'Investors may be getting used to Wall Street scandals, but a mass arrest of foreign exchange professionals is still jangling a few nerves. The Federal Bureau of Investigation arrested about 48 currency traders who are believed to have defrauded retail clients out of millions of dollars, Reuters reported. The FBI led the men out in handcuffs last night in Manhattan and several East Coast cities last night, according to reports. Charges against traders at more than a dozen firms are expected to be announced today, The Wall Street Journal said. In one case, employees at J.P. Morgan Chase (JPM, news, msgs) and UBS AG were accused of arranging deals that where their firms lost money, but firms who were customers made money. The workers then took kickbacks from the customer firms, the paper said. An employee of Madison Deane and Associates told Reuters that FBI agents stormed its Manhattan office with guns drawn. The employee said an agent told workers that $4 million was stolen from clients and money was taken out of individual retirement accounts, according to a wire service account'.