The last few years have been good to borrowers. New homebuyers could lock in 30-year mortgages with interest rates as low as 3.4% last spring, provided they had excellent credit scores and a decent down payment.

Meanwhile, savers have been hurting, given interest rates on savings accounts, bonds and other safe-haven assets have been at historic lows.

It's all thanks to the Federal Reserve's massive bond-buying program, which has intentionally pushed down interest rates in an attempt to stimulate spending and more economic growth.