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SION

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.

New
Increased
Maintained
Reduced
Closed

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%)

Holders
78
Holders Change
+13
Holders Change %
+20%
% of All Funds
1.02%
Holding in Top 10
4
Holding in Top 10 Change
–
Holding in Top 10 Change %
–
% of All Funds
0.05%
New
19
Increased
20
Reduced
19
Closed
6
Calls
–
Puts
–
Net Calls
–
Net Calls Change
–

Top Buyers

Rank Fund Capital Flow
1
Vanguard Group
Vanguard Group
Pennsylvania
+$11.2M
2
Jennison Associates
Jennison Associates
New York
+$5.32M
3
BlackRock
BlackRock
New York
+$4.51M
4
Millennium Management
Millennium Management
New York
+$4.35M
5
State Street
State Street
Massachusetts
+$2.52M

Top Sellers

Rank Fund Capital Flow
1
B
Braidwell
Connecticut
-$16.7M
2
Franklin Resources
Franklin Resources
California
-$5.61M
3
JP Morgan Chase
JP Morgan Chase
New York
-$5.28M
4
T. Rowe Price Associates
T. Rowe Price Associates
Maryland
-$4.86M
5
Prudential Financial
Prudential Financial
New Jersey
-$2.35M
Name Holding Trade Value Shares
Change 		Change in
Stake
SCM
26
Silverarc Capital Management
Massachusetts
$3.2M -$1.68M -77,214 -42%
RSCM
27
Rock Springs Capital Management
Maryland
$2.92M – – –
Northern Trust
28
Northern Trust
Illinois
$2.87M +$127K +5,821 +6%
TD Asset Management
29
TD Asset Management
Ontario, Canada
$2.56M +$807K +37,116 +74%
DCM
30
Driehaus Capital Management
Illinois
$2.47M – – –
LP
31
Longaeva Partners
Illinois
$1.81M +$1.34M +61,457 New
Holocene Advisors
32
Holocene Advisors
New York
$1.47M – – –
UBS Group
33
UBS Group
Switzerland
$1.37M -$102K -4,701 -9%
Wellington Management Group
34
Wellington Management Group
Massachusetts
$1.24M +$919K +42,234 New
Citadel Advisors
35
Citadel Advisors
Florida
$1.06M -$2.04M -93,989 -72%
Manulife (Manufacturers Life Insurance)
36
Manulife (Manufacturers Life Insurance)
Ontario, Canada
$943K -$130K -5,958 -16%
Polen Capital Management
37
Polen Capital Management
Florida
$919K +$311K +14,283 +84%
Marshall Wace
38
Marshall Wace
United Kingdom
$885K +$655K +30,103 New
Bank of New York Mellon
39
Bank of New York Mellon
New York
$808K +$72.5K +3,332 +14%
Morgan Stanley
40
Morgan Stanley
New York
$672K -$461K -21,181 -48%
Barclays
41
Barclays
United Kingdom
$519K -$117K -5,379 -23%
RhumbLine Advisers
42
RhumbLine Advisers
Massachusetts
$507K -$9.36K -430 -2%
N
43
Nuveen
North Carolina
$472K – – –
Renaissance Technologies
44
Renaissance Technologies
New York
$429K -$248K -11,400 -44%
Goldman Sachs
45
Goldman Sachs
New York
$358K -$737K -33,870 -74%
Squarepoint
46
Squarepoint
New York
$299K +$221K +10,162 New
Deutsche Bank
47
Deutsche Bank
Germany
$282K – – –
JG
48
Jain Global
New York
$250K +$185K +8,513 New
MIM
49
MetLife Investment Management
New Jersey
$236K – – –
Wells Fargo
50
Wells Fargo
California
$223K +$26.2K +1,202 +19%
1
2
3 4

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.