Prothena Corp
PRTA
161 hedge funds and large institutions have $647M invested in Prothena Corp in 2025 Q1 according to their latest regulatory filings, with 16 funds opening new positions, 42 increasing their positions, 59 reducing their positions, and 24 closing their positions.
180% more call options, than puts
Call options by funds: $3.5M | Put options by funds: $1.25M
0% more funds holding in top 10
Funds holding in top 10: 3 → 3 (0)
2.28% less ownership
Funds ownership: 99.46% → 97.18% (-2.3%)
5% less funds holding
Funds holding: 170 → 161 (-9)
13% less capital invested
Capital invested by funds: $741M → $647M (-$94.1M)
29% less repeat investments, than reductions
Existing positions increased: 42 | Existing positions reduced: 59
33% less first-time investments, than exits
New positions opened: 16 | Existing positions closed: 24
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Nordea Investment Management
Stockholm,
Sweden
|
+$4.35M |
| 2 |
SL
Siren LLC
Greenwich,
Connecticut
|
+$2.6M |
| 3 |
DA
DCF Advisers
Greenwich,
Connecticut
|
+$1.29M |
| 4 |
Jane Street
New York
|
+$1.09M |
| 5 |
Wellington Management Group
Boston,
Massachusetts
|
+$971K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
State Street
Boston,
Massachusetts
|
-$4.81M |
| 2 |
T. Rowe Price Associates
Baltimore,
Maryland
|
-$3.25M |
| 3 |
Federated Hermes
Pittsburgh,
Pennsylvania
|
-$2.83M |
| 4 |
RSCM
Rock Springs Capital Management
Baltimore,
Maryland
|
-$2.15M |
| 5 |
Vanguard Group
Malvern,
Pennsylvania
|
-$1.9M |
PRTA Hedge Fund Activity: Q1 2025 in Review
161 of the 7,459 institutional investors tracked by Wall St. Rank reported a position in Prothena Corp (PRTA) for Q1 2025, worth a combined $647M — down 13% from $741M a quarter earlier.
Sellers outnumbered buyers: 24 funds closed out of PRTA and 16 opened new positions — a net loss of 8 holders — while 59 trimmed existing stakes and 42 added.
The largest buyer was Nordea Investment Management, opening a new position worth an estimated $4.35M. The largest seller was State Street, cutting an estimated $4.81M.
- 161 institutional investors held Prothena Corp (PRTA) as of Q1 2025, down from 170 in Q4 2024.
- Funds reported $647M of Prothena Corp stock for Q1 2025, down 13% quarter-over-quarter.
- 16 funds opened new Prothena Corp positions in Q1 2025 and 24 closed out, a net change of -8 holders.
- The largest Prothena Corp buyer in Q1 2025 was Nordea Investment Management, an estimated $4.35M added.
- The largest Prothena Corp seller in Q1 2025 was State Street, an estimated $4.81M sold.
Based on aggregated 13F filings for Q1 2025.