When credit rating agencies gave structured credit products ratings that appeared to be the same as those given to traditional securities, investors assumed that they had received the same level of scrutiny and carried an equivalent risk level. In fact, the analysis was often based on models with faulty assumptions (such as continuously rising housing prices) and greatly underestimated the actual risk. Since the model and assumptions used to evaluate structured credit products were not disclosed, investors were unable to evaluate properly either the securities or the ratings given to them.