Penbrook Management’s Prothena Corp PRTA Stock Holding History

Penbrook 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
2026 Q2	$2.66M	Hold	271,720	–	–	1.7%	15
2026 Q1	$2.64M	Buy	+271,720	New	+$2.49M	2%	12

Other funds holding PRTA

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 New York $6.73T AUM 46.02% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Acadian Asset Management Boston, Massachusetts $84.2B AUM 55.88% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

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 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

Penbrook Management's PRTA Position: Q2 2026 in Review

Penbrook Management held its Prothena Corp (PRTA) position steady in Q2 2026 at 271,720 shares worth $2.66M. The position accounts for 1.7% of the portfolio, ranked #15.

Penbrook Management first reported a position in PRTA in Q1 2026 and has held it in 2 quarters since. 188 funds tracked by Wall St. Rank hold PRTA as of Q2 2026.

Penbrook Management held 271,720 shares of Prothena Corp worth $2.66M as of Q2 2026.
Penbrook Management left its Prothena Corp share count unchanged in Q2 2026.
Prothena Corp made up 1.7% of Penbrook Management's portfolio in Q2 2026, its #15 holding.
Penbrook Management first reported a position in Prothena Corp in Q1 2026 and has held it in 2 quarters since.
188 funds tracked by Wall St. Rank held Prothena Corp as of Q2 2026.

Based on Penbrook Management's 13F filing for Q2 2026, filed 23 Jul 2026.