US stocks today: S&P 500, Nasdaq decline as tech sector falls, US prepares to impose more Iran sanctions

Wall Street’s S&P 500 and Nasdaq declined on Monday, dragged down by a sharp sell-off in technology and semiconductor stocks.Investors reacted to fresh U.S. sanctions against Iran, mounting political pushback on AI data centers, and looming market catalysts, including Nvidia’s earnings and upcoming Fed inflation reports.