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GBIO

Generation Bio
GBIO

Delisted

GBIO was delisted on the 6th of February, 2026.

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88 hedge funds and large institutions have $1.27B invested in Generation Bio in 2021 Q1 according to their latest regulatory filings, with 30 funds opening new positions, 44 increasing their positions, 8 reducing their positions, and 9 closing their positions.

New
Increased
Maintained
Reduced
Closed

450% more repeat investments, than reductions

Existing positions increased: 44 | Existing positions reduced: 8

233% more first-time investments, than exits

New positions opened: 30 | Existing positions closed: 9

40% more capital invested

Capital invested by funds: $906M → $1.27B (+$361M)

29% more funds holding

Funds holding: 68 → 88 (+20)

1.02% more ownership

Funds ownership: 6.87% → 7.9% (+1%)

75% less funds holding in top 10

Funds holding in top 10: 4 → 1 (-3)

100% less call options, than puts

Call options by funds: $0 | Put options by funds: $6.11M

Holders
88
Holders Change
+20
Holders Change %
+29.41%
% of All Funds
1.54%
Holding in Top 10
1
Holding in Top 10 Change
-3
Holding in Top 10 Change %
-75%
% of All Funds
0.02%
New
30
Increased
44
Reduced
8
Closed
9
Calls
–
Puts
$6.11M
Net Calls
-$6.11M
Net Calls Change
-$6.11M

Top Buyers

Rank Fund Capital Flow
1
T. Rowe Price Associates
T. Rowe Price Associates
Maryland
+$66.9M
2
Vanguard Group
Vanguard Group
Pennsylvania
+$64.3M
3
State Street
State Street
Massachusetts
+$50.5M
4
BlackRock
BlackRock
New York
+$50.5M
5
CG
Carmignac Gestion
France
+$49.2M

Top Sellers

Rank Fund Capital Flow
1
Wellington Management Group
Wellington Management Group
Massachusetts
-$55.5M
2
FCMI
Foresite Capital Management IV
California
-$24.3M
3
TOCUITCONY
Trustees of Columbia University in the City of New York
New York
-$8.87M
4
DM
Deerfield Management
New York
-$2.03M
5
Millennium Management
Millennium Management
New York
-$971K
Name Holding Trade Value Shares
Change 		Change in
Stake
American Century Companies
26
American Century Companies
Missouri
$4.05M +$722K +2,257 +19%
D.E. Shaw & Co
27
D.E. Shaw & Co
New York
$3.81M +$3.77M +11,771 +720%
Voloridge Investment Management
28
Voloridge Investment Management
Florida
$3.64M +$4.09M +12,791 New
LCM
29
Laurion Capital Management
New York
$3.56M +$4M +12,500 New
Citigroup
30
Citigroup
New York
$3.42M +$3.73M +11,640 +2,947%
N
31
Nuveen
North Carolina
$3.36M +$2.29M +7,151 +153%
Rafferty Asset Management
32
Rafferty Asset Management
New York
$2.73M +$3.07M +9,588 New
Swiss National Bank
33
Swiss National Bank
Switzerland
$1.99M +$1.4M +4,380 +167%
PMAM
34
Penn Mutual Asset Management
Pennsylvania
$1.94M +$881K +2,752 +68%
California State Teachers Retirement System (CalSTRS)
35
California State Teachers Retirement System (CalSTRS)
California
$1.73M +$1.35M +4,219 +227%
Simplex Trading
36
Simplex Trading
Illinois
$1.59M +$1.79M +5,603 New
State of Wisconsin Investment Board
37
State of Wisconsin Investment Board
Wisconsin
$1.54M +$1.18M +3,700 +214%
AllianceBernstein
38
AllianceBernstein
Tennessee
$1.31M +$1.47M +4,601 New
RhumbLine Advisers
39
RhumbLine Advisers
Massachusetts
$1.2M +$912K +2,850 +208%
Susquehanna International Group
40
Susquehanna International Group
Pennsylvania
$1.16M +$1.3M +4,070 New
Citadel Advisors
41
Citadel Advisors
Florida
$1.04M +$1.17M +3,648 New
Los Angeles Capital Management
42
Los Angeles Capital Management
California
$933K +$1.05M +3,279 New
UBS Group
43
UBS Group
Switzerland
$774K +$870K +2,719 New
CS
44
Credit Suisse
Switzerland
$641K +$48K +150 +7%
California Public Employees Retirement System
45
California Public Employees Retirement System
California
$635K -$65.9K -206 -8%
New York State Common Retirement Fund
46
New York State Common Retirement Fund
New York
$632K +$352K +1,100 +98%
Manulife (Manufacturers Life Insurance)
47
Manulife (Manufacturers Life Insurance)
Ontario, Canada
$627K +$475K +1,484 +207%
SAM
48
Sectoral Asset Management
Quebec, Canada
$613K +$689K +2,152 New
Ameriprise
49
Ameriprise
Minnesota
$584K -$137K -429 -17%
SFI
50
Susquehanna Fundamental Investments
Pennsylvania
$555K – – –
1
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GBIO Hedge Fund Activity: Q1 2021 in Review

88 of the 5,696 institutional investors tracked by Wall St. Rank reported a position in Generation Bio (GBIO) for Q1 2021, worth a combined $1.27B — up 40% from $906M a quarter earlier.

Buyers outnumbered sellers: 30 funds opened new GBIO positions and 9 closed out — a net gain of 21 holders — while 44 added to existing stakes and 8 trimmed.

The largest buyer was T. Rowe Price Associates, adding an estimated $66.9M. The largest seller was Wellington Management Group, cutting an estimated $55.5M.

  • 88 institutional investors held Generation Bio (GBIO) as of Q1 2021, up from 68 in Q4 2020.
  • Funds reported $1.27B of Generation Bio stock for Q1 2021, up 40% quarter-over-quarter.
  • 30 funds opened new Generation Bio positions in Q1 2021 and 9 closed out, a net change of +21 holders.
  • The largest Generation Bio buyer in Q1 2021 was T. Rowe Price Associates, an estimated $66.9M added.
  • The largest Generation Bio seller in Q1 2021 was Wellington Management Group, an estimated $55.5M sold.

Based on aggregated 13F filings for Q1 2021.