US stock market today: US stocks fell for the second day in a row on Friday, October 30, as investors worried about the health of the AI trade. At 10:58 AM ET, the Dow Jones was at 52,113.50, down 229.06 points or 0.44%. The S&P 500 was at 7,621.06, down 99.33 points or 1.29%. The…