Originations of non-agency jumbo mortgages declined in the first quarter of 2018 at a number of banks that provide early disclosures about their business. Officials cited seasonal factors for the lower volume and suggested that production will bounce back in the second quarter. First Republic Bank, the largest of the four banks in terms of jumbo production, had $2.33 billion in total originations in the first quarter. Jumbos tend to account for more than 90.0 percent of its total production ...