Refinance demand plummeted last week, with applications dropping by a seasonally adjusted 20 percent from the week before and falling to their lowest level in four years.

Higher mortgage rates have been putting the squeeze on refinancing in recent months, with applications declining by 71 percent since rates started climbing in May, according to the Mortgage Bankers Association's Refinance Index.

Home purchase loans holding their own

At the same time, the runup in Further information: