<h1>US Markets Rebound After Chinese AI Startup DeepSeek Challenges Tech Giants; S&P 500 and Nasdaq Futures Rise.</h1> US markets stabilized Tuesday after a significant decline on Monday, triggered by a Chinese AI startup's announcement, which challenged American tech giants. Futures for the S&P 500 and Nasdaq rose slightly, recovering from previous losses. Major tech companies like Nvidia and Broadcom regained some ground after substantial dips. General Motors' shares remained steady despite a fourth-quarter loss due to China-related charges. Royal Caribbean's stock increased following strong profit results. In Europe, major indices saw gains, while Japan's Nikkei fell. The Chinese AI firm DeepSeek's new language model has raised questions about the future impact on the AI industry and global economy.