RLYB
Rallybio Corporation
NASDAQ · USHealthcareBiotechnology
$16.47+0.31%
Price as of Jul 20, 2026
RLYB ownership
Rallybio Corporation ownership & insider activity
Latest available institutional positioning and SEC Form 4 insider transactions, coalesced at the company entity level when listings share coverage.
Insider Activity
Sentiment
100/100
Buys (3m)
14
Sells (3m)
0
Net (3m)
$4.2M
Insiders buying
Insider trades by month Buys Sells
May
Jun
Nov
Mar
Feb
May
Context3-month price +94.2%Institutions reducing (13F)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Jul 10, 2026 | Boudreau Helen Mdirector | Option | 3,562 | $2.38 |
| May 20, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 200 | $13.80 |
| May 20, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 6,009 | $13.98 |
| May 20, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 10,000 | $13.98 |
| May 15, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 200 | $13.95 |
| May 15, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 4,081 | $13.80 |
| May 15, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 75,178 | $14.00 |
| May 15, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 100 | $13.80 |
| May 13, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 19,900 | $14.00 |
| May 13, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 5,100 | $14.00 |
| May 13, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 25,000 | $14.00 |
| May 13, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 800 | $13.83 |
| May 6, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 3,900 | $13.90 |
| May 6, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 35,101 | $14.00 |
| May 6, 2026 | ADAR1 Capital Management, LLC10 percent owner | Buy | 116,904 | $13.97 |
| Feb 23, 2026 | Lieber Jonathan Iofficer: Chief Financial Officer | Grant | 2,500 | — |
| Feb 23, 2026 | Lieber Jonathan Iofficer: Chief Financial Officer | Sell | 789 | $5.06 |
| Feb 20, 2026 | HUNT RONALDdirector | Grant | 14,305 | $4.45 |
| Feb 20, 2026 | MACKAY MARTINdirector | Grant | 18,055 | $4.45 |
| May 15, 2025 | Soteropoulos Pauladirector | Grant | 28,500 | $0.30 |
| May 15, 2025 | Hopfner Robert Lornedirector | Grant | 28,500 | $0.30 |
| May 15, 2025 | Nash Christine Adirector | Grant | 28,500 | $0.30 |
| May 15, 2025 | HUNT RONALDdirector | Grant | 28,500 | $0.30 |
| May 15, 2025 | Boudreau Helen Mdirector | Grant | 28,500 | $0.30 |
| May 15, 2025 | MACKAY MARTINdirector | Grant | 28,500 | $0.30 |
| May 15, 2025 | Liu Huidirector | Grant | 28,500 | $0.30 |
| May 15, 2025 | Chung Wendydirector | Grant | 28,500 | $0.30 |
| Feb 19, 2025 | Ryder Stevenofficer: Chief Medical Officer | Grant | 180,000 | $0.76 |
| Feb 19, 2025 | Lieber Jonathan Iofficer: Chief Financial Officer | Grant | 180,000 | $0.76 |
| Feb 19, 2025 | Uden Stephendirector, officer: Chief Executive Officer | Grant | 453,700 | $0.76 |
Source: RLYB SEC Form 4 filings, latest Jul 10, 2026. For informational purposes only — not investment advice.
Institutional activity (13F)
How institutions changed their RLYB positions over the last 6 months (SEC Form 13F).
Increased
10
New positions
15
Reduced
36
Sold out
23
Largest moves
| Institution | Action | Shares | Filed |
|---|---|---|---|
| VIKING GLOBAL INVESTORS LP | Unchanged | 4.2M | Feb 17, 2026 |
| JOHNSON & JOHNSON | Unchanged | 3.6M | Mar 18, 2026 |
| 5AM VENTURE MANAGEMENT, LLC | Unchanged | 3.6M | Feb 17, 2026 |
| TPG GP A, LLC | Unchanged | 3.0M | Feb 13, 2026 |
| PIVOTAL BIOVENTURE PARTNERS INVESTMENT ADVISOR LLC | Unchanged | 2.4M | Feb 13, 2026 |
| FMR LLC | Unchanged | 1.7M | Feb 17, 2026 |
| ALMITAS CAPITAL LLC | Reduced | 1.5M | Feb 17, 2026 |
| VANGUARD GROUP INC | Increased | 1.0M | Jan 29, 2026 |
| RENAISSANCE TECHNOLOGIES LLC | Increased | 836K | Feb 12, 2026 |
| FMR LLC | Reduced | 793K | May 15, 2026 |
| AJU IB INVESTMENT CO., LTD. | Unchanged | 755K | Feb 10, 2026 |
| VIKING GLOBAL INVESTORS LP | Reduced | 524K | May 15, 2026 |
| CANAAN PARTNERS XI LLC | Unchanged | 450K | Feb 13, 2026 |
| MARINER, LLC | Unchanged | 405K | Feb 13, 2026 |
| CORMORANT ASSET MANAGEMENT, LP | New Position | 400K | May 15, 2026 |
Source: SEC Form 13F filings. For informational purposes only — not investment advice.