
Founded in 2009 by Marc Andreessen and Ben Horowitz, a16z is the world's largest venture capital firm by assets under management. The firm operates a distinctive platform model, providing portfolio companies with dedicated support across recruiting, marketing, and business development. In January 2026 it closed over $15 billion in new funds, representing 18% of all US venture capital allocated in 2025. Since 2020, a16z has backed 32 unicorns, more than any other venture firm. Notable investments include Facebook, Airbnb, Coinbase, OpenAI, Stripe, and GitHub.