Marc L. Andreessen is a co-founder and general partner at Andreessen Horowitz (a16z). See sector focus and contact routes.
Marc L. Andreessen is a co-founder and general partner at Andreessen Horowitz (a16z), the venture capital firm he launched in 2009 with Ben Horowitz after previously co-founding Netscape and creating the Mosaic web browser. The firm invests across all stages from seed to growth in sectors including consumer, enterprise software, crypto, bio, defense, and AI, with a global scope centered in Silicon Valley but extending internationally. Andreessen typically leads early rounds and has backed companies with check sizes ranging from hundreds of thousands to tens of millions, often acting as a lead investor rather than a follower. Notable portfolio companies include Facebook, Airbnb, GitHub, and Coinbase, all of which received early funding from a16z under his involvement. He is known for the contrarian view that the best venture firms should prioritize genuinely helping founders over financial engineering, a thesis that shaped a16z’s operator-heavy model. His public writing includes the influential essay “Software Is Eating the World,” which articulated a long-term belief in software’s transformative impact across industries.
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