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Aaron Cowen’s Ultragenyx Pharmaceutical RARE Stock Holding History

Aaron Cowen’s Portfolio RARE Stock Details RARE Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		– Sell
-2,019,000
Closed -$46.4M – 105
2025
Q4 		$46.4M Hold
2,019,000
– – 0.95% 37
2025
Q3 		$60.7M Sell
2,019,000
-259,000
-11% -$7.77M 1.55% 22
2025
Q2 		$82.8M Buy
2,278,000
+253,500
+13% +$9.14M 2.5% 9
2025
Q1 		$73.3M Buy
2,024,500
+873,186
+76% +$36.3M 2.72% 10
2024
Q4 		$48.4M Hold
1,151,314
– – 1.65% 18
2024
Q3 		$64M Sell
1,151,314
-910,112
-44% -$46.4M 2.05% 12
2024
Q2 		$84.7M Buy
2,061,426
+384,615
+23% +$16.4M 3.11% 7
2024
Q1 		$78.3M Sell
1,676,811
-449,495
-21% -$21.2M 2.91% 7
2023
Q4 		$102M Buy
2,126,306
+1,446,847
+213% +$56.1M 4.6% 4
2023
Q3 		$24.2M Buy
679,459
+137,979
+25% +$5.47M 1.31% 25
2023
Q2 		$25M Sell
541,480
-75,000
-12% -$3.48M 1.34% 27
2023
Q1 		$24.7M Sell
616,480
-200,691
-25% -$8.61M 1.04% 35
2022
Q4 		$37.9M Buy
817,171
+728,231
+819% +$28.6M 1.59% 26
2022
Q3 		$3.68M Sell
88,940
-259,579
-74% -$13.3M 0.15% 62
2022
Q2 		$20.8M Sell
348,519
-176,581
-34% -$10.9M 0.79% 43
2022
Q1 		$38.1M Buy
525,100
+39,858
+8% +$2.77M 1.16% 33
2021
Q4 		$40.8M Buy
+485,242
New +$39.5M 0.79% 36

Other funds holding RARE

BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
AQR Capital Management
AQR Capital Management Greenwich, Connecticut $287B AUM 42.33% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
RI
RTW Investments New York $11.7B AUM 174.13% 1-Year Est. Return
Sands Capital Management
Sands Capital Management Arlington, Virginia $26.9B AUM 34.44% 1-Year Est. Return
SI
Sofinnova Investments Menlo Park, California $1.93B AUM 134.74% 1-Year Est. Return
Wellington Management Group
Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return
BG
Bellevue Group Kuesnacht, Switzerland $4.75B AUM 68.58% 1-Year Est. Return

Aaron Cowen's RARE Position: Q1 2026 in Review

Aaron Cowen sold out of Ultragenyx Pharmaceutical (RARE) in Q1 2026, closing a stake of 2,019,000 shares — an estimated $46.4M sold.

Aaron Cowen first reported a position in RARE in Q4 2021 and held it in 17 quarters. The position peaked at $102M in Q4 2023. 297 funds tracked by Wall St. Rank hold RARE as of Q1 2026.

  • Aaron Cowen reported no remaining Ultragenyx Pharmaceutical position as of Q1 2026 after selling out during the quarter.
  • Aaron Cowen sold 2,019,000 Ultragenyx Pharmaceutical shares in Q1 2026, an estimated $46.4M.
  • Aaron Cowen first reported a position in Ultragenyx Pharmaceutical in Q4 2021 and held it in 17 quarters.
  • Aaron Cowen's Ultragenyx Pharmaceutical position peaked at $102M in Q4 2023.
  • 297 funds tracked by Wall St. Rank held Ultragenyx Pharmaceutical as of Q1 2026.

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