Aggregators of jumbo mortgages have seen margins on their business decline as competition increases for the loans. Redwood Trust had $9.0 million in net income from its residential mortgage banking segment in the second quarter of 2018, down from $21.0 million in the previous period. Officials said the decline was due to lower margins during the second quarter. The real estate investment trust didn’t disclose specific figures other than to note that during the second quarter ...