Steady growth in the outstanding supply of agency single-family MBS offset the ongoing decline in non-agency MBS in the fourth quarter of 2014, according to a new Inside MBS & ABS analysis. Outstanding single-family MBS edged up 0.1 percent from the third quarter to finish the year at $6.357 trillion. Although that was the third straight quarterly gain, the yearend total still came up 0.6 percent short of the total outstanding at the end of 2013 ... [Includes one data chart]