U.S. futures industry investigators are looking into why Iowa-based collapsed brokerage PFGBest used a tiny accounting firm that appears to be operating from inside a suburban Chicago home to audit its books, according to a person familiar with the matter. Experts said the use of such an auditor should have been a red flag to regulators of a futures brokerage with more than $500 million in assets and several hundred employees across the United States as well as in Shanghai and Canada
