On January 27, local time, stocks with artificial intelligence themes in European and American stock markets were sold off. In the US market, the Nasdaq Composite Index fell by 3.07%. The stock of Nvidia, the leading US stock company with artificial intelligence themes, plummeted by nearly 17%, and its market value evaporated by US$592.7 billion, setting a record for the largest single-day market value loss in the history of US stocks. Broadcom's stock price fell by 17%, AMD's stock price fell by 6%, and Microsoft's stock price fell by 2%. In addition, derivatives in the field of artificial intelligence, such as power suppliers, were also hit hard, with United Energy's stock price falling by 21% and Vistra's stock price falling by 29%. US media analysis believes that this is mainly due to the impact of the artificial intelligence model of DeepSeek, a Chinese AI startup. It is reported that DeepSeek's artificial intelligence assistant has replaced OpenAI's ChatGPT and become the most downloaded free application in the US Apple App Store. It is reported that the model developed by DeepSeek has outperformed OpenAI in many tests and cost less than US$6 million. CCTV reporters interviewed Nasdaq Vice Chairman McCoy on this matter at the Nasdaq exchange. McCoy said he believes DeepSeek will be an important part of the revolution in the field of artificial intelligence.