Goldman Sachs Group CEO Lloyd C. Blankfein

Goldman Sachs Group CEO Lloyd C. Blankfein

Scott Eells/Bloomberg

Goldman Sachs Group Inc. Chief Executive Officer Lloyd C. Blankfein is facing a prolonged slump in fixed-income trading as he seeks to boost return on equity, which has been less than 12 percent for four straight years after topping 30 percent before the financial crisis.