Shares of chipmaker Nvidia plunged Monday, for its worst day since the global market selloff in March 2020 that the coronavirus pandemic triggered.

A new AI model from Chinese company DeepSeek is hitting the stock of AI boom darling Nvidia. DeepSeek can run on less-advanced chips, and investors seem to be questioning whether demand for Nvidia's high-end chips is overdone. The chipmaker's shares took a beating in premarket trading, dropping 13%.

With Monday’s losses, Apple has retaken the title of world’s most valuable company and Nvidia’s value sank to around $2.8 trillion.