Rallybio
RLYB
45 hedge funds and large institutions have $14.1M invested in Rallybio in 2025 Q3 according to their latest regulatory filings, with 6 funds opening new positions, 7 increasing their positions, 12 reducing their positions, and 9 closing their positions.
34% more capital invested
Capital invested by funds: $10.5M → $14.1M (+$3.6M)
25% more funds holding in top 10
Funds holding in top 10: 4 → 5 (+1)
0.91% less ownership
Funds ownership: 9.37% → 8.46% (-0.91%)
6% less funds holding
Funds holding: 48 → 45 (-3)
33% less first-time investments, than exits
New positions opened: 6 | Existing positions closed: 9
42% less repeat investments, than reductions
Existing positions increased: 7 | Existing positions reduced: 12
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Citadel Advisors
Miami,
Florida
|
+$196K |
| 2 |
Renaissance Technologies
New York
|
+$121K |
| 3 |
Susquehanna International Group
Bala Cynwyd,
Pennsylvania
|
+$59.4K |
| 4 |
Vanguard Group
Malvern,
Pennsylvania
|
+$47.1K |
| 5 |
RC
Rangeley Capital
New Canaan,
Connecticut
|
+$43.6K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Aberdeen Group
Edinburgh,
United Kingdom
|
-$539K |
| 2 |
CPX
Canaan Partners XI
Menlo Park,
California
|
-$258K |
| 3 |
LCM
Laurion Capital Management
New York
|
-$249K |
| 4 |
AC
Almitas Capital
Santa Monica,
California
|
-$146K |
| 5 |
Fidelity Investments
Boston,
Massachusetts
|
-$92.4K |
| Name | Holding | Trade Value |
Shares Change |
Change in Stake |
|
|---|---|---|---|---|---|
51
Jane Street
New York
| – | -$3.97K | -1,468 | Closed |
|
52
HSBC Holdings
London,
United Kingdom
| – | -$3.5K | -1,315 | Closed |
|
53
Federated Hermes
Pittsburgh,
Pennsylvania
| – | -$747 | -276 | Closed |
|
54
Raymond James Financial
St Petersburg,
Florida
| – | -$288 | -106 | Closed |
|
RLYB Hedge Fund Activity: Q3 2025 in Review
45 of the 7,625 institutional investors tracked by Wall St. Rank reported a position in Rallybio (RLYB) for Q3 2025, worth a combined $14.1M — up 34% from $10.5M a quarter earlier.
Sellers outnumbered buyers: 9 funds closed out of RLYB and 6 opened new positions — a net loss of 3 holders — while 12 trimmed existing stakes and 7 added.
The largest buyer was Citadel Advisors, adding an estimated $196K. The largest seller was Aberdeen Group, exiting entirely with an estimated $539K sold.
- 45 institutional investors held Rallybio (RLYB) as of Q3 2025, down from 48 in Q2 2025.
- Funds reported $14.1M of Rallybio stock for Q3 2025, up 34% quarter-over-quarter.
- 6 funds opened new Rallybio positions in Q3 2025 and 9 closed out, a net change of -3 holders.
- The largest Rallybio buyer in Q3 2025 was Citadel Advisors, an estimated $196K added.
- The largest Rallybio seller in Q3 2025 was Aberdeen Group, an estimated $539K sold.
Based on aggregated 13F filings for Q3 2025.