Boundless Bio BOLD Institutional Ownership

Ownership Summary

Boundless Bio, Inc. (NASDAQ:BOLD) appears in 36 institutional 13F filings for the quarter ending March 2026.

• Collectively, these holders controlled 38.8% of Boundless Bio's outstanding shares in March 2026, down from 39.4% in December 2025.
• They increased total shares held in Boundless Bio by 10.0% from the prior quarter, while the number of investors in BOLD decreased 34.55% year over year.
• During the quarter, 14 of these 36 funds increased positions in BOLD, 10 reduced exposure, and 12 held steady.
• The aggregate institutional position in Boundless Bio amounted to 8.69Mn shares as of March 2026, up by 789.88K shares quarter on quarter, and down 8.7Mn shares year over year.
• As of March 31, 2026, FMR LLC held the largest stake in Boundless Bio with 2.7Mn shares, accounting for 12.03% of total shares outstanding.
• The largest buyers of Boundless Bio for the quarter ending March 2026 were VANGUARD CAPITAL MANAGEMENT LLC (597.19K), Ensign Peak Advisors, Inc (187.5K), VANGUARD FIDUCIARY TRUST CO (65.14K), RENAISSANCE TECHNOLOGIES LLC (57.6K), GSA CAPITAL PARTNERS LLP (34.35K).
• The biggest sellers of Boundless Bio for the quarter ending March 2026 included Stonepine Capital Management, LLC (112.39K), LANDSCAPE CAPITAL MANAGEMENT, L.L.C. (41.83K), MILLENNIUM MANAGEMENT LLC (35.54K), Citigroup Inc (16.24K), CITADEL ADVISORS LLC (11.77K).
• Business Quant data shows the 10 biggest positions in Boundless Bio as of March 2026 are held by FMR LLC (2.7Mn), CITADEL ADVISORS LLC (1.34Mn), SECTORAL ASSET MANAGEMENT INC (678.57K), Stonepine Capital Management, LLC (597.68K), VANGUARD CAPITAL MANAGEMENT LLC (597.19K), WELLINGTON MANAGEMENT GROUP LLP (556.23K), RBF Capital, LLC (400.0K), RENAISSANCE TECHNOLOGIES LLC (399.0K), Alyeska Investment Group, L.P. (300.0K), Ensign Peak Advisors, Inc (187.5K).