Mortgage Interest Rates One of the big factors underlying the market’s strength in recent years has been extraordinarily low interest rates, which have a tremendous effect on the ongoing, monthly cost of housing. In 2010, pundits almost universally predicted interest rates would rebound to 6% or higher, but instead rates dropped until hitting a low point in mid-2013 of about 3.5%. After fluctuating up and down a bit since, interest rates at the start of 2015 were somewhat below 4% - incredibly low by any historical standard.