The federal government's gradual pullback as an investor in the MBS market is beginning to open more space for commercial banks and other private investors. Commercial banks increased their investment in residential MBS by a solid 6.5 percent during the first quarter, pushing their combined holdings to a record $1.311 trillion. That represented about 20.0 percent of an overall MBS market that has been shrinking since the third quarter of 2009. Bank holdings of residential MBS were up 14.2 percent from the first quarter of last year. Through the U.S. Treasury, the Federal Reserve and the retained holdings of Fannie Mae and Freddie Mac, the federal government held... [Includes two data charts]