Real estate investment trusts that specialize in the MBS market held $261.0 billion of mortgage securities in their portfolios at the end of March, according to a new Inside MBS & ABS analysis. That was down 1.4 percent from the end of the fourth quarter. REITs have been de-leveraging and scaling back their MBS holdings since the third quarter of 2012, when the Federal Reserve began its massive spending spree in the agency MBS market. A few REITs began rebuilding...[Includes one data chart]