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	$600K	Buy	61,700 +31,600	+105%	+$290K	﹤0.01%	3175
2025 Q4	$287K	Sell	30,100 -130,200	-81%	-$1.33M	﹤0.01%	4051
2025 Q3	$1.56M	Buy	160,300 +65,700	+69%	+$505K	﹤0.01%	2565
2025 Q2	$574K	Buy	94,600 +70,400	+291%	+$528K	﹤0.01%	3272
2025 Q1	$299K	Sell	24,200 -6,800	-22%	-$96.2K	﹤0.01%	3589
2024 Q4	$429K	Buy	31,000 +17,800	+135%	+$281K	﹤0.01%	3306
2024 Q3	$221K	Hold	13,200	–	–	﹤0.01%	3520
2024 Q2	$272K	Sell	13,200 -8,800	-40%	-$190K	﹤0.01%	3135
2024 Q1	$545K	Sell	22,000 -69,800	-76%	-$2.08M	﹤0.01%	2644
2023 Q4	$3.34M	Buy	91,800 +82,300	+866%	+$3.17M	0.01%	1439
2023 Q3	$458K	Sell	9,500 -15,600	-62%	-$927K	﹤0.01%	3002
2023 Q2	$1.71M	Buy	25,100 +24,600	+4,920%	+$1.59M	0.01%	1859
2023 Q1	$24.2K	Sell	500 -16,300	-97%	-$861K	﹤0.01%	5382
2022 Q4	$1.01M	Buy	16,800 +4,400	+35%	+$258K	﹤0.01%	2398
2022 Q3	$752K	Buy	+12,400	New	+$392K	﹤0.01%	2855
2022 Q2	–	Sell	-4,900	Closed	-$179K	–	8372
2022 Q1	$179K	Sell	4,900 -4,400	-47%	-$159K	﹤0.01%	4910
2021 Q4	$459K	Buy	9,300 +7,500	+417%	+$416K	﹤0.01%	4230
2021 Q3	$128K	Sell	1,800 -10,800	-86%	-$671K	﹤0.01%	5654
2021 Q2	$648K	Sell	12,600 -46,500	-79%	-$1.45M	﹤0.01%	3926
2021 Q1	$1.49M	Sell	59,100 -700	-1%	-$13.2K	﹤0.01%	2779
2020 Q4	$718K	Buy	59,800 +46,100	+336%	+$545K	﹤0.01%	2942
2020 Q3	$137K	Buy	13,700 +1,000	+8%	+$12K	﹤0.01%	3952
2020 Q2	$133K	Buy	12,700 +12,100	+2,017%	+$134K	﹤0.01%	3688
2020 Q1	$6K	Buy	+600	New	+$7.27K	﹤0.01%	4735
2019 Q3	–	Sell	-3,000	Closed	-$32K	–	5453
2019 Q2	$32K	Sell	3,000 -11,000	-79%	-$113K	﹤0.01%	3992
2019 Q1	$170K	Sell	14,000 -50,900	-78%	-$636K	﹤0.01%	2816
2018 Q4	$668K	Sell	64,900 -22,600	-26%	-$269K	0.01%	1803
2018 Q3	$1.15M	Sell	87,500 -65,700	-43%	-$949K	0.01%	1598
2018 Q2	$2.23M	Buy	153,200 +98,300	+179%	+$1.94M	0.02%	1057
2018 Q1	$2.02M	Buy	54,900 +47,300	+622%	+$1.72M	0.02%	1003
2017 Q4	$285K	Sell	7,600 -24,800	-77%	-$1.26M	﹤0.01%	2683
2017 Q3	$2.1M	Buy	32,400 +20,100	+163%	+$1.23M	0.02%	1014
2017 Q2	$666K	Sell	12,300 -10,100	-45%	-$538K	0.01%	1747
2017 Q1	$1.25M	Sell	22,400 -12,200	-35%	-$641K	0.01%	1185
2016 Q4	$1.7M	Sell	34,600 -41,500	-55%	-$2.29M	0.02%	1005
2016 Q3	$4.56M	Buy	76,100 +42,900	+129%	+$2.3M	0.05%	450
2016 Q2	$1.16M	Buy	33,200 +15,200	+84%	+$662K	0.01%	1163
2016 Q1	$741K	Sell	18,000 -36,900	-67%	-$1.44M	0.01%	1402
2015 Q4	$3.74M	Sell	54,900 -5,300	-9%	-$320K	0.04%	501
2015 Q3	$2.73M	Sell	60,200 -38,000	-39%	-$2.21M	0.04%	615
2015 Q2	$5.17M	Buy	98,200 +32,700	+50%	+$1.29M	0.07%	315
2015 Q1	$2.5M	Buy	65,500 +40,800	+165%	+$1.05M	0.04%	532
2014 Q4	$513K	Sell	24,700 -13,600	-36%	-$284K	0.01%	1542
2014 Q3	$849K	Sell	38,300 -20,600	-35%	-$437K	0.01%	1220
2014 Q2	$1.33M	Buy	58,900 +18,700	+47%	+$468K	0.02%	952
2014 Q1	$1.54M	Buy	40,200 +34,200	+570%	+$1.1M	0.03%	785
2013 Q4	$159K	Buy	6,000 +5,000	+500%	+$125K	﹤0.01%	2631
2013 Q3	$20K	Buy	+1,000	New	+$17.7K	﹤0.01%	4181

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.