Black-Scholes didn't work; trillions of dollars' worth of securities may have been priced without regard to the possibility of crashes and panics. But until very recently, no one has bitched and moaned about this problem too loudly. Lay folk might harbor private misgivings about the clergy, but as lay folk, they are reluctant to express them. Now, however, as the subprime market unravels, the beginnings of a revolt against the church seem to be taking shape.

One of the revolt's leaders is Nassim Nicholas Taleb, the bestselling author of The Black Swan and Fooled by Randomness and a former trader of currency options for a big French bank. Taleb can precisely date the origin of his own personal gripe with Black-Scholes: September 22, 1985. On that day, central bankers from Japan, France, Germany, Britain, and the United States announced their intention to torpedo the U.S. dollar—to reduce its value in relation to the other countries' currencies. Every day, Taleb received a list of his trading positions from his firm and a matrix describing his risks. The matrix told him how much money he stood to make or lose, given various currency fluctuations. That September 22, when the central bankers announced their plan to lower the dollar's value, he made money but didn't know it. "I didn't know what my position was," he says, "because the movement was outside the matrix they'd given me." The French bank's risk-analysis program assumed that a currency crash of this magnitude would occur once in several million years and therefore wasn't worth considering.

Taleb made a killing that day, but it wasn't thanks to a grand plan and it wasn't happy money. "People in dark suits started coming from Paris," he says. "They said that the only way I could have made that much was to have taken far too much risk." But he hadn't. They had simply failed to account for the true nature of risk in financial markets. "Then I started looking at the history of markets," he says. "And I saw that these sorts of things happened all the time." Taleb became obsessed with the way prices in the options market, based on the famous Black-Scholes model, underestimated the risk of extreme and rare events. He set up his trading to profit from such events by buying up disaster insurance that would, according to Black-Scholes, be considered overpriced. When October 19, 1987, arrived, he was prepared. "Ninety-seven percent of all the returns I ever made as a trader, I made on that day," he says.

THE SOLUTION

In the past two years, Taleb has co-authored a pair of papers that have appeared in the sort of academic journals that originally published the Black-Scholes model. He and his co-author attack the model head-on in its own language (math), and as much as call for a retraction of the Nobel Prize awarded to Myron Scholes and Robert Merton for their work in creating the model. "This is what I'm saying to Merton and Scholes," Taleb says. "You guys are just parasites. You're not bringing anything useful to the market. You are lecturing birds on how to fly. You're watching them fly. And then you're taking credit for it."