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.

Some AI researchers hailed DeepSeek’s R1 as a breakthrough on the same level as DeepMind’s AlphaZero, a 2017 model that became superhuman at the board games Chess and Go by purely playing against itself and improving, rather than observing any human games.