Yellen hints rate hike is possible around mid-2015

Taper tantrum: The Fed altered its guidance on the likely path of interest rates, putting less weight on the unemployment rate as a signpost for when rate increases will start. The bond-buying program will be cut by a further $10 billion, to $55 billion a month.

U.S. stocks and bonds fell as the Federal Reserve's latest policy statement raised jitters about the prospect of interest rates rising sooner than some in the market have been anticipating.