The emergence of China-based AI app DeepSeek sent shares plummeting on Monday for many U.S. tech giants, including chipmaker Nvidia and AI-backer Microsoft. Nvidia, which helped catapult market wide gains in recent years,

DeepSeek topped the Apple AppStore chart and sparked fears the Chinese company is quickly catching up with OpenAI's ChatGPT while costing far less.

NEW YORK (AP) — Wall Street is tumbling on fears the big U.S. companies that have feasted on the artificial-intelligence frenzy are under threat from a competitor in China. The S&P 500 fell 1.8% in early trading Monday.