New Delhi, July 29 -- WASHINGTON - When Kevin Warsh steps to the podium on Thursday afternoon, the options market will have done more to shape the preceding 24 hours of global trading than any word he has let slip. That is, by design or accident, precisely the position the new Federal Reserve chairman has put himself in.

Federal Reserve policymakers convened in Washington on Wednesday for the first day of their July meeting, with the rate decision expected Thursday afternoon. Warsh inherited a federal funds rate of 3.50 to 3.75 percent from Jerome Powell, and prediction markets are pricing roughly a 68 percent probability that he keeps rates at that range. The roughly 30 percent chance attached to a hike makes this the most uncertain Fed...