Boundless Bio, Inc. (BOLD) Institutional Ownership

Ownership Summary

Boundless Bio, Inc. (NASDAQ:BOLD) currently has 34 active institutional owners and shareholders as of today (December 2025), that have filed 13F forms with the Securities Exchange Commission (SEC).

• Institutional ownership in Boundless Bio edged down to 37.8% in December 2025, compared to 41.7% in September 2025.
• Institutional share ownership changed by 12.89% QoQ, while the number of institutional owners saw a decrease of 39.29% YoY.
• During the quarter, 16 institutions bought more Boundless Bio shares, 9 sold shares, and 9 of the 34 total investors held their position steady.
• The aggregate institutional position in Boundless Bio now stands at 8.78Mn shares as of December 2025, after investors increased their holdings (up by 1.00Mn shares quarter on quarter which is down 4.18Mn shares year over year).
• FMR LLC's holding of 2.68Mn shares as of December 31, 2025 makes it the primary institutional investor in Boundless Bio, owning 11.56% of the stock.
• Among the most significant buyers of Boundless Bio during December 2025 were CITADEL ADVISORS LLC (477.49K), Stonepine Capital Management, LLC (296.62K), RBF Capital, LLC (200.00K), LANDSCAPE CAPITAL MANAGEMENT, L.L.C. (127.63K), RENAISSANCE TECHNOLOGIES LLC (117.84K).
• Leading sellers of Boundless Bio stock in December 2025 included FMR LLC (414.05K), MILLENNIUM MANAGEMENT LLC (28.68K), GEODE CAPITAL MANAGEMENT, LLC (8.17K), MORGAN STANLEY (2.50K), NORTHERN TRUST CORP (1.33K).
• The top 10 institutional holders of Boundless Bio for the quarter ending December 2025 included FMR LLC (2.68Mn), CITADEL ADVISORS LLC (1.35Mn), Stonepine Capital Management, LLC (710.07K), SECTORAL ASSET MANAGEMENT INC (678.57K), VANGUARD GROUP INC (662.76K), WELLINGTON MANAGEMENT GROUP LLP (556.23K), RBF Capital, LLC (400.00K), RENAISSANCE TECHNOLOGIES LLC (341.40K), Alyeska Investment Group, L.P. (300.00K), NORTHERN TRUST CORP (189.47K).