Issuance of subprime securities soared to new heights in 2004, a new Inside B&C Lending analysis and ranking reveals. In a performance that confounded many pundits – who expected volume to fall or hold steady last year amid a waning refinance wave – subprime MBS volume rose 98.2 percent, to a record $401.46 billion, on a year-to-year basis in 2004. (See next page.) More than half of the year’s total volume, $235.78 billion, was…