The release of a less capital-intensive artificial intelligence model from China’s DeepSeek sent a chill through the U.S. stock market Monday, initiating a massive selloff underscoring the fragile backdrop behind the record market.

The S&P 500 and the Nasdaq dropped on Monday, as the surging popularity of a low-cost Chinese artificial intelligence model knocked shares of chipmaker Nvidia and other companies benefiting from investments into the technology.

DeepSeek released an open-source artificial intelligence model in December after saying that it took only two months and less than $6 million to create.