Merck ( MRK ) fell 3.13% to $45.53. The Federal Reserve announced after its two-day meeting that it will maintain its current pace of buying $85 billion worth of bonds, and it will lower or raise the amount of purchases as labor market and inflation conditions evolve. The Mortgage Bankers Association, or MBA, reported today in its Weekly Application Survey that the Market Composite Index, which measures mortgage loan application volume, increased a seasonally adjusted 1.8% week-over-week for the week ended April 26.