The recent disclosure of a multi-billion dollar trading loss at JPMorgan Chase reminds us again of the challenge and complexity of risk management, the subject of our June 2012 HBR article, “Managing Risks: A New Framework.” Many people, including quite a few U.S. legislators and regulators, believe that risks can be managed by establishing and following rules, standards and guidelines. But for certain categories of risk, this is a false and dangerous assumption.