The Wall Street Mind: Anxious...

Even if investment banks find new ways to make money after the previous methods ended in a crash and scandal--their age-old pattern of behavior--many wonder if any newfangled proposition can rival mortgage securitization. It just made so much money. "We always seem to find the next thing; that's part of our DNA. But nothing else feels as large as that. It was just so enormous," says one executive.

There is a deeper worry: that the only way banks can make the megaprofits they need to support their vast staffs and infrastructure is in operations that are at best opaque and impossible for outsiders to understand and at worst unethical and possibly illegal. Wall Street's history is that, at the peak of bubbles, sensing that the end is coming and the profit opportunity disappearing, it degenerates into shocking behavior.