The outstanding supply of single-family MBS in the market fell slightly in the first quarter, but you have to go two paces to the right of the decimal point to see it. A new Inside MBS & ABS analysis indicates that outstanding MBS totaled $6.407 trillion as of the end of March. That was down 0.01 percent from the previous quarter, stalling a steady expansion of the market that took place in 2015. And with a modest 0.2 percent increase in total single-family mortgage debt outstanding, the modest contraction in MBS nudged...[Includes two data tables]