The Mortgage Bankers Association (MBA) reported on Wednesday the mortgage application volume in the U.S. tumbled 11.9 percent in the week ended October 18, following a 0.5 percent gain in the previous week.

According to the report, refinance applications plunged 17.1 percent, while applications to purchase a home fell 3.6 percent.

Meanwhile, the average fixed 30-year mortgage rate increased to 4.02 percent from 3.92 percent.

“Interest rates continue to be volatile, with Brexit votes and ongoing trade negotiations swinging rates higher or lower on any given day.” said Mike Fratantoni, the MBA’s senior vice president and chief economist. “Borrowers with larger loans are the most sensitive to rate changes, and with rates climbing higher last week, the average size of a refinance loan application fell to its lowest level this year.”