RallybioRLYB
13F holders, Q1 2026 (March 31)At the end of Q1 2026, 38 institutions reported holding Rallybio Corp. (RLYB) in their 13F filings, up 37 from Q4 2025. 10 opened new positions and 1 sold out. The largest holders were FMR LLC ($7.1M), Viking Global Investors ($4.7M) and Cormorant Asset Management, LP ($3.6M). 3 famous investors held it, including Andreas Halvorsen (0.0% of Viking Global Investors's portfolio), Jim Simons / Peter Brown (0.0% of Renaissance Technologies's portfolio) and Ken Griffin (0.0% of Citadel Advisors's portfolio).
- Company
- Rallybio Corp.
- CUSIP
- 75120L209
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q4 2025 → Q1 2026
| Institutions | Total Value | |
|---|---|---|
| New Positions | 10 | $13.2M |
| Exits | 1 | $7K |
All 13F filers, Q4 2025 → Q1 2026: 2,141,042 shares bought and 487,165 shares sold, net +1,653,876 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 38 holders
| FMR LLC | 0.00% | Add +274.6% | 793,451 | $7.1M |
| Viking Global Investors | 0.01% | No change | 524,347 | $4.7M |
| Cormorant Asset Management, LP | 0.18% | New | 400,000 | $3.6M |
| TPG GP A, LLC | 0.10% | No change | 378,551 | $3.4M |
| Balyasny Asset Management L.P. | 0.01% | New | 376,573 | $3.4M |
| Laurion Capital Management LP | 0.27% | New | 302,756 | $2.7M |
| Nantahala Capital Management, LLC | 0.17% | New | 300,635 | $2.7M |
| Pivotal bioVenture Partners Investment Advisor LLC | 0.96% | No change | 300,579 | $2.7M |
| 5AM Venture Management, LLC | 0.73% | Reduce -35.7% | 291,788 | $2.6M |
| Almitas Capital LLC | 0.39% | No change | 191,206 | $1.7M |
| Renaissance Technologies | 0.00% | Add +49.8% | 156,527 | $1.4M |
| Johnson & Johnson | 0.21% | Reduce -66.4% | 152,901 | $1.4M |
| Vanguard Capital Management LLC | 0.00% | — | 112,040 | $1.0M |
| AJU IB Investment Co., Ltd. | 2.77% | No change | 94,334 | $846K |
| Mariner, LLC | 0.00% | No change | 50,566 | $454K |
| Geode Capital Management, LLC | 0.00% | Add +14.3% | 35,425 | $318K |
| Deltec Asset Management LLC | 0.06% | New | 33,750 | $303K |
| Rangeley Capital, LLC | 0.29% | Add +502.6% | 30,130 | $270K |
| GTS Securities LLC | 0.01% | New | 22,016 | $197K |
| ADAR1 Capital Management, LLC | 0.01% | New | 20,535 | $184K |
| Citadel Advisors | 0.00% | Reduce -37.3% | 19,886 | $178K |
| BlackRock, Inc. | 0.00% | Reduce -1.3% | 17,486 | $157K |
| Vanguard Fiduciary Trust Co. | 0.00% | — | 13,547 | $122K |
| Dimensional Fund Advisors LP | 0.00% | New | 11,280 | $101K |
| XTX Topco Ltd | 0.00% | Reduce -7.7% | 11,226 | $101K |
| Acadian Asset Management LLC | 0.00% | No change | 10,433 | $92K |
| UBS Group AG | 0.00% | Add +1283.3% | 7,914 | $71K |
| JPMorgan Chase & Co. | 0.00% | Add +24261.0% | 2,497 | $20K |
| Vanguard Global Advisers, LLC | 0.00% | — | 1,442 | $13K |
| Tower Research Capital LLC (TRC) | 0.00% | Add +60.4% | 907 | $8K |
| Hartford Financial Management Inc. | 0.00% | No change | 812 | $7K |
| SBI Securities Co., Ltd. | 0.00% | Reduce -1.3% | 524 | $5K |
| Morgan Stanley | 0.00% | Reduce -78.3% | 126 | $1K |
| BNP Paribas Financial Markets | 0.00% | Reduce -2.0% | 120 | $1K |
| Fortitude Family Office, LLC | 0.00% | New | 53 | $475 |
| Wells Fargo & Company | 0.00% | Reduce -1.3% | 37 | $332 |
| Allworth Financial LP | 0.00% | Reduce -4.0% | 6 | $54 |
| Danske Bank A/S | 0.00% | New | 1 | $9 |
"% of holder's portfolio" is RLYB's weight in each manager's 13F, not the share of Rallybio Corp. the manager owns.