If there’s a singular image of the American economy in action, it’s perhaps the frenzied floor of the New York Stock Exchange. The opening bell rings, traders shout and stock prices rise and fall. It’s familiar territory for William Johnston. Johnston is the former head of the exchange. He spoke at Samford University Thursday. As Johnston finished his tenure at the exchange in late 2001, the financial world was rocked by accounting scandals at Enron and Worldcom. WBHM’s Andrew Yeager asked if there are any similarities between that market turmoil and what we’re seeing today.