A slowdown in volume appears to be catching up to the subprime MBS market. While volume rose during the first quarter of the year, it didn’t grow at the gangbuster pace of the previous two years. According to data compiled by the Inside Mortgage Finance MBS Database, subprime MBS issuance through the end of March rose at a solid 19.3 percent clip, to $123.28 billion, on a year-to-year basis. Significantly, at its current pace,… [One data table included]