Holdings of residential first-lien mortgages by banks and thrifts increased again in the third quarter of 2017, according to a new ranking and analysis by Inside Nonconforming Markets. Banks and thrifts held first liens with a total unpaid principal balance of $1.99 trillion as of the end of the third quarter, up 1.1 percent from the previous quarter and a 3.3 percent increase from a year ago. First-lien holdings are dominated by three big banks: Wells Fargo ... [Includes one data chart]