Fed Chair Powell sparked a big rally as he signaled the central bank could cut rates in September in his remarks at the Jackson Hole policy symposium.

Federal Reserve Chair Jerome Powell has been under pressure from President Trump to lower the central bank's benchmark interest rate.

Minutes after the speech, investors pegged the chances of a quarter-point interest rate cut at 91%, up from a 75% chance assessed one day earlier, according to CME FedWatch Tool, a measure of market sentiment. Despite the market's positive reaction to Powell's speech, the Fed chair voiced a note of caution for the outlook for the U.S. economy.