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.

Fed chair Jerome Powell will deliver remarks at Jackson Hole on Friday. State Street's chief strategist lays out what investors should listen for.