RALLYBIO CORP RLYB
COM · Common Stock · CUSIP 75120L209
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersNew Haven, CT
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Implied quarter-end price ≈ $6.70.
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q4 2025 | 1 |
| Q1 2026 | 38 |
| Q2 2026 | 37 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2026 | 35 | 1 |
| Q2 2026 | 19 | 16 |
Biggest buyers
| CITADEL ADVISORS LLC | Added | +7.7m |
| ADAR1 Capital Management, LLC | Added | +905.8k |
| Nantahala Capital Management, LLC | Added | +76.2k |
| Rangeley Capital, LLC | Added | +74.7k |
| VANGUARD CAPITAL MANAGEMENT LLC | Added | +60.5k |
| JANE STREET GROUP, LLC | New | +47.4k |
| RENAISSANCE TECHNOLOGIES LLC | Added | +43.4k |
| HRT FINANCIAL LP | New | +25.7k |
| TWO SIGMA INVESTMENTS, LP | New | +16.6k |
| STATE STREET CORP | New | +13.0k |
Biggest sellers
| Cormorant Asset Management, LP | Sold out | -400.0k |
| Balyasny Asset Management L.P. | Sold out | -376.6k |
| Laurion Capital Management LP | Sold out | -302.8k |
| 5AM Venture Management, LLC | Sold out | -291.8k |
| JOHNSON & JOHNSON | Sold out | -152.9k |
| AJU IB Investment Co., Ltd. | Sold out | -94.3k |
| Almitas Capital LLC | Reduced | -70.5k |
| DELTEC ASSET MANAGEMENT LLC | Sold out | -33.8k |
| GTS SECURITIES LLC | Sold out | -22.0k |
| ACADIAN ASSET MANAGEMENT LLC | Sold out | -10.4k |
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| ADAR1 Capital Management, LLC 13G · institution new · filed 2026-06-05 | 17.5% |
| FMR LLC 13G · passive investor +4.4 pts · filed 2026-08-06 | 15.0% |
| VIKING GLOBAL INVESTORS LP 13G · passive investor filed 2026-05-15 | 10.0% |
Fell to 5% or below in the last year: BALYASNY ASSET MANAGEMENT L.P. (0.0%, 2026-08-14), Nantahala Capital Management, LLC (3.6%, 2026-08-14), Cormorant Asset Management, LP (0.0%, 2026-08-14), Laurion Capital Management LP (0.0%, 2026-08-04), 5AM Ventures V, L.P. (0.0%, 2026-05-06), JOHNSON & JOHNSON (2.9%, 2026-04-13)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 0 | — | 1 | $4.0k | — |
| Q2 2026 | 0 | — | 0 | — | — |
| Q3 2026 | 0 | — | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-05-19 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $142.6k10.2k shares |
| 2026-05-18 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $84.0k6.0k shares |
| 2026-05-15 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $4.2k300 shares |
| 2026-05-13 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $1.1m79.3k shares |
| 2026-05-12 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $11.1k800 shares |
| 2026-05-11 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $700.0k50.0k shares |
| 2026-05-05 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $491.4k35.1k shares |
| 2026-05-04 | Schneeberger Daniel +1 10% owner · See Footnote | Bought | $1.7m120.8k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| CITADEL ADVISORS LLC 0.01% of their portfolio | 7.7m $12.7m | Added +7.7m |
| ADAR1 Capital Management, LLC 0.70% of their portfolio | 926.4k $14.8m | Added +905.8k |
| FMR LLC 0.00% of their portfolio | 794.7k $12.7m | Added +1.3k |
| VIKING GLOBAL INVESTORS LP 0.02% of their portfolio | 524.3k $8.4m | Unchanged |
| TPG GP A, LLC 0.12% of their portfolio | 378.6k $6.1m | Unchanged |
| Nantahala Capital Management, LLC 0.18% of their portfolio | 376.8k $6.0m | Added +76.2k |
| Pivotal bioVenture Partners Investment Advisor LLC 1.56% of their portfolio | 300.6k $4.8m | Unchanged |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 199.9k $3.2m | Added +43.4k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 172.5k $2.8m | Added +60.5k |
| Almitas Capital LLC 0.46% of their portfolio | 120.7k $1.9m | Reduced -70.5k |
| Rangeley Capital, LLC 1.56% of their portfolio | 104.8k $1.7m | Added +74.7k |
| Mariner, LLC 0.00% of their portfolio | 50.6k $809.1k | Unchanged |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 47.4k $758.8k | New |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 32.0k $512.9k | Reduced -3.4k |
| BlackRock, Inc. 0.00% of their portfolio | 30.3k $485.3k | Added +12.8k |
| HRT FINANCIAL LP 0.00% of their portfolio | 25.7k $410.0k | New |
| XTX Topco Ltd 0.00% of their portfolio | 21.5k $344.0k | Added +10.3k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 16.8k $269.1k | Added +3.3k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 16.6k $265.9k | New |
| STATE STREET CORP 0.00% of their portfolio | 13.0k $207.9k | New |
| Quadrature Capital Ltd 0.00% of their portfolio | 13.0k $207.9k | New |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 11.3k $180.5k | Unchanged |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 1.4k $23.1k | Unchanged |
| Hartford Financial Management Inc. 0.00% of their portfolio | 812 $13.0k | Unchanged |
| SBI Securities Co., Ltd. 0.00% of their portfolio | 506 $8.1k | Reduced -18 |
| Caitong International Asset Management Co., Ltd 0.00% of their portfolio | 434 $6.9k | New |
| UBS Group AG 0.00% of their portfolio | 146 $2.3k | Reduced -7.8k |
| Truvestments Capital LLC 0.00% of their portfolio | 129 $2.1k | New |
| MORGAN STANLEY 0.00% of their portfolio | 125 $2.0k | Reduced -1 |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 120 $1.9k | Unchanged |
| Fortitude Family Office, LLC 0.00% of their portfolio | 53 $848 | Unchanged |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 37 $592 | Unchanged |
| EverSource Wealth Advisors, LLC 0.00% of their portfolio | 31 $496 | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 9 $145 | Reduced -2.5k |
| Allworth Financial LP 0.00% of their portfolio | 6 $96 | Unchanged |
| BARCLAYS PLC 0.00% of their portfolio | 3 $48 | New |
| DANSKE BANK A/S 0.00% of their portfolio | 1 $16 | Unchanged |