An AI assistant created by Chinese startup DeepSeek became the number one most-downloaded app in Apple's US App Store over the weekend, sending shockwaves through Silicon Valley and causing the price of major tech stocks to plummet. Nvidia saw more than 460 billion erased from its market capitalization on Monday, a drop Bloomberg characterized as the "biggest in US stock market history." The shakeup stems from an open source model developed by DeepSeek called R1, which debuted earlier this month. The company said that it rivals the current industry leader: OpenAI's 01. But what stunned the tech industry the most was that DeepSeek claimed to have built its model using only a small fraction of the specialized computer chips that AI companies typically need to develop cutting-edge systems. On Monday, DeepSeek said it was temporarily limiting new registrations, citing "large-scale malicious attacks" on the company's services, according to a message on its website.