Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in RLYB held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | FMR LLC | 793K | $7.1M | -53.2% | 14.976% | 0.00% |
| 2 | VIKING GLOBAL INVESTORS LP | 524K | $4.7M | -87.5% | 9.897% | 0.01% |
| 3 | Cormorant Asset Management, LP | 400K | $3.6M | β | 7.550% | 0.18% |
| 4 | TPG GP A, LLC | 379K | $3.4M | -87.5% | 7.145% | 0.09% |
| 5 | BALYASNY ASSET MANAGEMENT LLC | 377K | $3.4M | β | 7.108% | 0.01% |
| 6 | Laurion Capital Management LP | 303K | $2.7M | β | 5.714% | 0.13% |
| 7 | Nantahala Capital Management, LLC | 301K | $2.7M | β | 5.674% | 0.14% |
| 8 | Pivotal bioVenture Partners Investment Advisor LLC | 301K | $2.7M | -87.5% | 5.673% | 0.96% |
| 9 | 5AM Venture Management, LLC | 292K | $2.6M | -92.0% | 5.507% | 0.73% |
| 10 | Almitas Capital LLC | 191K | $1.7M | -87.5% | 3.609% | 0.39% |
| 11 | RENAISSANCE TECHNOLOGIES LLC | 157K | $1.4M | -81.3% | 2.954% | 0.00% |
| 12 | JOHNSON & JOHNSON | 153K | $1.4M | -95.8% | 2.886% | 0.21% |
| 13 | VANGUARD CAPITAL MANAGEMENT LLC | 112K | $1.0M | β | 2.115% | 0.00% |
| 14 | AJU IB Investment Co., Ltd. | 94K | $846K | -87.5% | 1.781% | 2.77% |
| 15 | Mariner, LLC | 51K | $454K | -87.5% | 0.954% | 0.00% |
| 16 | GEODE CAPITAL MANAGEMENT, LLC | 35K | $318K | -85.7% | 0.669% | 0.00% |
| 17 | DELTEC ASSET MANAGEMENT LLC | 34K | $303K | β | 0.637% | 0.06% |
| 18 | Rangeley Capital, LLC | 30K | $270K | -24.7% | 0.569% | 0.29% |
| 19 | GTS SECURITIES LLC | 22K | $197K | β | 0.415% | 0.01% |
| 20 | ADAR1 Capital Management, LLC | 21K | $184K | β | 0.388% | 0.01% |
| 21 | CITADEL ADVISORS LLC | 20K | $178K | -92.2% | 0.375% | 0.00% |
| 22 | BlackRock, Inc. | 17K | $157K | -87.7% | 0.330% | 0.00% |
| 23 | VANGUARD FIDUCIARY TRUST CO | 14K | $122K | β | 0.256% | 0.00% |
| 24 | DIMENSIONAL FUND ADVISORS LP | 11K | $101K | β | 0.213% | 0.00% |
| 25 | XTX Topco Ltd | 11K | $101K | -88.5% | 0.212% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in RLYB β a direct measure of their conviction.
Filings activity in RLYB during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 37 | 20% | 49.49% | +25.02 pp | $42M | +102% |
| Q4 2025 | 46 | +4.5% | 24.47% | +7.82 pp | $21M | +47% |
| Q3 2025 | 44 | 10% | 16.65% | +4.25 pp | $14M | +34% |
| Q2 2025 | 49 | +2.1% | 12.40% | 12.32 pp | $10M | 50% |
| Q1 2025 | 48 | 2.0% | 24.72% | 11.21 pp | $21M | 31% |
| Q4 2024 | 49 | +0.0% | 35.93% | 7.19 pp | $30M | 17% |
| Q3 2024 | 49 | 26% | 43.12% | 6.93 pp | $36M | 14% |
| Q2 2024 | 66 | β | 50.05% | β | $42M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying RLYB stock.
Based on Q1 2026 13F filings, institutional ownership of Rallybio Corporation stands at 49.5%, held across 37 reporting institutions.
FMR LLC is the largest reported institutional holder of RLYB, with approximately 793,451 shares worth $0.01B as of Q1 2026.
Yes β 3 widely-followed marquee investors appear among the top 25 institutional holders of RLYB, including VIKING GLOBAL INVESTORS LP, RENAISSANCE TECHNOLOGIES LLC, CITADEL ADVISORS LLC.
Our composite Smart Money Score for RLYB is 63 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
13 institutions opened new positions in RLYB during Q1 2026, while 22 fully exited. 21 added to existing positions and 3 trimmed.
RLYB institutional ownership rose by 25.02 percentage points quarter-over-quarter, with a net change of -9 holders.
The top 10 institutions account for 82.9% of all reported 13F value in RLYB, and the top 25 account for 99.7%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Rallybio Corporation (RLYB) Institutional Ownership