US tech stocks sold off as warnings that the hype surrounding AI could be overdone hit some of the year's best-performing shares. From a report: Nvidia, the chips group that has surged to become the world's first $4tn company on the back of AI, fell 3.5 per cent on Tuesday, while software group Palantir dropped 9.4 per cent and chip designer Arm shed 5 per cent. The tech-heavy Nasdaq Composite closed down 1.4 per cent, the biggest one-day drop for the index since August 1. The blue-chip S&P 500…