Threadneedle investigated by police over $150m trading fraud A junior trader, who worked at the company's investment arm, was dismissed after attempting the rogue trade, thought to have been worth about $150m and alleged to be linked to Argentine warrants. Threadneedle, which is now owned by US financial services group Ameriprise, said in a statement: "In August 2011, our systems stopped a suspicious attempted trade. The matter was immediately reported to the authorities and the individual involved was subsequently dismissed. In recent months the financial services industry has been beset with rogue trading scandals that have hit some of the biggest names in the City. Warren Buffet's adage about seeing who is swimming naked - only when the tide goes out - seems particularly apt when it comes to the number of frauds committed since the financial crisis began. Kweku Adoboli, the former UBS trader last month denied charges of fraud and false accounting after allegedly causing the largest unauthorised trading loss in British history worth $2bn. He is expected to stand trial this year. Last week, the regulator working with the Serious Organised Crime Agency arrested a trader at Legal & General Investment Management, one of the UK's largest investment groups, in connection with the FSA's biggest probe into insider trading. He was the ninth man arrested over a two-year period.