Standard & Poor’s has changed its rating criteria for two of the most popular types of alternative loans in the market, second-lien home-equity lines of credit and option adjustable-rate mortgages. With regard to HELOCs, S&P offered some good news. The rating agency said that an analysis of loans from a variety of originators led to the conclusion that the 100 percent loss severity estimate it applied to all loans, regardless of CLTV, was “overly