Standard & Poors is defending its status as the top rating service in the non-agency MBS market through the first half of 2013, having put its stamp on 39.0 percent of the growing market, according to a new Inside MBS & ABS ranking. S&P has been the top non-agency MBS rating agency over the years but saw DBRS capture the title in 2012 with 54.8 percent of rated transactions. The non-agency ratings business has become significantly more fragmented than it was before the financial collapse, when S&P often rated more than 90.0 percent of the deals that came to market. Both Fitch and Kroll Ratings are...[Includes two data charts]