Venture firm Apple Tree Partners filed for Chapter 11 in the face of a funding dispute with major backers, aiming to restructure and ensure continued financing for its portfolio companies. Court filings and reporting indicate litigation with funders tied to a Russian‑linked investor group and a prior Delaware Chancery ruling ordering funding disbursement. ATP said bankruptcy will protect ongoing research programs across oncology, neurology and infectious disease startups; counterparties disputed management and alleged mismanagement. The restructuring underscores strain in startup financing and highlights systemic risks for early‑stage biotech reliant on single large backers.