Marc Andreessen

Marc Andreessen was born July 9, 1971, in Cedar Falls, Iowa, and raised in New Lisbon, Wisconsin. He earned a B.S. in Computer Science from the University of Illinois at Urbana-Champaign in December 1993, where, while working at the National Center for Supercomputing Applications (NCSA), he co-authored Mosaic — the first widely used graphical web browser, notable for displaying inline images. In 1994 he co-founded Mosaic Communications Corporation, soon renamed Netscape Communications. Netscape's 1995 IPO became a defining moment of the early internet era, and a 24-year-old Andreessen landed on the cover of Time. AOL acquired Netscape for roughly $4.2–4.3 billion in 1999, where he served as Chief Technology Officer.

After Netscape, Andreessen co-founded Loudcloud (1999) with Ben Horowitz; the company survived the dot-com bust by pivoting into the software business Opsware, which Hewlett-Packard acquired for about $1.6 billion in 2007. He also co-founded Ning, a social-networking platform, which sold to Mode Media for an estimated ~$150 million around 2011. Between roughly 2005 and 2009 he was a prolific "super angel," reportedly investing around $80 million across some 45 startups alongside Horowitz.

In 2009 Andreessen and Horowitz launched Andreessen Horowitz (a16z) with an initial ~$300 million fund, built on a contrarian thesis: that the best venture firm would win by genuinely helping founders operationally rather than through financial engineering. The firm has since grown into one of the largest and most influential venture firms in the world. Andreessen remains a co-founder and general partner.

Beyond investing, Andreessen is a prominent public intellectual on technology and policy. He authored the widely cited 2011 Wall Street Journal essay "Why Software Is Eating the World" and the 2023 "Techno-Optimist Manifesto." He has served on numerous boards including Meta (Facebook), Hewlett-Packard (2008–2018), eBay (2008–2014), Oculus VR, OpenGov, and Dialpad. He shifted publicly toward Republican politics, backing Donald Trump in 2024, and in 2026 was associated with the President's Council of Advisors on Science and Technology.

• "Software is eating the world." His foundational thesis (2011) is that software-driven companies will progressively take over large swathes of the economy across nearly every sector — the lens through which a16z evaluates opportunities.
• Techno-optimism / acceleration. His 2023 "Techno-Optimist Manifesto" argues that technology — and especially AI — is the engine of human progress and should be accelerated, not constrained.
• AI as the defining shift. In his 2026 outlook he framed AI as the largest technology shift of his career, citing the collapsing "cost of intelligence" and arguing the market is still early despite rapid adoption.
• Founder-first, operationally heavy. a16z's differentiating bet is backing technical, ambitious founders with deep operational support rather than passive capital.
• Stage- and sector-flexible via specialized funds. He invests across seed-to-growth through a16z's dedicated vehicles spanning consumer, enterprise, fintech, crypto, bio/health, and American Dynamism.
• Contrarian and conviction-driven. Known for backing bold, sometimes controversial categories (e.g., crypto) ahead of consensus.