Good Question: Why Are Mortgages Sold?After mortgage banker Alex Stenback of<a href="http://www.behindthemortgage.com"> Alerus Mortgage</a> helps people buy a new home, he sells off the mortgage. “We sell everything that we do here,” Stenback said. “When we sell them, it’s one by one.” About 80 percent of home loans are eligible to be sold. Stenback says it can happen for a couple of reasons. “One is there is $10 trillion in outstanding mortgages right now in the country and there's simply not enough deposits in all the banks to make that many mortgages," he said.