Venture capital excitement in artificial intelligence continues to surge as 2025 unfolds. Following a staggering year in 2024, where nearly fifty AI startups landed massive investments, US-based innovators remain in the fundraising spotlight.
Momentum is showing no signs of slowing, with billion-dollar rounds and significant funding closures already distinguishing the early months of the year. Compared to the first quarter of 2024, even more major investment activity has already occurred among domestic AI firms in 2025.
Major Funding Rounds Define the Field
Leading the charge in April, SandboxAQ secured a $450 million Series E round that took its market worth to $5.7 billion, attracting major investors, including Nvidia and Google. Runway, which powers AI-driven media production, achieved a $308 million Series D round, propelling its valuation to $3 billion, with industry heavyweights supporting the deal.
March witnessed OpenAI capturing headlines with a record OpenAI funding of $40 billion, valuing the company at a staggering $300 billion and backed by some of the most prominent names in tech and finance. Infrastructure players are also rising, such as Nexthop AI, which locked in $110 million in Series A funding from top-tier venture capitalists.
Drug discovery platform Insilico Medicine, headquartered in Massachusetts, raised $110 million that brought its value to $1 billion as of mid-March. Celestial AI joined the high-stakes arena with $250 million in funding, bringing its valuation to $2.5 billion and attracting significant institutional interest.
Pioneering science and autonomous tech remain a hotbed for investment, as Lila Sciences and Brooklyn’s Reflection.Ai each drew robust rounds of $200 million and $130 million, respectively. AI coding leader Turing capitalized on momentum, closing a Series E worth $111 million, pushing its valuation above $2 billion.
Fresh capital also flowed to Shield AI, notching $240 million and solidifying its position in AI defense at $5.3 billion, while Anthropic achieved a landmark $3.5 billion Series E, driving its worth to over $61 billion. These events reflect not only the scale of private investment but the wide range of applications that capture investor interest.
February continued the high-tempo trend with Together AI drawing $305 million, Lambda securing $480 million, and Abridge attracting $250 million as each company advanced their AI infrastructure, healthcare, and platform ambitions. Legal-tech also made strides, with Eudia and Harvey both surpassing the $100 million threshold in their respective rounds.
The year opened with bold moves in January, as ElevenLabs successfully captured $180 million to accelerate synthetic voice technology, pushing its valuation above $3 billion. In healthcare AI, Hippocratic AI stood out by securing $141 million, further establishing large language models as industry-shaping tools.
Several of these deals also saw repeat attention from major investors who continue to support promising advancements across the AI landscape. With these milestones, 2025 appears poised to rival or even surpass last year’s record-setting pace in AI startup investments.
