Biggest Funding Rounds of the Week: Safe Superintelligence and Commonwealth Fusion Lead With Billion-Dollar Deals
The week's largest startup funding rounds in the U.S. included a $5 billion deal for Safe Superintelligence and a $1 billion investment in Commonwealth Fusion Systems. Other significant rounds went to companies in energy storage, health testing, and AI.

The past week saw significant venture capital flowing into U.S. startups, with Safe Superintelligence securing a reported $5 billion from Nvidia and Commonwealth Fusion Systems raising $1 billion for its fusion energy technology.
Safe Superintelligence, an AI research company founded by OpenAI co-founder Ilya Sutskever, announced a partnership with Nvidia reportedly including a $5 billion investment. This funding is intended to accelerate the company's growth and enhance its computing resources.
Commonwealth Fusion Systems, focused on developing grid-scale fusion power plants, closed a $1 billion funding round from undisclosed investors. This brings the company's total raised capital to $4 billion.
Other notable rounds included Antora Energy's $550 million for thermal energy storage, Function's $450 million for health testing services, and Antares' $370 million for nuclear energy applications. AI simulation developer Simile also raised over $200 million.