Average fixed mortgage rates moved slightly lower for the week. helping to spur ongoing refinance activity, according to Freddie Mac's recently released Primary Mortgage Market Survey® (PMMS®).

The 30-year fixed-rate mortgage (FRM) averaged 3.44 percent with an average 0.6 point for the week ending September 8, 2016, down from last week when it averaged 3.46 percent. A year ago at this time, the 30-year FRM averaged 3.90 percent.  

The 15-year FRM this week averaged 2.76 percent with an average 0.5 point, down from last week when it averaged 2.77 percent. A year ago at this time, the 15-year FRM averaged 3.10 percent.  

The 5-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) averaged 2.81 percent this week with an average 0.4 point, down from last week when it averaged 2.83 percent. A year ago, the 5-year ARM averaged 2.91 percent.

"The 30-year fixed-rate mortgage fell 2 basis points to 3.44 percent this week,” says Sean Becketti, chief economist, Freddie Mac. “As mortgage rates continue to range between 3.41 and 3.48 percent, many are taking advantage of the historically low rates by refinancing. Since the Brexit vote, the refinance share of mortgage activity has remained above 60 percent."