Group One Trading’s Prothena Corp PRTA Stock Holding History

Group One 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 Q1	$111K	Sell	11,400 -41,900	-79%	-$384K	﹤0.01%	4636
2025 Q4	$509K	Sell	53,300 -1,100	-2%	-$11.2K	﹤0.01%	3490
2025 Q3	$531K	Buy	54,400 +13,400	+33%	+$103K	﹤0.01%	3644
2025 Q2	$249K	Buy	41,000 +21,800	+114%	+$164K	﹤0.01%	4120
2025 Q1	$238K	Sell	19,200 -90,000	-82%	-$1.27M	﹤0.01%	3845
2024 Q4	$1.51M	Buy	109,200 +106,700	+4,268%	+$1.68M	﹤0.01%	2166
2024 Q3	$41.8K	Sell	2,500 -500	-17%	-$10.8K	﹤0.01%	4765
2024 Q2	$61.9K	Sell	3,000 -20,600	-87%	-$446K	﹤0.01%	4358
2024 Q1	$585K	Sell	23,600 -46,700	-66%	-$1.39M	﹤0.01%	2583
2023 Q4	$2.55M	Buy	70,300 +69,200	+6,291%	+$2.66M	0.01%	1666
2023 Q3	$53.1K	Sell	1,100 -2,400	-69%	-$143K	﹤0.01%	5046
2023 Q2	$239K	Buy	3,500 +1,600	+84%	+$103K	﹤0.01%	3761
2023 Q1	$92.1K	Sell	1,900 -15,400	-89%	-$814K	﹤0.01%	4375
2022 Q4	$1.04M	Sell	17,300 -48,300	-74%	-$2.83M	﹤0.01%	2375
2022 Q3	$3.98M	Sell	65,600 -2,200	-3%	-$69.6K	0.01%	1343
2022 Q2	$1.84M	Sell	67,800 -9,700	-13%	-$284K	﹤0.01%	2141
2022 Q1	$2.83M	Buy	77,500 +65,500	+546%	+$2.36M	﹤0.01%	2050
2021 Q4	$593K	Buy	12,000 +9,300	+344%	+$516K	﹤0.01%	3924
2021 Q3	$192K	Sell	2,700 -5,400	-67%	-$335K	﹤0.01%	5221
2021 Q2	$416K	Sell	8,100 -5,500	-40%	-$172K	﹤0.01%	4430
2021 Q1	$342K	Sell	13,600 -11,000	-45%	-$207K	﹤0.01%	4453
2020 Q4	$295K	Buy	24,600 +500	+2%	+$5.91K	﹤0.01%	3750
2020 Q3	$241K	Buy	+24,100	New	+$290K	﹤0.01%	3509
2020 Q2	–	Sell	-900	Closed	-$10K	–	6097
2020 Q1	$10K	Sell	900 -5,500	-86%	-$66.6K	﹤0.01%	4573
2019 Q4	$101K	Buy	+6,400	New	+$68.6K	﹤0.01%	3627
2019 Q3	–	Sell	-1,300	Closed	-$14K	–	5452
2019 Q2	$14K	Buy	+1,300	New	+$13.4K	﹤0.01%	4313
2019 Q1	–	Sell	-67,800	Closed	-$698K	–	5254
2018 Q4	$698K	Buy	67,800 +45,500	+204%	+$541K	0.01%	1773
2018 Q3	$292K	Sell	22,300 -10,000	-31%	-$144K	﹤0.01%	2727
2018 Q2	$471K	Sell	32,300 -20,300	-39%	-$401K	﹤0.01%	2343
2018 Q1	$1.93M	Buy	52,600 +49,200	+1,447%	+$1.79M	0.02%	1033
2017 Q4	$127K	Buy	3,400 +1,600	+89%	+$81.5K	﹤0.01%	3215
2017 Q3	$117K	Sell	1,800 -1,200	-40%	-$73.5K	﹤0.01%	3134
2017 Q2	$162K	Sell	3,000 -18,400	-86%	-$980K	﹤0.01%	2801
2017 Q1	$1.19M	Buy	21,400 +1,200	+6%	+$63K	0.01%	1212
2016 Q4	$994K	Buy	20,200 +2,700	+15%	+$149K	0.01%	1321
2016 Q3	$1.05M	Sell	17,500 -13,400	-43%	-$719K	0.01%	1253
2016 Q2	$1.08M	Buy	30,900 +10,900	+55%	+$475K	0.01%	1210
2016 Q1	$823K	Sell	20,000 -4,900	-20%	-$192K	0.01%	1325
2015 Q4	$1.7M	Sell	24,900 -26,600	-52%	-$1.6M	0.02%	973
2015 Q3	$2.33M	Buy	51,500 +22,000	+75%	+$1.28M	0.03%	695
2015 Q2	$1.55M	Buy	29,500 +24,800	+528%	+$979K	0.02%	902
2015 Q1	$179K	Sell	4,700 -7,600	-62%	-$195K	﹤0.01%	2459
2014 Q4	$255K	Sell	12,300 -6,900	-36%	-$144K	﹤0.01%	2106
2014 Q3	$425K	Buy	19,200 +2,300	+14%	+$48.8K	0.01%	1743
2014 Q2	$381K	Sell	16,900 -800	-5%	-$20K	0.01%	1862
2014 Q1	$678K	Sell	17,700 -28,000	-61%	-$903K	0.01%	1403
2013 Q4	$1.21M	Buy	45,700 +40,700	+814%	+$1.02M	0.02%	972
2013 Q3	$101K	Buy	+5,000	New	+$88.5K	﹤0.01%	3017

Other funds holding PRTA

Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

RCMNY

Rubric Capital Management (New York) New York $9.44B AUM 68.42% 1-Year Est. Return

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

D.E. Shaw & Co New York $166B AUM 43.98% 1-Year Est. Return

ACM

ADAR1 Capital Management Austin, Texas $1.7B AUM 340.85% 1-Year Est. Return

Acadian Asset Management Boston, Massachusetts $70.5B AUM 36% 1-Year Est. Return

VPM

Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM

Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return

PAI

Palo Alto Investors Palo Alto, California $654M AUM 77.8% 1-Year Est. Return

Group One Trading's PRTA Position: Q1 2026 in Review

Group One Trading opened a new position in Prothena Corp (PRTA) in Q1 2026: 3,416 shares worth $33.2K. The stake represents ﹤0.01% of the portfolio and ranks #5583 among its holdings. This is a return to the name: Group One Trading previously reported a position in PRTA as recently as Q3 2025.

Group One Trading first reported a position in PRTA in Q2 2013 and has held it in 40 quarters since. The position peaked at $1.93M in Q3 2016. 185 funds tracked by Wall St. Rank hold PRTA as of Q1 2026.

Group One Trading held 3,416 shares of Prothena Corp worth $33.2K as of Q1 2026.
Prothena Corp was a new Group One Trading position in Q1 2026.
Prothena Corp made up ﹤0.01% of Group One Trading's portfolio in Q1 2026, its #5583 holding.
Group One Trading first reported a position in Prothena Corp in Q2 2013 and has held it in 40 quarters since.
Group One Trading's Prothena Corp position peaked at $1.93M in Q3 2016.
185 funds tracked by Wall St. Rank held Prothena Corp as of Q1 2026.

Based on Group One Trading's 13F filing for Q1 2026, filed 13 May 2026.