → $1.26B (+$506M)
20% more funds holding
Funds holding: 65 → 78 (+13)
5% more repeat investments, than reductions
Existing positions increased: 20 | Existing positions reduced: 19
0% more funds holding in top 10
Funds holding in top 10: 4 → 4 (0)
1.41% less ownership
Funds ownership: 98.47% → 97.06% (-1.4%)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Vanguard Group
Malvern,
Pennsylvania
|
+$11.2M |
| 2 |
Jennison Associates
New York
|
+$5.32M |
| 3 |
BlackRock
New York
|
+$4.51M |
| 4 |
Millennium Management
New York
|
+$4.35M |
| 5 |
State Street
Boston,
Massachusetts
|
+$2.52M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
B
Braidwell
Stamford,
Connecticut
|
-$16.7M |
| 2 |
Franklin Resources
San Mateo,
California
|
-$5.61M |
| 3 |
JP Morgan Chase
New York
|
-$5.28M |
| 4 |
T. Rowe Price Associates
Baltimore,
Maryland
|
-$4.86M |
| 5 |
Prudential Financial
Newark,
New Jersey
|
-$2.35M |
| Name | Holding | Trade Value |
Shares Change |
Change in Stake |
|
|---|---|---|---|---|---|
|
AF
76
Allworth Financial
Folsom,
California
| $648 | +$479 | +22 | New |
|
|
EWA
77
EverSource Wealth Advisors
Birmingham,
Alabama
| $588 | +$435 | +20 | New |
|
78
PNC Financial Services Group
Pittsburgh,
Pennsylvania
| $147 | +$109 | +5 | New |
|
|
79
Prudential Financial
Newark,
New Jersey
| – | -$2.35M | -135,185 | Closed |
|
|
WP
80
Woodline Partners
San Francisco,
California
| – | -$1.39M | -80,000 | Closed |
|
|
BAM
81
Bosun Asset Management
Chicago,
Illinois
| – | -$295K | -16,975 | Closed |
|
82
Susquehanna International Group
Bala Cynwyd,
Pennsylvania
| – | -$257K | -14,834 | Closed |
|
83
Commonwealth Equity Services
Waltham,
Massachusetts
| – | -$243K | -14,017 | Closed |
|
|
SO
84
STRS Ohio
Columbus,
Ohio
| – | -$39.9K | -2,300 | Closed |
|
SION Hedge Fund Activity: Q3 2025 in Review
78 of the 7,621 institutional investors tracked by Wall St. Rank reported a position in Sionna Therapeutics (SION) for Q3 2025, worth a combined $1.26B — up 67% from $754M a quarter earlier.
Buyers outnumbered sellers: 19 funds opened new SION positions and 6 closed out — a net gain of 13 holders — while 20 added to existing stakes and 19 trimmed.
The largest buyer was Vanguard Group, adding an estimated $11.2M. The largest seller was Braidwell, cutting an estimated $16.7M.
- 78 institutional investors held Sionna Therapeutics (SION) as of Q3 2025, up from 65 in Q2 2025.
- Funds reported $1.26B of Sionna Therapeutics stock for Q3 2025, up 67% quarter-over-quarter.
- 19 funds opened new Sionna Therapeutics positions in Q3 2025 and 6 closed out, a net change of +13 holders.
- The largest Sionna Therapeutics buyer in Q3 2025 was Vanguard Group, an estimated $11.2M added.
- The largest Sionna Therapeutics seller in Q3 2025 was Braidwell, an estimated $16.7M sold.
Based on aggregated 13F filings for Q3 2025.