Jules Kroll sensed opportunity. In the wake of the 2008 financial collapse, the reputations of the Big Three credit-rating companies lay in tatters. Standard & Poor's, Moody's Investors Service, and Fitch Ratings had all blessed various mortgage-backed securities with their highest ratings, despite the often shaky subprime loans underlying the securities. Kroll, who made his mark as a financial crimes private investigator, with offices in more than 15 countries, reckoned he could come up with a better way.

"There was enormous disappointment in the country about the way the rating agencies had behaved," Kroll says. "They really let the country down."

A man with a nose for ferreting out corruption, Kroll, 74, pocketed more than US$100 million when he sold his corporate detective firm, Kroll Associates, to Marsh & McLennan for $1.9 billion in 2004. He'd hunted down billions of dollars of assets concealed by Saddam Hussein, Ferdinand Marcos, Jean-Claude Duvalier, and other dictators. With the ratings business, Kroll thought he recognized a lucrative Act 2. He launched Kroll Bond Rating Agency in 2010.