The volume of interest-only mortgages originated in 2015 increased compared with the previous year, according to a new ranking by Inside Nonconforming Markets. IOs appear to be the most common type of non-qualified mortgage currently being offered by lenders. A group of 12 lenders originated $29.56 billion in IOs in 2015, up 8.5 percent compared with the previous year. The loans fell outside of QM standards set by the Consumer Financial ... [Includes one data chart]