Key Takeaways AI stocks had a volatile week as Wall Street reckoned with the implications of a sophisticated, cost-efficient AI model from Chinese start-up DeepSeek.Semiconductor stocks such as Nvidia and Broadcom sold off on Monday as investors worried DeepSeek's efficiencies would temper enthusiasm for AI infrastructure spending.

A frenzy over an artificial intelligence chatbot made by Chinese tech startup DeepSeek was upending stock markets Monday and fueling debates over the economic and geopolitical competition between the U.