Stocks closed markedly lower on Tuesday as fears of a bubble in artificial intelligence technology hammered markets for a fourth consecutive trading day.

The S&P 500 dipped 0.8% while the tech-heavy Nasdaq fell 1.1% as investors panicked over whether AI firms have been overvalued – extending a rocky tech rout into its third week.

All three major U.S. stock indexes were moving higher in Wednesday's final hour of trading, despite minutes from the Federal Reserve's October meet

US stock market futures fell today as the S&P 500 extended a three-day slide. Nvidia and Oracle dropped again as investors questioned high AI valuations and rising data-center debt. Dow futures slipped 140 points or 0.

The Nasdaq is higher while the Dow and S&P 500 are flat after a strong October that saw the S&P and Dow both gain over 2%. Tech continues to lead thanks to major AI deals and chip momentum: Amazon struck a $38B partnership with OpenAI,

AI pioneer Nvidia was again the heaviest weight on the market. The chipmaker's drop of 3.2% brought its loss for the month to nearly 11%, putting it in "correction" territory, or when a stock falls at least 10% from its previous high. The company is scheduled to report is third-quarter financial results on Wednesday.

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