Here are the 33 US AI startups that have raised $100M or more in 2025

The U.S. AI industry is sustaining its robust funding momentum into 2025, following a monumental 2024 that saw 49 startups raise over $100 million, including seven billion-dollar rounds. This year has already witnessed significant capital injections, such as OpenAI's $40 billion funding round at a $300 billion valuation, Anthropic's $3.5 billion at $61.5 billion, and Thinking Machines Lab's $2 billion seed round, alongside numerous other mega-rounds across diverse sectors like healthcare, legal tech, and AI infrastructure. The continued participation of top-tier venture capitalists and strategic investors underscores strong confidence in the sector's rapid growth and transformative potential.

Analysis

The private market for Artificial Intelligence continues to demonstrate exceptional funding momentum through the first three quarters of 2025, building upon a landmark 2024. Capital deployment is characterized by both significant scale and broad diversification across the AI value chain. At the top end, foundational model and research labs are securing unprecedented valuations, exemplified by OpenAI's $40 billion round at a $300 billion valuation and Anthropic's $3.5 billion round at $61.5 billion. Notably, the high-risk, high-reward appetite of investors is underscored by Thinking Machines Lab's $2 billion seed round. Beyond these flagships, capital is flowing robustly into specialized verticals, with healthcare AI emerging as a dominant theme through substantial funding for companies like Abridge ($300M), Ambience Healthcare ($243M), and OpenEvidence ($210M). AI infrastructure, encompassing everything from hardware (Celestial AI, Lambda) to enterprise tools (Glean, Anysphere), is also a primary recipient of investment. The consistent participation of premier venture firms like Andreessen Horowitz and Kleiner Perkins, alongside strategic corporate investors such as Nvidia, Microsoft, and Alphabet, validates the sector's long-term strategic importance and signals an ongoing competitive race to fund the ecosystem's key enablers.

Key Decisions for Investors

• Investors should view the active participation of public companies like Nvidia (NVDA), Microsoft (MSFT), and Alphabet (GOOGL) in these funding rounds as a strong positive signal, reinforcing their strategic positioning as central beneficiaries of the entire AI ecosystem's growth.
• The significant capital infusions into vertical-specific AI applications, particularly in healthcare and legal tech, indicate a high potential for disruption in these sectors; it is prudent to evaluate the AI strategy and competitive moat of incumbent public companies in these fields.
• The sheer volume of funding directed towards AI infrastructure—from chips and data centers to developer tools—suggests that the core build-out phase is far from over, presenting continued opportunities in public companies that supply this foundational layer.
• The rapid pace of multiple mega-rounds within a single year for startups like Harvey and Abridge points to accelerated valuation growth in the private market, which could create both high-return M&A opportunities for strategic acquirers and valuation risks for future IPOs.