Michael Castor

Michael Castor is the Founder, Portfolio Manager, and Managing Director of Sio Capital Management, LLC, a New York-based investment management firm specializing in healthcare. Since founding Sio in 2006, he has overseen all investment strategy and portfolio management, with a core focus on global equity market-neutral strategies targeting healthcare and biotechnology sectors.

Dr. Castor’s investment approach leverages his deep sector expertise to uncover opportunities across the healthcare landscape, including pharmaceuticals, biotechnology, medical devices, and healthcare services. He is known for rigorous financial modeling and fundamental research, utilizing both long and short strategies to navigate complex market and regulatory environments.

Before establishing Sio, Dr. Castor served as a healthcare analyst at AllianceBernstein and previously focused on biotechnology and healthcare equity offerings at JP Morgan. He holds an MD from The Ohio State University College of Medicine (summa cum laude) and a BSE in Biomedical Engineering from Tulane University (summa cum laude with honors), and he completed postgraduate medical training in surgery and otolaryngology, integrating clinical insights into his investment process.