Caption Management’s Prothena Corp PRTA Stock Holding History

Caption 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
2025 Q1	–	Sell	-87,900	Closed	-$1.22M	–	1934
2024 Q4	$1.22M	Buy	+87,900	New	+$1.39M	0.01%	858
2024 Q1	–	Sell	-44,600	Closed	-$1.62M	–	1593
2023 Q4	$1.62M	Sell	44,600 -19,300	-30%	-$743K	0.02%	674
2023 Q3	$3.08M	Buy	63,900 +49,000	+329%	+$2.91M	0.05%	472
2023 Q2	$1.02M	Buy	+14,900	New	+$961K	0.02%	659
2023 Q1	–	Sell	-35,000	Closed	-$2.11M	–	1453
2022 Q4	$2.11M	Buy	+35,000	New	+$2.05M	0.03%	548
2021 Q3	–	Sell	-30,000	Closed	-$1.54M	–	1736
2021 Q2	$1.54M	Buy	30,000 +20,000	+200%	+$624K	0.02%	777
2021 Q1	$252K	Buy	+10,000	New	+$188K	0.01%	895

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

Caption Management's PRTA Position: Q1 2026 in Review

Caption Management sold out of Prothena Corp (PRTA) in Q1 2026, closing a stake of 61,009 shares — an estimated $583K sold.

Caption Management first reported a position in PRTA in Q1 2021 and held it in 6 quarters. The position peaked at $1.67M in Q4 2023. 185 funds tracked by Wall St. Rank hold PRTA as of Q1 2026.

Caption Management reported no remaining Prothena Corp position as of Q1 2026 after selling out during the quarter.
Caption Management sold 61,009 Prothena Corp shares in Q1 2026, an estimated $583K.
Caption Management first reported a position in Prothena Corp in Q1 2021 and held it in 6 quarters.
Caption Management's Prothena Corp position peaked at $1.67M in Q4 2023.
185 funds tracked by Wall St. Rank held Prothena Corp as of Q1 2026.

Based on Caption Management's 13F filing for Q1 2026, filed 15 May 2026.