SINGAPORE (Reuters) - Nasdaq futures slumped and technology shares slid in Japan on Monday as surging popularity of a Chinese discount artificial intelligence model wobbled investors' faith in the profitability of AI and the sector's voracious demand for high-tech chips.Nasdaq 100 futures were down 2.4% and S&P 500 futures by the Asia afternoon, and shares in Nvidia (NASDAQ:NVDA) supplier Advantest fell 8.5% in Tokyo.Startup DeepSeek has rolled out a free assistant it says uses lower-cost chips and less data, seemingly challenging a widespread bet in financial markets that AI will drive demand along a supply chain from chipmakers to data centres."It's a case of a crowded trade, and now DeepSeek is giving a reason for investors and traders to unwind," said Wong Kok Hoong, head of equity sales trading at Maybank. AI-focused startup investor SoftBank (TYO:9984) Group slid more than 8%, on course for its biggest one-day fall since Sept. 30. Last week it announced a $19 billion commitment to fund Stargate, a data-centre joint venture with OpenAI.Chip-making equipment giant Tokyo Electron fell 5%.Tech-heavy markets in Taiwan and South Korea were closed.European tech stocks, especially Dutch computer chip equipment maker ASML (AS:ASML), which counts Taiwan's TSMC, Intel (NASDAQ:INTC) and Samsung (KS:005930) as its customers, will likely face pressure at the open.Shares of Nvidia, the poster child of AI, have risen 196% since the start of 2024, outperforming the 35% gain in the Nasdaq.CAPEX IN QUESTIONLittle is known about the small Hangzhou startup behind DeepSeek, but its assistant leapfrogged rival ChatGPT to become the top-rated free application on Apple (NASDAQ:AAPL)'s App Store in the United States on Monday.investing.com