At Galleon, this was known as “getting an edge.” The analyst or portfolio manager with the best read on a company was called the “axe” on that stock.

Once the flow of money created an obligation, Rajaratnam began asking for financial details about companies that Kumar advised.

Soon, Kumar was breaking both Mc Kinsey’s confidentiality rules and the securities laws that forbid such exchanges.

“Lots of people set up offshore companies,” Rajaratnam said, trying to alleviate Kumar’s squeamishness.

Pulling off the subterfuge required a false mailing address, signatures obtained under false pretenses, backdated investment documents, and phony doctor’s bills.

Mc Kinsey executives, in an attempt to cash in on the explosive growth of hedge funds, had recently sent Rajaratnam several e-mails proposing that Galleon hire the company to provide expert advice. Leaving the charity event, Kumar expressed annoyance about the unanswered e-mails, he later recalled. “I’d much rather have as a consultant than Mc Kinsey,” he explained.

“And I am willing to pay you half a million dollars a year.” Kumar replied that Mc Kinsey forbade outside consulting, but Rajaratnam persisted, appealing to Kumar’s pride: “You work very, very hard, you travel a lot, you are underpaid.They had known each other since the early eighties, when, as recent immigrants, they were classmates at the Wharton School of Business, in Philadelphia.Their friendship, intermittent over the years, was based on self-interest rather than on intimacy.Rajaratnam’s goal was to be running a ten-billion-dollar fund by the end of 2009.In seducing Kumar, he made a valuable addition to the network that he had built up over the years.By the mid-aughts, hedge funds accounted for nearly half of all stock trades, and there was ferocious competition for wealthy investors and the business of investment banks.