Christine Lagarde, president of European Central Bank, at a news conference on Thursday. The bank lowered its key rate a quarter point to 2.25 percent.
A day after recording its best gain since 2008, the S&P 500 fell 3.5 percent on Thursday, showing that fears about tariffs hampering economic growth were still alive.
The S&P 500 slipped, as trade hostilities continued to heat up between Washington and Beijing. Stocks in Europe and Asia had soared earlier, after President Trump paused some tariffs.