Simplex Trading
PRTA icon

Simplex Trading’s Prothena Corp PRTA Stock Holding History

Simplex Trading’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 		$989K Buy
101,000
+77,700
+333% +$767K ﹤0.01% 2789
2026
Q1 		$226K Sell
23,300
-2,600
-10% -$23.8K ﹤0.01% 4165
2025
Q4 		$247K Sell
25,900
-37,600
-59% -$383K ﹤0.01% 4010
2025
Q3 		$619K Sell
63,500
-123,700
-66% -$951K ﹤0.01% 3561
2025
Q2 		$1.14M Buy
187,200
+170,100
+995% +$1.28M ﹤0.01% 2648
2025
Q1 		$211K Sell
17,100
-31,000
-64% -$438K ﹤0.01% 4265
2024
Q4 		$666K Buy
48,100
+27,800
+137% +$439K ﹤0.01% 3255
2024
Q3 		$339K Buy
20,300
+8,400
+71% +$181K ﹤0.01% 4008
2024
Q2 		$245K Hold
11,900
– – ﹤0.01% 4454
2024
Q1 		$294K Sell
11,900
-81,200
-87% -$2.42M ﹤0.01% 4420
2023
Q4 		$3.38M Buy
93,100
+89,100
+2,228% +$3.43M ﹤0.01% 1894
2023
Q3 		$193K Buy
4,000
+1,500
+60% +$89.1K ﹤0.01% 4394
2023
Q2 		$170K Sell
2,500
-30,100
-92% -$1.94M ﹤0.01% 4484
2023
Q1 		$1.58M Sell
32,600
-7,500
-19% -$396K ﹤0.01% 2151
2022
Q4 		$2.42M Buy
40,100
+19,700
+97% +$1.15M ﹤0.01% 1725
2022
Q3 		$1.24M Sell
20,400
-32,200
-61% -$1.02M ﹤0.01% 2410
2022
Q2 		$1.43M Buy
52,600
+38,700
+278% +$1.13M ﹤0.01% 2218
2022
Q1 		$508K Sell
13,900
-6,900
-33% -$249K ﹤0.01% 3822
2021
Q4 		$1.03M Buy
20,800
+5,500
+36% +$305K ﹤0.01% 2815
2021
Q3 		$807K Buy
15,300
+300
+2% +$18.6K ﹤0.01% 3390
2021
Q2 		$771K Buy
15,000
+14,963
+40,441% +$467K ﹤0.01% 3512
2021
Q1 		$92K Buy
37
+14
+61% +$263 ﹤0.01% 5871
2020
Q4 		$27K Buy
+23
New +$272 ﹤0.01% 6753
2020
Q3 		– Sell
-307
Closed -$321K – 8343
2020
Q2 		$321K Buy
307
+53
+21% +$589 ﹤0.01% 3447
2020
Q1 		$271K Buy
254
+47
+23% +$569 ﹤0.01% 3249
2019
Q4 		$327K Buy
+207
New +$2.22K ﹤0.01% 3183
2019
Q2 		– Sell
-2
Closed -$2K – 7629
2019
Q1 		$2K Sell
2
-558
-100% -$6.97K ﹤0.01% 6808
2018
Q4 		$576K Buy
560
+2
+0.4% +$24 ﹤0.01% 2091
2018
Q3 		$729K Sell
558
-364
-39% -$5.26K ﹤0.01% 2206
2018
Q2 		$1.34M Buy
922
+678
+278% +$13.4K 0.01% 1504
2018
Q1 		$132K Buy
244
+86
+54% +$3.13K 0.01% 1577
2017
Q4 		$3K Buy
+158
New +$8.04K ﹤0.01% 4971
2017
Q3 		– Sell
-83
Closed -$23K – 6481
2017
Q2 		$23K Sell
83
-22
-21% -$1.17K ﹤0.01% 3169
2017
Q1 		$13K Sell
105
-100
-49% -$5.25K ﹤0.01% 3724
2016
Q4 		$5K Sell
205
-42
-17% -$2.32K ﹤0.01% 4378
2016
Q3 		$45K Sell
247
-298
-55% -$16K ﹤0.01% 2198
2016
Q2 		$26K Buy
545
+223
+69% +$9.71K ﹤0.01% 2670
2016
Q1 		$58K Buy
322
+148
+85% +$5.79K ﹤0.01% 1833
2015
Q4 		$8K Buy
+174
New +$10.5K ﹤0.01% 3522
2015
Q3 		– Sell
-67
Closed -$91K – 6052
2015
Q2 		$91K Buy
67
+48
+253% +$1.89K 0.01% 1265
2015
Q1 		$2K Buy
+19
New +$487 ﹤0.01% 4178

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

Simplex Trading's PRTA Position: Q2 2026 in Review

Simplex Trading sold out of Prothena Corp (PRTA) in Q2 2026, closing a stake of 1,303 shares — an estimated $12.9K sold.

Simplex Trading first reported a position in PRTA in Q4 2014 and held it in 31 quarters. The position peaked at $1.43M in Q3 2022. 188 funds tracked by Wall St. Rank hold PRTA as of Q2 2026.

  • Simplex Trading reported no remaining Prothena Corp position as of Q2 2026 after selling out during the quarter.
  • Simplex Trading sold 1,303 Prothena Corp shares in Q2 2026, an estimated $12.9K.
  • Simplex Trading first reported a position in Prothena Corp in Q4 2014 and held it in 31 quarters.
  • Simplex Trading's Prothena Corp position peaked at $1.43M in Q3 2022.
  • 188 funds tracked by Wall St. Rank held Prothena Corp as of Q2 2026.

Based on Simplex Trading's 13F filing for Q2 2026, filed 12 Aug 2026.