(Photo: Ken and Anne Dias Griffin)

The people who run hedge funds, as everyone knows, are tight-lipped. But even by the lockdown standards of the industry, Citadel Investment Group and its founder, Ken Griffin, stand out. He has his employees sign such strict nondisclosure agreements that one former executive deadpanned over the telephone, "I’m not allowed to even say the word Citadel to you."

Griffin has kept the internal workings of Citadel closed to all but a tiny inner circle, a feat made possible by the fact that the company is based in Chicago, away from the glare of the New York media. He rarely talks to the press and has bought the rights to photographs of himself and his wife to keep them out of circulation. "We zealously guard our private life," he said during a recent interview in New York, with his wife by his side.

In an age when private-money kings like the Blackstone Group’s Stephen Schwarzman and SAC Capital’s Steve Cohen have become pseudo-celebrities, Ken Griffin remains largely unknown despite sitting atop one of the most formidable companies in American finance. Citadel has ballooned into a $13.5 billion leviathan. (That’s $1.5 billion more than Cohen’s firm and half a billion dollars more than the fund run by George Soros, according to estimates.) On some days it trades as much as 3 percent of the volume on the Nasdaq and the New York Stock Exchange, making Griffin a very rich man, with an estimated net worth of $1.7 billion.

But as his industry emerges from one of the most lucrative periods of money-making in history and charges into an uncertain future, Griffin, 38, is reassessing. He is considering whether to take Citadel public in what would likely be the biggest stand-alone hedge fund initial public offering ever seen in the United States. At the same time, he is working aggressively to transform his company into a financial supermarket akin to Citigroup and Goldman Sachs. "We still have a lot of aspirations ahead of us," he says.

Such grand plans are symptomatic of what might be described as a hedge-fund-industry midlife crisis. A generation of swaggering yet press-shy financial barons has spent the past decade making billions of dollars—the rest of the world be damned. Now they’re waking up to a sobering realization: Nobody actually likes them. They are reviled in the public imagination for their secrecy and extravagant spending and resented by their peers on Wall Street for their huge paychecks. Each passing day, it seems, brings new calls for more regulation and better disclosure. At the same time, their jobs are getting more difficult. Intense competition has made it harder to generate the returns to justify their enormous fees.

It is in this climate that two kinds of hedge fund leaders have emerged: One type just wants to get rich and buy a Boeing 767 and a private island; the other harbors much grander ambitions, striving to rise above the industry’s frayed public image through philanthropy or politics. Griffin represents both.

Fundamentally, he’d just like to be left alone. He remains socially awkward and is clearly uncomfortable with the press; in our interview, he frequently turned to his glamorous wife, Anne Dias Griffin, 36, for reassurance.

But his great wealth has also pushed him into the limelight. Griffin has been mentioned as a possible candidate for political office in Illinois, a notion he dismisses. He and his wife also recently made a $19 million donation to the Art Institute of Chicago and purchased Jasper Johns’ painting False Start from Hollywood mogul David Geffen for $80 million, catapulting them into the top tier of American collectors.

Between them, they’ve joined the boards of the Art Institute of Chicago, Children’s Memorial Hospital, the Chicago Symphony Orchestra, and the Chicago Public Education Fund, among others. "We want to leave the city a better place than it was when we came to it," Griffin says.