US markets lose nearly $1tn as tech sell-off deepens on AI return worries

US markets fell by nearly $1tn in a week as a tech stock sell-off intensified following disappointing earnings from major companies, with the Nasdaq losing about $2tn in a month. The S&P 500 dropped over 1% Friday, erasing its October gains, while the Nasdaq fell more than 3%. Intel plunged nearly 30% on weak forecasts, and Alphabet lost $500bn in market value a day earlier. Investors are questioning whether massive AI investments will generate returns quickly enough, with Nvidia falling 3.1% and concerns rising that high interest rates may slow data center expansion.