Rallybio Corp (RLYB) Institutional Ownership

Ownership Summary

Rallybio Corp (NASDAQ:RLYB) has 45 institutional investors that have filed 13F reports for the period ending December 2025.

• Their combined ownership stood at 55.3% of outstanding shares in December 2025, down from 66.1% in September 2025.
• They decreased total shares held in Rallybio by -5.82% from the prior quarter, while the number of investors in RLYB decreased 10.0% year over year.
• Of these 45 funds, 10 grew their exposure to Rallybio, 12 cut back, and 23 maintained positions.
• Institutional investors collectively held 3.12Mn shares in Rallybio as of December 2025, down by 192.63K shares quarter on quarter, and down 942.96K shares year over year.
• As of December 31, 2025, the biggest holder of Rallybio is VIKING GLOBAL INVESTORS LP at 524.35K shares, representing 9.31% of shares outstanding.
• Leading buyers of Rallybio shares for the quarter ending December 2025 were RENAISSANCE TECHNOLOGIES LLC (15.11K), XTX Topco Ltd (12.16K), GSA CAPITAL PARTNERS LLP (2.41K), TWO SIGMA ADVISERS, LP (2.41K), VANGUARD GROUP INC (2.08K).
• The biggest sellers of Rallybio for the quarter ending December 2025 included Almitas Capital LLC (193.48K), CITADEL ADVISORS LLC (23.11K), Rangeley Capital, LLC (5.38K), SUSQUEHANNA INTERNATIONAL GROUP, LLP (4.45K), Virtu Financial LLC (1.52K).
• According to Business Quant data, leading holders of RLYB for December 2025 are VIKING GLOBAL INVESTORS LP (524.35K), Johnson & Johnson (454.55K), 5AM Venture Management, LLC (453.84K), TPG GP A, LLC (378.55K), Pivotal bioVenture Partners Investment Advisor LLC (300.58K), FMR LLC (211.8K), Almitas Capital LLC (191.21K), VANGUARD GROUP INC (127.03K), RENAISSANCE TECHNOLOGIES LLC (104.46K), AJU IB Investment Co., Ltd. (94.33K).