Commercial banks and thrifts added $12.2 billion of agency single-family MBS to their investment portfolios during the fourth quarter of 2014, according to a new Inside MBS & ABS ranking and analysis of call-report data. Banks and thrifts held $1.539 trillion of MBS on their books at the end of last year, a slight 0.3 percent increase from the third quarter. Bank/thrift holdings were up 2.2 percent from the end of 2013. Growth in agency mortgage securities was...[Includes two data charts]