Citigroup, of course, isn’t just a bank; it’s a multinational colossus, with 200 million customers in more than 100 countries. Its fingers are in every ­financial-services pie—banks, credit cards, brokerages, investment banking, and hedge funds. It is less a company than a collection of city-states. The glass-half-full way of looking at Citi is to see it as “a company that could not be created today at any price that would be rational,” as Michael Klein, Citi’s outgoing chairman of institutional clients, describes it.

The glass-half-empty view—the prevailing one on Wall Street—is that Citi is unmanageable in its current form. And it is this mess that Pandit must somehow unravel.

Managing Citi at a time like this requires many qualities, but optimism must surely count among them. In person, Pandit is cordial, supremely confident, and transparent up to a point, though he reverts to hostile-witness mode when asked about his private life, acting more like the hedge fund manager he recently was than the head of an immense publicly held company. One longtime associate tells me that he has known Pandit for many years but has never had dinner with him or been to his home, where Pandit lives with his wife and two adolescent children. Pandit recently bought a sprawling apartment on Central Park West that once belonged to the late actor Tony Randall.

Pandit is one of the most prominent Asians in corporate America, an emblematic Indian American success story. His hometown is not the cosmopolitan coastal city of Mumbai, as is commonly and incorrectly reported in the Western media, but Nagpur, a community farther east. It is a kind of Indian Middletown, located near the geographic center of the subcontinent. His father, now retired, was a pharmaceutical executive. His family name is of Hindu Kashmiri extraction—derived from the Hindi word for pundit. Nagpur is hardly the Paris of the subcontinent. It’s a market town of about 2.5 million people and an overnight train ride from Mumbai. During the British Raj, Nagpur became a center of the noncooperation movement against British rule. More recently, it has become a major manufacturing center.

Just like a provincial American city, Nagpur had little to offer its ambitious youth. A European diplomat based in New Delhi tells me that even when such towns grow richer, they often remain culturally stagnant. “There is no orchestra, no theater, no rock bands. Boredom is the chief trouble of India.”

But, he adds, Pandit didn’t stay long enough to experience much of that. “He got to America when he was 16 and stayed.”

That was 1973, when Pandit was admitted to Columbia University to study engineering—a typical, if precocious, career path for upwardly mobile young Indians at the time. He charged through college in three years. Pandit downplays his youthful brainpower, perhaps anxious to avoid being labeled a geek. He says, for instance, that he cracked the books during the summer because it was hard for foreign students to get summer jobs.

For Pandit, Columbia’s academic fare was far more palatable than a traditional Indian education. He gravitated toward economics and found the numbers-meets-strategy approach that would come to frame his career. “I found economics was an interesting juncture,” he says, “somewhere between the philosophical ways of looking at the world versus the precise engineering perspective. It was a way to blend both views, which I found fascinating.”

He received a master’s degree in engineering and then began studying finance. In 1982, he accepted a teaching position at Indiana University, in Bloomington, while completing his doctoral dissertation, “Asset Prices in a Heterogeneous Consumer Economy.” According to the abstract, his paper “examines the properties of asset prices in a multi-consumer, dynamic economy under uncertainty.” It sounds difficult, and it is, even by doctoral-dissertation standards. But it would define the playing field for Pandit once he arrived on Wall Street.

The Indiana campus was a far cry from the urban landscape of New York. “He was an excellent teacher, but being from India and New York City, he felt that maybe Bloomington was a little too small,” recalls Robert Klemkowski, who headed the business school’s finance department and hired Pandit.

While at Indiana, Pandit worked on a project for Morgan Stanley, and he was soon offered a job at the investment bank. Morgan Stanley was a partnership then and hired just 20 new M.B.A.’s each year. Its total head count, a mere 2,500, was a fraction of what it is today. Pandit began at the bottom of the ladder and moved steadily up the rungs, achieving a reputation as a cheerful, diligent, and uncomplaining worker bee. By the late 1980s, he was already performing impressively in Morgan Stanley’s capital markets division. It was a training ground for future leaders at the investment bank—former chairman Dick Fisher followed that career path as well—and Pandit was a steady, if not conspicuous, performer.