Several top-tier commercial banks increased their holdings of first-lien mortgages during the first quarter of 2014, according to a new ranking and analysis by Inside Nonconforming Markets. The growing portfolios were largely due to jumbo mortgages along with some conforming loans. Banks and thrifts held $1.74 trillion in first-lien mortgages in portfolio at the end of the first quarter of 2014, down 0.7 percent from the previous quarter ... [Includes one data chart]