DeepSeek’s AI assistant became the No. 1 downloaded free app on Apple’s iPhone store Monday, propelled by curiosity about the ChatGPT competitor. Part of what’s worrying some U.S. tech industry observers is the idea that the Chinese startup has caught up with the American companies at the forefront of generative AI at a fraction of the cost.

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.

U.S. tech stocks, including Nvidia, Oracle and Google, 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.