Rolling out the central bank's aggressive new strategy at a virtual Jackson Hole symposium, Fed chief Jerome Powell said it would offset below-2% periods with higher inflation "for some time," and ensure employment doesn't fall short of its maximum level. Boeing Co BA.N rose 1.7% after the European Union Aviation Safety Agency announced plans to begin flight tests of its 737 MAX plane, a move viewed as a key milestone toward its return to service. Rate-sensitive bank stocks .SPXBK jumped 2.5% as the Fed's move steepened the U.S. Treasuries yield curve.