The Fed has not raised interest rates since 2006, and for the last seven years has expanded the boundaries of central bank activism with more than $3 trillion in asset purchases and near-zero interest rate. Conservatives within the central bank and many Republicans in Congress argue that the Fed under Yellen, an Obama appointee with strongly stated concerns about the damage the financial crisis did to working families, is out of step with improvements in the U.S. economy, and lawmakers will likely press for details on when policy will change, which would as an effect have market volatility.
USD is broadly higher against its major rivals. Euro is currently being traded at 1.13 handle, Sterling is around 1,.5440 area, while Aussie is few points above 0.7740 level.