Campbell & Co Investment Adviser’s Prothena Corp PRTA Stock Holding History

Campbell & Co Investment Adviser’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	$669K	Sell	68,345 -74,242	-52%	-$733K	0.04%	687
2026 Q1	$1.39M	Buy	142,587 +48,432	+51%	+$444K	0.08%	388
2025 Q4	$899K	Buy	+94,155	New	+$959K	0.04%	604
2023 Q1	–	Sell	-8,527	Closed	-$514K	–	992
2022 Q4	$514K	Buy	8,527 +104	+1%	+$6.09K	0.12%	301
2022 Q3	$511K	Buy	+8,423	New	+$266K	0.12%	309
2021 Q4	–	Sell	-8,400	Closed	-$598K	–	773
2021 Q3	$598K	Buy	+8,400	New	+$522K	0.19%	166
2020 Q3	–	Sell	-37,046	Closed	-$388K	–	460
2020 Q2	$388K	Buy	+37,046	New	+$412K	0.49%	54
2019 Q4	–	Sell	-47,901	Closed	-$376K	–	811
2019 Q3	$376K	Buy	47,901 +27,601	+136%	+$245K	0.14%	286
2019 Q2	$215K	Buy	+20,300	New	+$208K	0.1%	439

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 $3.38T AUM 44.17% 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

Campbell & Co Investment Adviser's PRTA Position: Q2 2026 in Review

Campbell & Co Investment Adviser reduced its Prothena Corp (PRTA) stake by 52% in Q2 2026, selling an estimated $733K and leaving 68,345 shares worth $669K. The position accounts for 0.04% of the portfolio, ranked #687.

Campbell & Co Investment Adviser first reported a position in PRTA in Q2 2019 and has held it in 9 quarters since. The position peaked at $1.39M in Q1 2026. 187 funds tracked by Wall St. Rank hold PRTA as of Q2 2026.

Campbell & Co Investment Adviser held 68,345 shares of Prothena Corp worth $669K as of Q2 2026.
Campbell & Co Investment Adviser sold 74,242 Prothena Corp shares in Q2 2026, an estimated $733K.
Prothena Corp made up 0.04% of Campbell & Co Investment Adviser's portfolio in Q2 2026, its #687 holding.
Campbell & Co Investment Adviser first reported a position in Prothena Corp in Q2 2019 and has held it in 9 quarters since.
Campbell & Co Investment Adviser's Prothena Corp position peaked at $1.39M in Q1 2026.
187 funds tracked by Wall St. Rank held Prothena Corp as of Q2 2026.

Based on Campbell & Co Investment Adviser's 13F filing for Q2 2026, filed 3 Aug 2026.