Adjustable rate mortgages are back.

After accounting for nearly 70 percent percent of all mortgages issued during the boom, ARMs vanished during the bust, totaling just 3 percent of the market in 2009. Now they make up 5 percent of all mortgages issued, and Freddie Mac predicts 10 percent by December.

Behind the comeback is a simple fact: ARMs are a great bargain right now. The most common ARM loan currently has a rate of 3.5 percent compared to 5 percent for a 30-year fixed-rate mortgage. Get the full story »