Andreessen Horowitz (also known as a16z) is an American privately-held venture capital firm headquartered in Menlo Park, California. Founded in 2009 by Marc Andreessen and Ben Horowitz, the firm invests in both early-stage startups and established growth companies across healthcare, consumer, cryptocurrency, gaming, fintech, education, and enterprise software. The name "a16z" derives from the 16 letters between the first letter of Andreessen and the last letter of Horowitz. As of January 2026, the company manages $90 billion in assets under management.
The firm has become one of the most influential venture capital entities globally, with a particular focus on Artificial intelligence and emerging technologies. Its portfolio includes numerous AI-driven startups, and it has launched specialized funds to support companies building in the national interest, such as the American Dynamism initiative.
Founding and growth
Between 2006 and 2010, Marc Andreessen and Ben Horowitz actively invested in technology companies, both separately and together, committing $4 million across 45 startups, including Twitter. During this period, they became known as "super angel" investors. On July 6, 2009, they launched their venture capital fund with an initial capitalization of $300 million. In November 2010, amid a contracting venture capital landscape, the firm raised an additional $650 million for a second fund, bringing total assets under management to $1.2 billion within two years. By March 27, 2014, following the close of its fourth fund at $1.5 billion, the firm managed $4 billion.
General partners include Jeff Jordan, Chris Dixon, Martin Casado, and Andrew Chen. Ex-VMware CEO Raghu Raghuram joined as general partner in October 2025. Margit Wennmachers served as operating partner from 2010 to July 2025, when she became partner emeritus. In March 2019, the firm opened an office in San Francisco. In January 2022, it raised $9 billion across venture, growth, and biotech funds, and in January 2026, it raised $15 billion across five new funds, bringing total assets to at least $90 billion as of March 2026.
Investment strategy and influence
By 2012, Business Insider described Andreessen Horowitz as "the most powerful and respected venture capital firm in Silicon Valley right now." The firm is often cited as the largest and one of the most powerful venture funds globally, with Marc Andreessen frequently noted as a dominant, if controversial, figure in both Silicon Valley and politics. According to OfficeChai calculations up to October 2025, since 2020 the firm has backed 32 unicorns, more than any other venture firm. By November 2025, its website listed 1,076 portfolio companies, with a disclaimer that exits include current and former portfolio companies that have been acquired or undergone an initial public offering.
Leslie Feinzaig of Fast Company observed that Andreessen Horowitz and other large firms no longer act like traditional venture capital, investing beyond early-stage private companies into public equities, crypto tokens, and non-traditional assets. The firm presents its primary political agenda as defending "Little Tech" (startups) against Big Tech incumbents. In April 2025, it launched the American Innovators Network with Y Combinator and AI companies like Anyscale, Exowatt, and Sourcegraph, representing "America's Little Tech ecosystem." John Mac Ghlionn of the Boston Globe linked the firm to an "AI-driven military-industrial complex," citing investments in Anduril, Shield AI, Saronic, Scale AI, and others.
American Dynamism fund
In 2023, Andreessen Horowitz launched a $600 million American Dynamism fund "with the broad aim of supporting companies building in the nation's interest." The fund has raised two funds totaling $1.8 billion, focusing on hard tech sectors such as space, defense, manufacturing, and robotics. In 2024, the firm introduced the 12-month American Dynamism Engineering Fellows Program to recruit and train technologists. The annual American Dynamism summit gathers startup founders, investors, Members of Congress, and Defense Department officials; it is officially non-partisan and has partnered with Democratic defense officials like former Deputy Secretary of Defense Kathleen Hicks.
The fund is managed by general partners Katherine Boyle, David Ulevitch, and Erin Price-Wright, with Ulevitch as leader. Connor Love joined the team in July 2026. Boyle, who previously interned at Founders Fund and joined General Catalyst in 2016 before moving to Andreessen Horowitz, has a portfolio including Hadrian, Apex Space (satellites), and Castelion (hypersonic weapons). Her essay "Building American Dynamism" argues that technologists building in the national interest can reverse stagnation post-Covid.
Notable American Dynamism investments include Applied Intuition, which after its 2025 Series F ($600 million) reached a $15 billion valuation. Originally focused on AI software for automobile companies like Toyota and Porsche in autonomous driving, its defense division now applies this technology to the US military, mapping aerial, maritime, and land environments and simulating new ones.
AI investments and focus
Andreessen Horowitz has made significant investments in Generative AI and Large language model companies, including OpenAI and Anthropic, as well as infrastructure providers like Coreweave and Cerebras. The firm's AI practice, led by general partners such as Martin Casado, supports startups across the AI stack, from chips to applications. Its portfolio includes companies like Figure AI in robotics and Sanctuary AI in humanoid AI, reflecting a broad bet on Artificial intelligence as a transformative technology.
The firm's approach often involves taking board seats and providing operational support, distinguishing it from traditional venture firms. It has also invested in Machine learning and Deep learning startups, as well as Neural network research, aligning with its thesis that AI will reshape industries from healthcare to defense. As of 2026, a16z continues to be a dominant force in AI venture funding, with its American Dynamism fund specifically targeting AI-driven defense and national security applications.