US AI Startups Secure Over $100M in Mega-Rounds for 2025

A new report highlights 33 US AI companies attracting significant investments this year, continuing a strong trend.

The US AI startup landscape continues its impressive growth in 2025, with 33 companies raising $100 million or more. This follows a monumental 2024, indicating sustained investor confidence in artificial intelligence.

August 28, 2025

4 min read

US AI Startups Secure Over $100M in Mega-Rounds for 2025

Key Facts

  • 33 US AI startups have raised $100 million or more in 2025.
  • 2024 saw 49 US AI startups raise $100 million or more, with seven exceeding $1 billion.
  • Thinking Machines Lab raised a $2 billion seed round in July 2025, valuing it at $12 billion.
  • Abridge, a healthcare AI company, raised a $300 million Series E round in June 2025, valuing it at $5.3 billion.
  • Harvey, an AI legal tool company, raised its second $300 million round in June 2025, reaching a $5 billion valuation.

Why You Care

Ever wonder where the next big technological leap will come from? Do you think artificial intelligence (AI) is just a buzzword, or is it truly reshaping industries? Well, buckle up, because a new report reveals that 33 US AI startups have already secured funding rounds of $100 million or more in 2025. This isn’t just about venture capitalists making big bets. This surge in investment directly impacts the tools and services you’ll use in the near future, from healthcare to legal services. It shows where creation is truly accelerating and why you should pay attention.

What Actually Happened

The US artificial intelligence sector is experiencing another year of significant financial growth. According to the announcement, 33 US-based AI startups have successfully raised funding rounds of $100 million or more in 2025. This continues the momentum from a “monumental” 2024, as mentioned in the release. Last year, 49 startups achieved similar mega-rounds, with seven companies raising $1 billion or more. The company reports that 2025 is already seeing multiple billion-dollar rounds. What’s more, several companies have raised more than one mega-round within the year. This indicates investor confidence in the long-term potential of AI technologies.

Why This Matters to You

This influx of capital isn’t just a headline for investors; it directly translates into advancements that could affect your daily life. For instance, imagine a world where your doctor can use an AI-powered search tool to quickly find the most relevant clinical information for your specific condition. OpenEvidence, an AI-powered search tool for clinicians, recently raised significant funding, according to the announcement. Or consider how legal processes might become more efficient. Harvey, a company building AI tools for the legal industry, secured its second $300 million round in 2025, as mentioned in the release. This kind of investment fuels the creation of practical applications that solve real-world problems.

What everyday tasks do you think AI could simplify or improve for you in the coming years?

Here are some of the key areas attracting major AI investment in 2025:

Industry SectorExample Company (2025 Funding)
Healthcare AIAmbience Healthcare, Abridge, OpenEvidence
Legal AIHarvey
Enterprise SearchGlean
AI Research LabsDecart, Reka AI, Thinking Machines Lab
Media/ContentFal

This table, derived from the report, highlights the diverse applications attracting substantial capital. The company reports that “Five-year-old Ambience Healthcare, which is building an AI healthcare operating system, raised a [significant round].” This shows a clear focus on practical, industry-specific AI solutions.

The Surprising Finding

Perhaps the most striking detail from the report is the sheer scale of some individual funding rounds this year. The technical report explains that “AI research lab Thinking Machines Lab confirmed that it raised $2 billion on July 15.” This sizable seed round values the company at $12 billion. This is particularly surprising because seed rounds are typically much smaller, intended for early-stage creation. A $2 billion seed round indicates an extraordinary level of investor belief in the future potential of this specific AI research. It challenges the traditional notion of startup funding stages. It suggests that some AI ventures are being valued at unicorn levels (over $1 billion) right from their inception.

What Happens Next

Given the continued investment trends, we can expect to see more AI products and services emerge in the coming months. The company reports that “with only a few weeks left in the third quarter, it looks like 2024’s momentum will continue this year.” This suggests a strong finish to 2025 and a outlook for 2026. For example, AI-powered medical scribes, like those developed by Abridge, could become standard in healthcare settings within the next 12-18 months. If you’re considering a career in tech, focusing on AI creation or application could be a smart move. The industry is clearly expanding rapidly. The team revealed that “Healthcare AI unicorn Abridge announced it raised a $300 million Series E round that values the company at $5.3 billion.” This kind of valuation signals massive growth potential and ongoing creation across various sectors.