David Robin, an interest rate strategist at Newedge LLC, said Fed policymakers were surprised by how quickly interest rates rose. They worried that rates would rise even more, and jeopardize economic growth, if they actually reduced the bond-buying."The Fed knows once they started to move," the market reaction "would be almost impossible to control," Robin said. â¿¿ Paul Wiseman, AP Economics Writer _____ Follow Paul Wiseman on Twitter at https://Twitter.com/PaulWisemanAP . Follow Chris Rugaber at https://Twitter.com/ChrisRugaber .