A romance with risk that brought on a panic

“How are you making money on side bets? What else are you guys doing to make money here?” Mr. Corzine asked enthusiastically, his eyes widening, the broker recalled. The new chief executive grabbed a seat and spent an hour questioning Mr. Monley as other top executives from New York hovered impatiently nearby.

Although Mr. Corzine had been a United States senator, governor of New Jersey, co-head of Goldman Sachs and a confidant of leaders in Washington and Wall Street, he was at heart a trader, willing to gamble for a rich payoff.

Dozens of interviews reveal that Mr. Corzine played a much larger, hands-on role in the firm’s high-stakes risk-taking than has previously been known.