US stocks tumbled on Thursday as a fresh wave of concerns over the scale of AI spending hit technology shares, sending the Nasdaq to its steepest one day decline since June, Reuters reported.The Nasdaq Composite fell 2.58% to 26,008.86, while the S&P 500 dropped 1.19% to 7,664.77. The Dow Jones Industrial Average bucked the trend, edging up 0.03% to 52,873.60.US MarketsPowered ByAs on 23 Oct 2026, 01:30 AM ISTS&P 500 Top GainersPool197.21(14.36%)Allegion176.42(10.96%)Roper Technologies436.23(9.73%)Mohawk Industries128.68(9.01%)Gainers»S&P 500 Top LosersModerna202.63(-17.57%)Lam Research230.15(-11.76%)GE Vernova827.45(-10.63%)Teradyne308.75(-10.63%)Losers»The selloff was concentrated in technology and semiconductor stocks, with the Philadelphia SE Semiconductor Index plunging.