Millennium Management
PRTA icon

Millennium Management’s Prothena Corp PRTA Stock Holding History

Millennium 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
Q1 		$489K Sell
50,300
-27,100
-35% -$248K ﹤0.01% 4784
2025
Q4 		$739K Buy
+77,400
New +$788K ﹤0.01% 4683
2023
Q3 		– Sell
-10,200
Closed -$696K – 6461
2023
Q2 		$696K Buy
+10,200
New +$658K ﹤0.01% 4312
2022
Q4 		– Sell
-4,000
Closed -$243K – 6935
2022
Q3 		$243K Buy
+4,000
New +$126K ﹤0.01% 5524
2022
Q1 		– Sell
-10,000
Closed -$494K – 7366
2021
Q4 		$494K Buy
+10,000
New +$555K ﹤0.01% 5054
2021
Q3 		– Sell
-66,700
Closed -$3.43M – 7142
2021
Q2 		$3.43M Buy
66,700
+46,700
+234% +$1.46M ﹤0.01% 3275
2021
Q1 		$502K Buy
+20,000
New +$376K ﹤0.01% 4825
2020
Q1 		– Sell
-87,900
Closed -$1.39M – 4340
2019
Q4 		$1.39M Buy
+87,900
New +$943K ﹤0.01% 2826
2018
Q3 		– Sell
-155,000
Closed -$2.26M – 4198
2018
Q2 		$2.26M Buy
155,000
+85,100
+122% +$1.68M ﹤0.01% 2312
2018
Q1 		$2.08M Buy
+69,900
New +$2.54M ﹤0.01% 2285
2015
Q1 		– Sell
-50,000
Closed -$858K – 3993
2014
Q4 		$858K Sell
50,000
-263,100
-84% -$5.49M ﹤0.01% 2604
2014
Q3 		$5.49M Buy
313,100
+112,900
+56% +$2.39M 0.01% 1233
2014
Q2 		$3.3M Buy
200,200
+57,000
+40% +$1.43M 0.01% 1455
2014
Q1 		$3.98M Buy
+143,200
New +$4.62M 0.01% 1335

Other funds holding PRTA

Fidelity Investments
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
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
D.E. Shaw & Co
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
Acadian Asset Management Boston, Massachusetts $70.5B AUM 36% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
Morgan Stanley
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

Millennium Management's PRTA Position: Q1 2026 in Review

Millennium Management sold out of Prothena Corp (PRTA) in Q1 2026, closing a stake of 21,976 shares — an estimated $201K sold.

Millennium Management first reported a position in PRTA in Q3 2013 and held it in 47 quarters. The position peaked at $32M in Q1 2018. 185 funds tracked by Wall St. Rank hold PRTA as of Q1 2026.

  • Millennium Management reported no remaining Prothena Corp position as of Q1 2026 after selling out during the quarter.
  • Millennium Management sold 21,976 Prothena Corp shares in Q1 2026, an estimated $201K.
  • Millennium Management first reported a position in Prothena Corp in Q3 2013 and held it in 47 quarters.
  • Millennium Management's Prothena Corp position peaked at $32M in Q1 2018.
  • 185 funds tracked by Wall St. Rank held Prothena Corp as of Q1 2026.

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