Mariner
PRTA icon

Mariner’s Prothena Corp PRTA Stock Holding History

Mariner’s Portfolio PRTA Stock Details PRTA Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$6.12M Buy
625,095
+62,013
+11% +$612K 0.01% 955
2026
Q1 		$5.47M Sell
563,082
-14,856
-3% -$136K 0.01% 1022
2025
Q4 		$5.52M Sell
577,938
-12,959
-2% -$132K 0.01% 964
2025
Q3 		$5.77M Buy
590,897
+204,189
+53% +$1.57M 0.01% 864
2025
Q2 		$2.35M Buy
386,708
+32,058
+9% +$241K ﹤0.01% 1237
2025
Q1 		$4.39M Buy
354,650
+10,733
+3% +$152K 0.01% 861
2024
Q4 		$4.76M Buy
343,917
+20,704
+6% +$327K 0.01% 815
2024
Q3 		$5.41M Buy
323,213
+125,178
+63% +$2.69M 0.01% 751
2024
Q2 		$4.09M Buy
198,035
+21,069
+12% +$456K 0.01% 805
2024
Q1 		$4.38M Sell
176,966
-1,458
-0.8% -$43.4K 0.01% 780
2023
Q4 		$6.48M Buy
178,424
+10,492
+6% +$404K 0.02% 601
2023
Q3 		$8.1M Buy
167,932
+32,870
+24% +$1.95M 0.02% 497
2023
Q2 		$9.22M Buy
135,062
+27,955
+26% +$1.8M 0.02% 461
2023
Q1 		$5.19M Buy
107,107
+80,180
+298% +$4.24M 0.02% 621
2022
Q4 		$1.62M Buy
26,927
+9,898
+58% +$580K 0.01% 1013
2022
Q3 		$1.03M Buy
17,029
+1,939
+13% +$61.3K ﹤0.01% 1033
2022
Q2 		$410K Sell
15,090
-59,040
-80% -$1.73M ﹤0.01% 1196
2022
Q1 		$2.71M Buy
74,130
+60,144
+430% +$2.17M 0.01% 649
2021
Q4 		$691K Buy
+13,986
New +$776K ﹤0.01% 929

Other funds holding PRTA

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
RCMNY
Rubric Capital Management (New York) New York $10.9B AUM 70.31% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
Acadian Asset Management
Acadian Asset Management Boston, Massachusetts $84.2B AUM 55.88% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
D.E. Shaw & Co
D.E. Shaw & Co New York $210B AUM 57.28% 1-Year Est. Return
ACM
ADAR1 Capital Management Austin, Texas $2.19B AUM 374.99% 1-Year Est. Return
Two Sigma Investments
Two Sigma Investments New York $138B AUM 41.87% 1-Year Est. Return
PAI
Palo Alto Investors Palo Alto, California $724M AUM 96.91% 1-Year Est. Return

Mariner's PRTA Position: Q2 2026 in Review

Mariner increased its Prothena Corp (PRTA) stake by 11% in Q2 2026, buying an estimated $612K and bringing the position to 625,095 shares worth $6.12M. The position accounts for 0.01% of the portfolio, ranked #955.

Mariner first reported a position in PRTA in Q4 2021 and has held it in 19 quarters since. The position peaked at $9.22M in Q2 2023. 188 funds tracked by Wall St. Rank hold PRTA as of Q2 2026.

  • Mariner held 625,095 shares of Prothena Corp worth $6.12M as of Q2 2026.
  • Mariner bought 62,013 Prothena Corp shares in Q2 2026, an estimated $612K.
  • Prothena Corp made up 0.01% of Mariner's portfolio in Q2 2026, its #955 holding.
  • Mariner first reported a position in Prothena Corp in Q4 2021 and has held it in 19 quarters since.
  • Mariner's Prothena Corp position peaked at $9.22M in Q2 2023.
  • 188 funds tracked by Wall St. Rank held Prothena Corp as of Q2 2026.

Based on Mariner's 13F filing for Q2 2026, filed 13 Aug 2026.