The supply of outstanding single-family MBS in the market fell 0.6 percent during the third quarter of 2011, according to a new analysis by Inside MBS & ABS. There was a total of $6.544 trillion of single-family MBS outstanding at the end of September, the lowest level since the third quarter of 2007. Although MBS supplies have been declining steadily over the past four years, securitized loans actually represent a historically high 63.3 percent of total home loan debt outstanding as of the end of the third quarter. The steepest decline is in non-agency MBS, a...(Includes one data chart)