OpenAI just became the world’s most valuable startup at $500 billion. But Thinking Machines Lab’s rapid rise to $12 billion shows AI’s venture capital boom continues unabated.
What’s Happening: Seventy-nine companies achieved unicorn status, private valuations exceeding $1 billion, in 2025, with AI startups capturing the largest share. Mira Murati’s Thinking Machines Lab, founded in February 2025, leads with a $12 billion valuation by October, whilst OpenAI surpassed SpaceX to become the world’s most valuable private company at $500 billion.
Why This Matters: The unicorn boom reveals where venture capital sees sustainable returns: AI and enterprise technology now represent over half of billion-dollar startups. This concentration signals investors are prioritising proven revenue models and scalability over speculative bets, reshaping which founders can access growth capital and which industries will define the next decade.
Thinking Machines Lab’s trajectory from February founding to $12 billion valuation by October 2025 exemplifies venture capital’s unprecedented appetite for artificial intelligence.
The San Francisco-based company, established by former OpenAI executive Mira Murati, represents the fastest path to multibillion-dollar status amongst this year’s cohort of 79 new unicorns, according to research from BestBrokers analysing CB Insights data.
The company’s valuation towers over Pittsburgh healthcare AI firm Abridge ($5.3 billion), San Francisco fashion retailer Quince ($4.5 billion), and medical information platform OpenEvidence ($3.5 billion), which round out the top newly minted unicorns of 2025.
Twenty-two of the 79 companies reaching unicorn status work in artificial intelligence, making it the dominant sector, followed by enterprise technology with 18 startups. The geographical concentration remains striking: 53 companies (67.1%) operate from the United States, whilst the remaining third spread across China, India, Germany, and the United Kingdom.
Paul Hoffman from BestBrokers.com contextualises the pattern: “Following OpenAI’s milestone $500 billion valuation, AI, enterprise technology, and fintech have emerged as the defining forces in the 2025 unicorn landscape.
“Among the 79 companies reaching unicorn status this year, over a third are AI-focused, including Thinking Machines Lab ($12 B), Abridge ($5.3 B), and Decart ($3.2 B), while enterprise tech firms such as Filevine ($3 B), Supabase ($2 B), and Framer ($2 B) continue to attract substantial capital.”
Investment thesis shifts
The research highlights what Hoffman describes as a “flight to quality”: investors increasingly backing startups that combine deep innovation with scalable, sustainable business models. This marks a departure from previous years when venture capital flowed more liberally to early-stage companies with unproven revenue streams.
OpenAI’s ascension to the world’s most valuable private company, surpassing both SpaceX and TikTok parent ByteDance, underscores the market’s confidence in commercialised AI applications. At $500 billion, the ChatGPT developer’s valuation reflects not just technological promise but demonstrated user adoption and revenue generation.
Beyond the AI sector, enterprise technology continues drawing substantial capital. Salt Lake City’s Filevine ($3 billion), San Francisco’s Supabase ($2 billion), and Amsterdam’s Framer ($2 billion) represent investors’ belief in B2B software that solves operational challenges for other businesses.
Looking forward
“The next wave of private company investment is likely to continue favouring firms with a proven revenue potential and the capacity to scale globally in high-demand markets,” Hoffman notes.
The BestBrokers analysis, compiled from CB Insights’ July 2025 data and Pitchbook records, reveals a market where valuations increasingly depend on demonstrable business fundamentals rather than speculative potential alone. For founders seeking venture backing, the message appears clear: innovation must pair with viable paths to profitability.
The complete dataset and methodology are available through BestBrokers’ full report, offering detailed breakdowns of funding rounds, valuations, and sector trends shaping private company investment throughout 2025.
More information on private companies and their valuations, as well as the complete methodology, can be found in the full report.
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