Question 1

Does Simplex Trading own PRTA stock?

Accepted Answer

No. Simplex Trading exited its PRTA (Prothena) position in Q2 2026. Its Q1 2026 13F listed 1,303 shares worth $12,665.

Question 2

How many shares of PRTA does Simplex Trading own?

Accepted Answer

None since Q2 2026, when Simplex Trading exited the position. Its Q1 2026 13F listed 1,303 shares worth $12,665.

Question 3

What is Simplex Trading's PRTA position worth?

Accepted Answer

Simplex Trading's PRTA position was worth $12,665 in its Q1 2026 13F, before the exit in Q2 2026.

Question 4

Is Simplex Trading buying or selling PRTA?

Accepted Answer

In Q2 2026, Simplex Trading exited its entire PRTA position.

Question 5

When did Simplex Trading first buy PRTA?

Accepted Answer

Simplex Trading already held PRTA in its Q1 2019 13F, the earliest on record, and listed it in 20 quarterly 13F filings.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Exited	0	-100.0%	$0	0.0%	$9.79	0
2026-Q1	Decreased	1,303	-32.4%	$12,665	0.0%	$9.72	0
2025-Q4	Decreased	1,927	-95.4%	$18,402	0.0%	$9.55	0
2025-Q3	Decreased	42,044	-2.8%	$410,000	0.0%	$9.76	0
2025-Q2	New	43,264	—	$262,000	0.0%	$6.07	32
2024-Q4	Exited	0	-100.0%	$0	0.0%	$13.85	0
2024-Q3	Increased	5,977	+163.7%	$99,000	0.0%	$16.73	35