SOSV is a global venture capital firm founded in 1995 by Sean O'Sullivan. It is recognized as the world's most active deep tech, pre-seed venture capital firm, providing initial funding and extensive support to startups. The firm operates renowned accelerator programs: HAX, which focuses on hard tech, industrial decarbonization, automation, robotics, and human health, and IndieBio (now SOSV NY & SOSV SF), which specializes in life sciences for human and planetary health. SOSV provides state-of-the-art labs, expert mentorship, and a vast network to accelerate product development, customer acquisition, and scaling. As of 2026, SOSV manages $1.5 billion in assets and has invested in over 800 active portfolio companies, which collectively have raised billions in follow-on funding.