BC
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Birchview Capital’s Prothena Corp PRTA Stock Holding History

Birchview Capital’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 		$4.4M Hold
449,019
– – 2.06% 12
2026
Q1 		$4.36M Buy
449,019
+8,000
+2% +$73.3K 2.48% 10
2025
Q4 		$4.21M Sell
441,019
-108,000
-20% -$1.1M 2.47% 11
2025
Q3 		$5.36M Buy
549,019
+98,000
+22% +$753K 4.05% 4
2025
Q2 		$2.74M Buy
451,019
+118,045
+35% +$886K 2.72% 8
2025
Q1 		$4.12M Buy
332,974
+28,400
+9% +$402K 3.58% 4
2024
Q4 		$4.22M Buy
304,574
+95,000
+45% +$1.5M 3.43% 5
2024
Q3 		$3.51M Buy
209,574
+6,000
+3% +$129K 3.04% 6
2024
Q2 		$4.2M Buy
203,574
+34,000
+20% +$736K 3.88% 6
2024
Q1 		$4.2M Hold
169,574
– – 3.42% 7
2023
Q4 		$6.16M Hold
169,574
– – 4.82% 5
2023
Q3 		$8.18M Buy
169,574
+13,463
+9% +$800K 6.95% 4
2023
Q2 		$10.7M Buy
156,111
+27,716
+22% +$1.79M 7.99% 2
2023
Q1 		$6.22M Buy
128,395
+1,200
+0.9% +$63.4K 4.87% 4
2022
Q4 		$7.66M Buy
127,195
+8,250
+7% +$483K 5.41% 4
2022
Q3 		$7.21M Buy
118,945
+16,397
+16% +$518K 5.08% 4
2022
Q2 		$2.78M Buy
102,548
+60,570
+144% +$1.77M 2.03% 10
2022
Q1 		$1.53M Buy
41,978
+1,731
+4% +$62.4K 1.11% 16
2021
Q4 		$1.99M Hold
40,247
– – 1.28% 14
2021
Q3 		$2.87M Buy
40,247
+10,000
+33% +$621K 1.95% 11
2021
Q2 		$1.55M Buy
+30,247
New +$944K 0.93% 18
2017
Q4 		– Sell
-3,632
Closed -$235K – 44
2017
Q3 		$235K Buy
+3,632
New +$222K 0.12% 33

Other funds holding PRTA

Fidelity Investments
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
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
Acadian Asset Management
Acadian Asset Management Boston, Massachusetts $84.2B AUM 55.88% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
D.E. Shaw & Co
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
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

Birchview Capital's PRTA Position: Q2 2026 in Review

Birchview Capital held its Prothena Corp (PRTA) position steady in Q2 2026 at 449,019 shares worth $4.4M. The position accounts for 2.06% of the portfolio, ranked #12.

Birchview Capital first reported a position in PRTA in Q3 2017 and has held it in 22 quarters since. The position peaked at $10.7M in Q2 2023. 188 funds tracked by Wall St. Rank hold PRTA as of Q2 2026.

  • Birchview Capital held 449,019 shares of Prothena Corp worth $4.4M as of Q2 2026.
  • Birchview Capital left its Prothena Corp share count unchanged in Q2 2026.
  • Prothena Corp made up 2.06% of Birchview Capital's portfolio in Q2 2026, its #12 holding.
  • Birchview Capital first reported a position in Prothena Corp in Q3 2017 and has held it in 22 quarters since.
  • Birchview Capital's Prothena Corp position peaked at $10.7M in Q2 2023.
  • 188 funds tracked by Wall St. Rank held Prothena Corp as of Q2 2026.

Based on Birchview Capital's 13F filing for Q2 2026, filed 14 Aug 2026.