Investment bankers used to be known as respectful of their clients, loyal to their firms, and chary of the financial system that allowed them to prosper. What happened? From his prestigious Wall Street perches at Goldman Sachs and Morgan Stanley, Jonathan A. Knee witnessed firsthand the lavish deal-making of the freewheeling nineties, when bankers rode the wave of the Internet economy, often by devil-may-care means. By the turn of the twenty-first century, the bubble burst and the industry was in free fall. Told with biting humor and unflinching honesty, populated with power players,...