Financial markets are taking in a collective breath ahead of Jerome Powell's eighth and final keynote Jackson Hole speech as Federal Reserve Chair. If the moves following his last seven are any guide,

The president's latest attack comes as Powell is scheduled to deliver remarks at the Fed's annual conference in Jackson Hole, WY, on Friday.

Jerome Powell’s speech at the Federal Reserve’s August summit in Jackson Hole, Wyoming, is always a high-stakes moment. This year, the central bank’s chair takes the podium under fire – facing fierce attacks from US President Donald Trump and a growing insurgency within his own institution.