US banking giant JPMorgan Chase on Thursday posted better than expected third quarter earnings, with profits falling only slightly thanks to a $1.9 billion risk accounting revision. Acknowledging a \"challenging investment banking and capital markets environment,\" the bank reported a profit of $4.3 billion, down four percent from the same quarter in the previous year. The report could assuage some concerns about the health of US banks amid a renewed financial crisis in Europe. \"All things considered, we believe the firm\'s returns were reasonable given the current environment,\" said company CEO Jamie Dimon. \"Our shareholders should rest assured that we are being extremely cautious while navigating through this challenging economic environment.\" The bank\'s earnings were swollen by a $1.9 billion benefit gleaned from a \"debit valuation adjustment,\" one accounting tool used to calculate risk to a bank and its portfolio.