Total nationwide mortgage debt rose $120 billion from the fourth quarter of 2015 to the first quarter of 2016 for a total of $8.37 trillion. When taking into account mortgage debt, HELOCs, student, auto and credit card debt, the sum total is $12.25 trillion. The Mortgage Bankers Association (MBA) reports that its Market Composite Index, a measure of total mortgage application volume, rose by 2.3% in the latest week, while the refinance index edged higher by 0.4%. The big push came from the purchase index, rising 5%.