Stock market today: Dow falls 250 points, S&P 500, Nasdaq retreat from record as Trump escalates tariff threats October 20, 2025 by jlamprecht https://finance.yahoo.com/news/live/stock-market-today-dow-sp-500-nasdaq-slide-after-trump-threatens-35-canada-tariff-higher-blanket-duties-223034696.html?.tsrc=fin-notif