Andreessen Horowitz (a16z) is a venture capital firm founded in 2009 by Marc Andreessen and Ben Horowitz. The firm backs bold entrepreneurs building the future across consumer technology, enterprise software, fintech, crypto, bio/health, games, and American Dynamism. With offices in Menlo Park, San Francisco, and internationally, a16z provides founders with access to an extensive network of executives, engineers, and domain experts through its dedicated operational teams.
Two technical founders who had built and sold Opsware to HP for $1.6B launched Andreessen Horowitz with a vision to support founders with more than just capital. The firm provides portfolio companies with dedicated operational support teams.
Marc AndreessenCo-founder & General PartnerCo-founder of Netscape and creator of the Mosaic browser. Co-founder of Opsware, sold to HP for $1.6B. Author of "Why Software Is Eating the World."LinkedIn ↗
Ben HorowitzCo-founder & General PartnerCo-founder and CEO of Opsware. Author of "The Hard Thing About Hard Things" (2014) and "What You Do Is Who You Are" (2019).LinkedIn ↗
Chris DixonGeneral Partner, a16z cryptoLeads a16z crypto. Founder of Hunch (acquired by eBay) and SiteAdvisor (acquired by McAfee). Advocate for the "read-write-own" internet.LinkedIn ↗
Martin CasadoGeneral PartnerCo-founder of Nicira, acquired by VMware for $1.26B. Helped develop OpenFlow and pioneer software-defined networking. Focuses on enterprise infrastructure and AI.LinkedIn ↗
Katherine BoyleGeneral Partner, American DynamismCo-founded the American Dynamism practice, investing in defense, aerospace, and infrastructure. Previously a partner at General Catalyst and a reporter at The Washington Post.LinkedIn ↗
Andrew ChenGeneral PartnerFormer Head of Rider Growth at Uber. Author of "The Cold Start Problem" (2021). Focuses on consumer, marketplaces, and growth.LinkedIn ↗Marc Andreessen's 2011 Wall Street Journal essay articulated the firm's core belief: software companies will dominate every industry.
During the 2020 pandemic, Marc Andreessen published a call to action for American institutions to regain the capacity to create. This builder-centric optimism defines the firm's culture.
Ben Horowitz's 2014 book crystallizes lessons from running Opsware through near-death experiences. This operating DNA permeates the firm.
Ben Horowitz
Co-founder and General Partner
Beyond capital, the firm maintains teams of operators — from marketing and talent to legal and policy — dedicated to helping founders at every stage.
Dedicated teams across distinct verticals: AI, bio + healthcare, consumer, crypto, enterprise, fintech, infrastructure, and American Dynamism.
The firm operates a substantial content network including podcasts, newsletters, books, and proprietary media to share founder perspectives and industry insights.
The American Dynamism practice invests in mission-driven founders tackling national priorities across defense technology, aerospace, manufacturing, and infrastructure.
The firm's Menlo Park office is located at 2865 Sand Hill Road, Suite 101, in Menlo Park, California.
The firm emphasizes substantive feedback, showing up on time, and maintaining long-term partnership through company challenges. As they state: "Our obligation is to the company, not the founder."
Working at a16z means being connected to portfolio companies across every stage and sector — from seed to IPO, spanning AI, fintech, healthcare, infrastructure, and more.
The firm has invested in college talent programs and recruiting infrastructure to connect founders with the team members they need.
The firm frames itself as committed to sustained engagement across cycles, helping executives find appropriate roles and supporting corporate partners' innovation goals.