A small criminal percentage of people on Wall Street tarnish the reputation for a vast majority that are honest and hardworking, said FBI special agent David Chaves. But the small percentage of those who break the law, cheating honest Wall Street participants, must be identified and prosecuted so as to deter future market manipulation. The man in charge of the FBI team that led to the largest insider trading prosecution in recent history, putting behind bars the likes of former hedge fund manager Raj Rajaratnam and McKinsey partner Rajat Gupta, said initially the FBI had very little visibility into the...