In 2025, the pace of venture capital investment into artificial intelligence companies in the United States stayed extraordinarily high, continuing the momentum from the previous year. According to a comprehensive TechCrunch survey, 49 US AI startups raised funding rounds of $100 million or more throughout 2025, matching the number of similarly sized rounds seen in 2024 and signaling sustained investor appetite for high-growth AI technologies across multiple sectors.

This unprecedented level of investment reflects both the increasing sophistication of AI technologies and the strategic importance of these technologies across industries ranging from infrastructure and healthcare to productivity tools and enterprise software. This article explores the major trends in US AI startup funding 2025, identifies key categories attracting capital, and discusses what this means for founders, investors, and the broader economy.

The 2025 Funding Landscape: Mega Rounds and Diverse Verticals

The benchmark for a “mega round” in 2025 was a funding round of $100 million or more, and 49 US AI startups reached that threshold according to TechCrunch data compiled and published on January 19, 2026. Among the key observations from this data:

• Sustained Volume of Big Rounds: 2025 matched 2024’s level of 49 startups raising $100M+ rounds, demonstrating that the capital flow to the US AI ecosystem remains strong despite broader market volatility.
• Multiple Mega-Rounds Per Company: Unlike in 2024, several startups raised more than one large round in the same year, showing deeper investor confidence in certain companies’ trajectories.
• Billion-Dollar Plus Rounds: While fewer companies raised rounds exceeding $1 billion compared to the prior year, four startups did so in 2025, with Anthropic notably raising two rounds over that mark.
• Investor Confidence at Large Scales: Notable mentions include major rounds for foundational model companies and infrastructure providers, which collectively signal broad strategic interest from top venture capital firms and institutional investors.

The full list of companies that raised $100 million or more includes a wide array of business models and technology focuses, from foundational models and AI infrastructure platforms to domain-specific applications such as healthcare, cybersecurity, and legal tech.

Major Themes in US AI Startup Funding 2025

Continued Dominance of AI Infrastructure and Model Platforms

A significant portion of funding in 2025 went to companies focused on foundational AI model development and infrastructure. These platforms provide the underlying capabilities that other AI applications depend on, whether that involves large language models, AI chips, data services, or compute power. For example:

• OpenAI, a leader in foundational models, raised a record-breaking $40 billion round valuing the company at $300 billion, underscoring its role as a central pillar of the AI ecosystem.
• Runway, an AI media and model producer, secured a $308 million Series D that boosted its valuation to $3 billion.
• Celestial AI, which specializes in AI infrastructure focused on hardware and compute, raised a $250 million Series C round valuing the company at $2.5 billion.

These investments reflect a broader belief that platforms enabling AI capabilities at scale are foundational to future growth, whether for enterprise developers, software businesses, or specialized industry applications.

Healthcare and Domain-Specific Applications Attract Capital

2025 also showcased the diversity of AI applications beyond core infrastructure:

• Hippocratic AI, which builds healthcare-focused AI agents, raised $126 million Series C, highlighting sustained interest in AI solutions tailored to health information, diagnostics, and clinical workflows.
• OpenEvidence, an AI chatbot built for the medical field, secured a $200 million Series C round valued at $6 billion.
• Other domain-specific companies like Tennr raised over $100 million toward specialized healthcare AI tools.

These sizable rounds suggest that investors increasingly see AI not just as a technology platform but as an enabler of specialized business models addressing sector-specific challenges such as diagnostics, patient interaction, and clinical analysis.

Growth in Enterprise Tools and Legal Tech

Other startups in the list focused on tools designed to improve enterprise workflows and professional services, bridging the gap between general-purpose AI and specialized business solutions.

• Parallel, a company building web infrastructure for AI agents used in business automation, raised a $100 million Series A.
• Reflection.AI received funding exceeding $100 million for building advanced autonomous systems.
• Snorkel AI, a data labeling and AI lifecycle company, raised a $100 million Series D round valued at $1.3 billion, reflecting ongoing investment in data-centric AI tools.

These rounds demonstrate that enterprise AI tools — from intelligent automation agents to data operations platforms — continue to draw large investments as businesses seek ways to embed AI into core processes.

2025 Funding Patterns Compared to Prior Years

The sustained appearance of high-value funding rounds in 2025 mirrors patterns seen in 2024, but with key distinctions:

• Increased Follow-On Mega-Rounds: In 2025, startups secured multiple mega-rounds within the same calendar year, indicating deeper investor commitment and confidence in long-term scaling potential.
• Sector Diversification: While infrastructure, large models, and foundational technologies dominated capital markets in earlier years, 2025 brought greater attention to verticalized AI applications (healthcare, legal, cybersecurity).
• Valuations Expansion: Several companies have achieved higher valuations within shorter timeframes, suggesting accelerated growth expectations among investors.

Taken together, these patterns show that while the pace of investment remained high, its focus broadened to include both deep foundational platforms and specialized AI solutions with clear revenue models.

Investor Implications and Strategic Outlook

For venture capitalists and institutional investors, the distribution of funding in 2025 underscores several strategic insights:

• Diversification Across AI Layers: Capital is being allocated to foundational models, infrastructure platforms, enterprise tools, and industry-specific applications, revealing confidence across multiple layers of the AI value chain.
• Longer-Term Value Capture: The repeating of large rounds for certain startups signals belief in long-term competitive moats, particularly around proprietary data, scalable platforms, and differentiated AI workflows.
• Sector Adoption Indicators: Heavy investment in healthcare AI and other non-traditional tech sectors suggests that AI continues to penetrate industries once considered slow to adopt advanced technologies.

These shifts may influence how limited partners, corporate VCs, and traditional venture funds allocate resources in 2026 and beyond.

A Dynamic and Expanding AI Ecosystem

The US AI startup funding 2025 landscape paints a picture of a vibrant and highly active venture capital market. With 49 companies raising $100 million or more, sustained investor interest, and capital flowing into both infrastructure and domain-specific applications, the data shows that AI remains a central priority for funders looking to back the next generation of innovation.

Whether driven by foundational model advances, enterprise automation tools, or specialized healthcare solutions, the ecosystem continues to attract large sums of capital. For founders planning market entry or scale-up strategies in 2026, these trends represent both opportunities for differentiation and benchmarks for what investors seek in the most promising AI startups.