A potential “attempt to influence the Fed so directly” by announcing a successor to Jerome Powell well before his term expires “does not set well with investors,” notes one analyst.

The dollar slide has snowballed since Trump's trade war unfolded in April amid worries about foreign investor flight and uncertainty about U.S. policymaking. A revival of Europe's economic outlook has been the flipside, spurred by a ratcheting up of regional defense spending and Germany's dramatic fiscal boost.

President Donald Trump called on lawmakers to work over Fed Chair Jerome Powell for keeping interest rates elevated. In the first of two scheduled hearings on central bank policy this week, GOP Congress members left their pipes and brass knuckles at home.