The rapid increase in securitization of option ARMs and the favorable performance characteristics of these securities make them an attractive investment opportunity in today’s market, according to analysts at Bear Stearns. Issuance of option ARM mortgage securities in the non-agency MBS market has grown significantly over the last four quarters, noted Dale Westhoff, a Bear Stearns senior managing director, during a conference call this week. Securitization of option ARMs has grown from under $5 billion…