Andreessen Horowitz
Silicon Valley venture firm with $100B+ AUM; co-led ElevenLabs' Series C and backed Improbable
- Venture capital
- Type
- Venture capital
- Based in
- Outside the UK
- Stages
- Seed, Series A, Series B+, Growth
- Sector focus
- Sector-agnostic
- Fund size
- Over $100B in assets under management (as at 30 April 2026)
- Founded
- 2009
- Website
- a16z.com
Andreessen Horowitz, known as a16z, is a Silicon Valley venture capital firm founded in 2009 by Marc Andreessen and Ben Horowitz. It manages more than $100B across multiple funds and backs technology companies from seed through venture and growth stages. Its investing teams cover AI, bio and healthcare, consumer, crypto, enterprise, fintech, games, infrastructure and American dynamism. The firm is based in California but invests internationally, including in the UK, where it co-led voice AI company ElevenLabs' Series C in 2025 and participated in Improbable's $502M Series B in 2017. Typical cheques range widely with stage and fund.
Team
- Marc Andreessen, Co-founder and General Partner X
- Ben Horowitz, Co-founder and General Partner LinkedIn · X
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