Acadian Asset Management
PRTA icon

Acadian Asset Management’s Prothena Corp PRTA Stock Holding History

Acadian Asset Management’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 		$19.7M Buy
2,010,645
+463,052
+30% +$4.57M 0.02% 429
2026
Q1 		$15M Buy
1,547,593
+110,235
+8% +$1.01M 0.02% 437
2025
Q4 		$13.7M Buy
1,437,358
+198,116
+16% +$2.02M 0.02% 415
2025
Q3 		$12.1M Buy
1,239,242
+221,065
+22% +$1.7M 0.02% 433
2025
Q2 		$6.18M Buy
+1,018,177
New +$7.64M 0.01% 535
2025
Q1 		– Sell
-4,565
Closed -$63K – 1779
2024
Q4 		$63K Buy
+4,565
New +$72K ﹤0.01% 1427
2022
Q1 		– Sell
-7,961
Closed -$393K – 1758
2021
Q4 		$393K Buy
7,961
+6,531
+457% +$362K ﹤0.01% 1069
2021
Q3 		$101K Buy
+1,430
New +$88.8K ﹤0.01% 1445
2021
Q2 		– Sell
-66,043
Closed -$1.66M – 2169
2021
Q1 		$1.66M Sell
66,043
-110,396
-63% -$2.08M 0.01% 792
2020
Q4 		$2.12M Sell
176,439
-33,578
-16% -$397K 0.01% 741
2020
Q3 		$2.1M Sell
210,017
-15,939
-7% -$192K 0.01% 655
2020
Q2 		$2.36M Buy
225,956
+15,702
+7% +$174K 0.01% 691
2020
Q1 		$2.25M Buy
210,254
+97,916
+87% +$1.19M 0.01% 576
2019
Q4 		$1.78M Buy
112,338
+56,769
+102% +$609K 0.01% 724
2019
Q3 		$435K Sell
55,569
-10,448
-16% -$92.8K ﹤0.01% 1127
2019
Q2 		$697K Buy
66,017
+13,849
+27% +$142K ﹤0.01% 906
2019
Q1 		$633K Buy
+52,168
New +$651K ﹤0.01% 1041
2015
Q2 		– Sell
-4,152
Closed -$158K – 1470
2015
Q1 		$158K Hold
4,152
– – ﹤0.01% 956
2014
Q4 		$86K Sell
4,152
-1,350
-25% -$28.2K ﹤0.01% 1018
2014
Q3 		$122K Buy
+5,502
New +$117K ﹤0.01% 814
2013
Q4 		– Sell
-7,290
Closed -$147K – 1094
2013
Q3 		$147K Sell
7,290
-20,544
-74% -$364K ﹤0.01% 778
2013
Q2 		$359K Buy
+27,834
New +$259K ﹤0.01% 636

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
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
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

Acadian Asset Management's PRTA Position: Q2 2026 in Review

Acadian Asset Management increased its Prothena Corp (PRTA) stake by 30% in Q2 2026, buying an estimated $4.57M and bringing the position to 2,010,645 shares worth $19.7M. The position accounts for 0.02% of the portfolio, ranked #429.

Acadian Asset Management first reported a position in PRTA in Q2 2013 and has held it in 22 quarters since. 188 funds tracked by Wall St. Rank hold PRTA as of Q2 2026.

  • Acadian Asset Management held 2,010,645 shares of Prothena Corp worth $19.7M as of Q2 2026.
  • Acadian Asset Management bought 463,052 Prothena Corp shares in Q2 2026, an estimated $4.57M.
  • Prothena Corp made up 0.02% of Acadian Asset Management's portfolio in Q2 2026, its #429 holding.
  • Acadian Asset Management first reported a position in Prothena Corp in Q2 2013 and has held it in 22 quarters since.
  • 188 funds tracked by Wall St. Rank held Prothena Corp as of Q2 2026.

Based on Acadian Asset Management's 13F filing for Q2 2026, filed 13 Aug 2026.