The freefall in new non-agency MBS issuance during early 2008 yielded sharp swings in market share for the major rating services – although volume was so low that the results don’t necessarily point to any significant change in the market. Standard & Poor’s, long the industry leader in non-agency MBS, saw its share of new ratings drop from 93.6 percent in 2007 to just 54.1... [Includes two charts]