Credit unions held a total of $107.1 billion of MBS in their portfolios at the end of the first quarter of 2013, according to a new Inside MBS & ABS analysis and ranking of call report data. That was up 4.9 percent from the previous period, a relatively strong increase in a market where the supply of MBS outstanding has barely budged and the Federal Reserve represents a huge competitor for new issuance. Compared to a year ago, credit union MBS holdings were up 10.9 percent, while the total MBS market actually declined by 1.4 percent. Credit unions for the most part have ignored...[Includes one data chart]