Weil on Finance: Goldman's Mysterious Trading Loss

``A complex bet in the foreign-exchange market backfired on Goldman Sachs Group Inc. during the third quarter, people familiar with the matter said. The previously undisclosed trading mishap played a part in a revenue slump that prompted senior executives to defend the firm's trading strategy." How big a part? Don't know. The article says: "It isn't clear how large the trade was or how long it was in place''