Commercial banks and thrifts reported $153.1 billion in single-family home loan sales by their mortgage-banking operations during the fourth quarter of 2015, a steep 24.8 percent drop from the previous quarter. For the year, secondary market activity was up from 2014 but still relatively sluggish. Depository institution mortgage-banking shops sold $721.2 billion of home mortgages last year, a 19.9 percent increase from 2014. But 2015 was the ... [Includes one data chart]