JB
GBIO

Julian Baker’s Generation Bio GBIO Stock Holding History

Julian Baker’s Portfolio GBIO Stock Details GBIO Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2025
Q4 		– Sell
-194,493
Closed -$1.19M – 91
2025
Q3 		$1.19M Sell
194,493
-2
-0% -$10 0.01% 84
2025
Q2 		$623K Hold
194,495
– – 0.01% 84
2025
Q1 		$788K Hold
194,495
– – 0.01% 82
2024
Q4 		$2.06M Hold
194,495
– – 0.02% 84
2024
Q3 		$4.8M Buy
194,495
+73,799
+61% +$1.95M 0.05% 69
2024
Q2 		$3.4M Buy
120,696
+83,574
+225% +$2.72M 0.04% 75
2024
Q1 		$1.51M Buy
+37,122
New +$874K 0.02% 77

Other funds holding GBIO

AVLSA
Atlas Venture Life Science Advisors Cambridge, Massachusetts $881M AUM 160.77% 1-Year Est. Return
SCP
SymBiosis Capital Partners Bentonville, Arkansas $52.8M AUM
OM
Opaleye Management Boston, Massachusetts $1.1B AUM 197.64% 1-Year Est. Return
Renaissance Technologies
Renaissance Technologies New York $72.6B AUM 54.88% 1-Year Est. Return
Vanguard Group
Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return
T. Rowe Price Associates
T. Rowe Price Associates Baltimore, Maryland $999B AUM 46.22% 1-Year Est. Return
SL
Siren LLC Greenwich, Connecticut $4.94B AUM 244.43% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $786B AUM 40.34% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return
Marshall Wace
Marshall Wace London, United Kingdom $127B AUM 46.06% 1-Year Est. Return

Julian Baker's GBIO Position: Q4 2025 in Review

Julian Baker sold out of Generation Bio (GBIO) in Q4 2025, closing a stake of 194,493 shares — an estimated $1.19M sold.

Julian Baker first reported a position in GBIO in Q1 2024 and held it in 7 quarters. The position peaked at $4.8M in Q3 2024. 48 funds tracked by Wall St. Rank hold GBIO as of Q4 2025.

  • Julian Baker reported no remaining Generation Bio position as of Q4 2025 after selling out during the quarter.
  • Julian Baker sold 194,493 Generation Bio shares in Q4 2025, an estimated $1.19M.
  • Julian Baker first reported a position in Generation Bio in Q1 2024 and held it in 7 quarters.
  • Julian Baker's Generation Bio position peaked at $4.8M in Q3 2024.
  • 48 funds tracked by Wall St. Rank held Generation Bio as of Q4 2025.

Based on Baker Bros. Advisors's 13F filing for Q4 2025, filed 17 Feb 2026.