U.S. prosecutors expect more arrests in their rapidly expanding investigation into insider trading by hedge funds. After arrests last month in connection with billionaire Raj Rajaratnam and his Galleon Group, the Justice Department charged 14 more people with insider trading. They include corporate insiders, hedge fund executives and lawyers. Federal prosecutor Preet Bharara said the investigation is continuing. He had a message for those engaging in insider trading: "I urge you to come knocking on our door before we come knocking on yours."