Safe Superintelligence funding leads latest billion-dollar startup rounds

Safe Superintelligence funding led the latest U.S. startup financing tally, with Crunchbase reporting a $5 billion Nvidia-backed deal for the AI lab. For retail investors, the list is a window into where private capital is concentrating before many companies ever reach public markets: AI infrastructure, compute-heavy software and energy systems built to support power demand.

Crunchbase said the week’s two largest announced U.S. rounds crossed the billion-dollar mark. Safe Superintelligence, the Silicon Valley startup founded by OpenAI co-founder Ilya Sutskever, announced a long-term strategic partnership with Nvidia, and TechCrunch reported that the arrangement included a $5 billion investment from the chipmaker aimed at expanding the startup’s compute resources.

Commonwealth Fusion Systems ranked second with $1 billion in new funding from investors that were not named, according to Crunchbase. The Massachusetts company is developing fusion energy technology and working on a grid-scale fusion power plant. Crunchbase said the latest round brings Commonwealth Fusion’s total funding to date to $4 billion.

How much did Safe Superintelligence raise?

Safe Superintelligence’s deal was reported at $5 billion, according to TechCrunch, in connection with its newly announced Nvidia partnership. Nvidia’s role matters because advanced AI labs need large amounts of computing capacity, which usually means access to high-end chips and data center infrastructure.

The rest of Crunchbase’s top 10 list shows how closely AI and energy are now linked in private markets. Antora Energy, based in San Jose, closed a $550 million Series C round co-led by G2 Venture Partners and Eclipse. The nine-year-old company provides thermal battery technology for data centers, according to Crunchbase.

Function, an Austin company selling lab testing, imaging and personal health information services to consumers, raised $450 million in growth financing from General Catalyst. Antares followed with $370 million in Series C equity funding for compact nuclear fission microreactors designed for defense and space uses, with Paradigm and Caffeinated Capital leading the round. Crunchbase also said Antares raised $100 million in debt alongside the equity financing.

A Series C round is a later-stage private funding round, usually raised after a startup has already developed its product and is trying to scale. Debt financing means borrowed money that typically must be repaid, while equity financing gives investors an ownership stake.

Which other startups made the top 10?

• Simile, an AI simulation tools company, raised more than $200 million at a $2 billion post-money valuation, according to Crunchbase. Greenoaks led the round, which came five months after the Palo Alto company launched its product.
• ThreatLocker, an Orlando cybersecurity company, closed $190 million in Series F funding led by Elephant to improve its platform and expand outside the U.S.
• CAIS, a New York alternative investment platform for independent financial advisors, raised $170 million in Series D financing led by Vista Equity Partners at a valuation above $2 billion.
• PEX raised $160 million in equity and debt funding, with Bluff Point Associates leading. Crunchbase described the company as an AI-enabled provider of prepaid and charge cards for businesses, plus finance-tracking tools.
• Eliyan, a Santa Clara company building connectivity technology for AI infrastructure, completed a $145 million Series C at a $1 billion valuation, led by Seligman Ventures.

A post-money valuation is the company’s estimated value after a new funding round is included. These valuations do not guarantee future public-market prices, but they show what private investors were willing to pay in the latest financing.

This story draws on original reporting from Crunchbase News.