After Trump announced comprehensive tariffs, the US stock market fell by a cumulative 10.5% over two trading days. Former US Treasury Secretary Summers posted on X on Saturday that since World War II, only during the 1987 stock disaster (26.4%), the 2008 financial crisis (12.4%), and the outbreak of COVID-19 (13.9%) has the S&P 500 index performed worse over two consecutive trading days than after Trump's tariff announcement.