The available supply of residential MBS grew marginally during the fourth quarter of last year as the agency market grew enough to offset the ongoing decline in outstanding non-agency MBS, according to a new analysis by Inside MBS & ABS. The supply of single-family agency MBS increased by $48.1 billion during the fourth quarter, a 0.9 percent increase over the three-month period. The Federal Reserve gobbled up all the increase and then some; its total agency MBS holdings rose by $91.6 billion during the fourth quarter, an 11.0 percent increase from the previous period. Mutual funds appeared to hold...[Includes two data charts]