As interest rates rise, U.S. homeowners are losing their incentive to refinance.

Applications to refinance a home loan fell 4.5 percent last week, according to data released Wednesday from the Mortgage Bankers Association.

That sent the refinancing share of total mortgage activity to 38.5 percent, the lowest since September 2008.

Meanwhile, the average 30-year fixed rate for conventional mortgages, at 4.68 percent, held near its highest level in four years.

That’s not deterring buyers much yet: The MBA’s purchase index of mortgage applications rose 1.4 percent last week and remains near a seven-year high.