Real estate investment trusts that focus on the MBS market saw the value of their holdings slump again during the volatile second quarter of 2015. Top mortgage REITs reported a fair market value of $249.10 billion for their single-family MBS holdings as of the end of June. That was down 5.6 percent from the previous quarter, and it was the group’s lowest MBS portfolio valuation since the fourth quarter of 2011. The decline came...[Includes one data table]