Chinese AI startup called DeepSeek became the most downloaded free app in the U.S. Apple store on Monday, replacing ChatGPT. That's rattling U.S. tech companies.

By Sinéad Carew, Amanda Cooper, Ankur Banerjee NEW YORK/LONDON/SINGAPORE (Reuters) -Investors sold off a host of technology stocks from Tokyo to New York on Monday as they worried that the emergence of a low-cost Chinese artificial intelligence model would threaten the dominance of current AI leaders such as Nvidia.