27 June 2013, by Ruth Mantell - Washington (marketwatch)

Following news that the Federal Reserve could start tapering bond purchases this year, mortgage rates soared over the past week, with the popular 30-year fixed-rate mortgage rate hitting the highest level in almost two years, according to data released Thursday.

The average rate for the 30-year fixed-rate mortgage rose to 4.46% in the week ending June 27, the highest rate since July 2011 — up from 3.93% in the prior week, Freddie Mac said in its weekly report.

That gain of 53 basis points is the largest weekly change since 1987. A year ago, the 30-year rate averaged 3.66%.

Despite recent rate gains, housing affordability remains relatively high and economists say an improving economy should help the housing market continue to rebound this year.