In Amsterdam, Dutch chip supplier ASML slid 8.5%. In Tokyo, Japan’s Softbank Group Corp. lost 8.3% and is nearly back to where it was before spurting on an announcement that it was joining a partnership trumpeted by the White House that would invest up to $500 billion in AI infrastructure.

Stiffer competition for the tech giants at the forefront of the artificial intelligence boom prompted investors to reassess the companies’ sky-high valuations.

Investors dumped technology stocks in premarket trading Monday, sending U.S. indexes sharply lower after Chinese artificial intelligence startup DeepSeek demonstrated a chatbot that it says rivals the

U.S. tech stocks, including Nvidia, Oracle and Broadcom, plummeted Monday after Chinese startup DeepSeek said it created an AI system that can compete against chatbots such as OpenAI's ChatGPT at much lower costs.