After a huge drop in mortgage interest rates, American borrowers rushed to take advantage of the situation by applying for refinance loans.

Total mortgage application volume rose 18.6% last week, according to the Mortgage Bankers Association, and 28% from the year before. That gain was largely due to a 39% surge in refinance loan requests. Home purchase mortgage applications only rose 3%. The refinance share of all applications shot up to 47.4%, from 40.4% a week earlier.