Stock indexes dropped and bond yields rose as Fed Chairman Kevin Warsh concluded his news conference. Traders appear to be coming out of the press conference expecting more rate hikes than they did prior to it starting.

"The hawkish tone of the press conference" drove markets lower, said Jeff Schulze, head investment strategist at the Franklin Templeton Institute. "Warsh's press conference closely echoed the hawkish tone of his Jackson Hole remarks, framing the hike as evidence that the committee is backing its words with action on returning inflation to target."