Alternative to Traditional Mortgage Securitization Gathers Momentum A new breed of synthetic mortgage securitization technique is giving some of the largest lenders in the U.S. a new outlet for their production. Bank of America late last year set up a Real Estate Synthetic Investment Securities structure that has issued five transactions so far in 2003. The issued securities total $186 million and roughly represent credit support for a total of $80.4 billion of prime-grade mortgages