Federal Reserve's Ben Bernanke aims
Federal Reserve chairman Ben Bernanke, in his bi-annual testimony to Congress, sought to reassure markets about plans for ending its policy of easy money.
Mr Bernanke said the end to easy money was not on a "preset course".
He defended the bank's transparency policy, saying "markets are beginning to understand our message and volatility has moderated".
His comments in May suggesting that the bank might end its purchase of bonds had led markets to fluctuate wildly.