The Financial Post reports in its Tuesday edition that Chinese artificial intelligence start-up DeepSeek's latest AI model sparked a $1-trillion (U.S.) rout in U.S. and European tech stocks, as investors questioned bloated valuations for some of America's biggest companies. A Bloomberg dispatch to the Post says that DeepSeek's latest AI model rose to the top of Apple's App Store charts over the weekend, presenting a visible challenge to costlier models like OpenAI and raising questions over the hundreds of billions in planned spending on the technology by the likes of Microsoft, Meta and Alphabet. It also put a spotlight on AI chip producer Nvidia, the world's most valuable company. The Nasdaq 100 and Europe's Stoxx 600 technology subindex were together set for a market capitalization wipeout of $1.2-trillion (U.S.), if the losses hold. "DeepSeek shows that it is possible to develop powerful AI models that cost less," said Vey-sern Ling at Union Bancaire Privee. "It can potentially derail the investment case for the entire AI supply chain, which is driven by high spending from a small handful of hyperscalers." The rout comes at the start of a big week for earnings from major tech firms including Apple and Microsoft.