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

The Dow Jones Industrial Average plunged more than 300 points, or 0.7%, Tuesday as fears over an AI bubble shook the market and traders fretted that rate cuts from the Federal Reserve aren’t a sure thing.

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.

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

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.

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,

With the Dow closing down nearly 500 points Tuesday and the S&P logging its longest slide since August, experts are pointing to concerns over an AI bubble. NBC’s Brian Cheung joins TODAY to break it all down.

Nvidia reported more eye-catching numbers for its fiscal third quarter Wednesday, with net income jumping 65% and revenue increasing 62% from a year earlier