Andreessen Horowitz Launches $4.5B Fund Focused on AI Infrastructure

The Silicon Valley venture capital giant announces its largest dedicated fund ever, targeting companies building the foundational infrastructure for the next wave of AI applications.

Venture Capital · North America · 2026-02-25 · 2 min read · By John Awab

Andreessen Horowitz (a16z) has announced the launch of a $4.5 billion fund dedicated exclusively to AI infrastructure investments, making it the largest single-focus venture fund in the firm's history. The fund will target companies building the essential building blocks for enterprise AI adoption.

The fund, named a16z AI Infrastructure Partners, will invest across the full stack of AI infrastructure, including custom silicon design, distributed training systems, inference optimization, data pipelines, and model serving platforms. Partners Martin Casado and Anjney Midha will lead the fund.

Ben Horowitz explained the thesis: "We believe we're in the early innings of a multi-decade AI infrastructure buildout that will rival the cloud computing wave. The companies that build the picks and shovels of AI will generate enormous value."

The firm has already made several investments from the fund, including a $200 million round in Cerebras Systems for next-generation AI chips, and a $150 million investment in Together AI for distributed model training infrastructure.

The announcement comes amid a broader trend of venture capital firms raising dedicated AI funds. Sequoia Capital, Lightspeed Venture Partners, and Khosla Ventures have all announced similar vehicles in recent months, collectively bringing over $15 billion in new capital to the AI sector.