OpenAI raised a record-breaking $40 billion round in March 2025, hitting a $300 billion valuation. SoftBank led the round, joined by Thrive Capital, Microsoft, and Coatue.
Anthropic pulled in $3.5 billion in a Series E round led by Lightspeed, pushing its valuation to $61.5 billion.
Thinking Machines Lab secured a massive $2 billion seed round, led by Andreessen Horowitz and backed by Nvidia, Accel, and AMD, reaching a $12 billion valuation. 
Several other U.S. AI startups raised $100 million or more rounds in the first eight months of 2025, confirming continued funding momentum.
In August, healthcare and housing automation startup EliseAI raised $250 million Series E at a $2.2 billion valuation, led by Andreessen Horowitz. AI research lab Decart raised $100 million at a $3.1 billion valuation with Sequoia Capital and Benchmark among investors.
July saw multiple mega-rounds: generative media platform Fal raised $125 million Series C at $1.5 billion valuation. AI healthcare OS builder Ambience Healthcare scored $243 million Series C, led by Oak HC/FT and Andreessen Horowitz. Reka AI raised $110 million Series B at a $1 billion valuation.
OpenEvidence, an AI-powered clinical search tool, raised $210 million Series B at a $3.5 billion valuation, led by Kleiner Perkins and GV. AI reasoning engine builder Harmonic closed a $100 million Series B round at an $875 million valuation.
In June, healthcare AI unicorn Abridge raised a $300 million Series E at $5.3 billion valuation, marking its second mega-round of 2025. Legal AI company Harvey raised another $300 million Series E round at a $5 billion valuation. Healthcare startup Tennr closed a $101 million Series C at $605 million valuation.
Enterprise search startup Glean raised $150 million Series F at $7.25 billion valuation. AI research lab Anysphere raised $900 million Series C at nearly $10 billion valuation.
May rounds include AI data-labeling startup Snorkel AI ($100 million Series D at $1.3 billion valuation), benchmarking tool LMArena ($100 million seed round at $600 million valuation), and AI infrastructure startup TensorWave ($100 million Series A).
In April, AI model company SandboxAQ raised $450 million Series E at $5.7 billion valuation, backed by Nvidia and Google. Media AI startup Runway closed $308 million Series D at a $3 billion valuation.
February rounds: open source AI infrastructure startup Together AI raised $305 million Series B at $3.3 billion valuation. AI infrastructure leader Lambda raised $480 million Series D at $2.5 billion valuation. Transcription platform Abridge raised $250 million Series D at $2.75 billion valuation.
These rounds show AI startups continue to secure massive funding in 2025, maintaining last year’s explosive growth.
TechCrunch event in San Francisco, October 27-29, 2025, will track these trends live.
