a16z co-founder, PCAST tech advisor, AI market optimist
Marc Andreessen
Biographies
Profile
Marc Andreessen is the venture capitalist who, more than any other single person, decides which AI startups get to exist. Along with Ben Horowitz, he runs Andreessen Horowitz — a16z — the Silicon Valley firm whose cheques and narrative firepower have shaped the current AI boom. The firm’s 2024 raise dedicated $7.2 billion across funds, with billions earmarked specifically for AI apps and infrastructure, and its portfolio now touches most of the names developers actually use: OpenAI, Mistral, Character.AI, Databricks, Anysphere (Cursor), ElevenLabs, and dozens more. When a founder pitches an AI company, a16z is either the money or the measuring stick.
Before the VC career, Andreessen was a programmer. As a 22-year-old at the University of Illinois in 1993, he co-wrote Mosaic with Eric Bina — the first widely used graphical web browser. A year later he co-founded Netscape with Jim Clark, and its 1995 IPO is generally taken as the opening gun of the commercial internet. AOL bought Netscape for $4.3 billion in 1999. He then co-founded Loudcloud/Opsware (sold to HP for $1.6B in 2007), before starting a16z with Horowitz in 2009. For developers, that dot-com-era history is the important part: Andreessen has now lived through three platform shifts — PC, web, mobile — and treats AI as the fourth.
He is also the loudest techno-optimist in public life. His 2011 WSJ essay “Why Software Is Eating the World” defined a decade of enterprise thinking. His 2023 essay “Why AI Will Save the World” and the follow-up “Techno-Optimist Manifesto” are the clearest articulations of the accelerationist position: regulation is the enemy, AI safety concern is “a moral panic,” and slowing down is the real risk. Fellow travellers like Sam Altman and Elon Musk share parts of this worldview; safety-focused researchers like Dario Amodei and Eliezer Yudkowsky loudly don’t. If you are trying to form a view on AI governance, Andreessen is the pole you measure the debate against.
Since 2024 he has moved sharply into politics, donating millions to Trump-aligned PACs, spending part of 2025 advising the administration on tech and crypto policy, and using a16z’s megaphone to push a “Little Tech” agenda against what he calls Washington’s war on startups. Whatever you think of the politics, the practical effect for builders is real: the rules that will govern frontier models, open-source weights, and chip export controls are being shaped in rooms Andreessen now sits in.
Key Articles & Papers
Why Software Is Eating the World Why AI Will Save the World The Techno-Optimist Manifesto The Little Tech Agenda It's Time to BuildControversies
- Trump endorsement and political spending (2024): A lifelong Democratic donor, Andreessen publicly endorsed Donald Trump, gave millions to Trump-aligned PACs with Horowitz, and spent time at Mar-a-Lago after the election. Cited reasons: crypto policy, tax policy, and what he describes as the Biden administration’s hostility to startups. Critics saw it as billionaire self-interest dressed up as principle. TechCrunch
- “Debanking” claims on Joe Rogan (2024): On Rogan’s podcast Andreessen claimed the CFPB was “debanking” tech founders for political views. The claim was widely disputed — the Biden-era CFPB had in fact proposed rules against politically motivated account closures. ProPublica
- Tone of the Techno-Optimist Manifesto: The manifesto’s list of “enemies” explicitly named “trust and safety,” “tech ethics,” and “sustainability,” which safety researchers and ethicists read as a direct attack on their field. Fortune and others criticised it as utopian libertarianism dressed as engineering philosophy. Fortune
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