Most U.S. artificial-intelligence stocks fell in premarket trading, with Nvidia declining to $214.34, AMD to $501.81 and Intel to $99.33, according to MSX.COM data. The implied market capitalization of Anthropic’s pre-listing over-the-counter contracts dropped 3.75% in 24 hours to $2.0783 trillion, while OpenAI’s fell 10.6% to $1.4391 trillion. The moves followed unusually synchronized calls from Anthropic and OpenAI to slow the pace of advances in AI capabilities. Anthropic Chief Executive Officer Dario Amodei said the industry should allow companies more time for model alignment and safety protections, rather than stop training or technological development. OpenAI founder Sam Altman endorsed the view, saying progress in frontier models should be controlled and that OpenAI would consider giving independent evaluators employee-like access.