G20 police question a suspected rogue trader at Swiss bank UBS for earlier this week . Credit rating agency Swiss bank UBS says it is reviewing UBS for a possible downgrade . It is thought that he may accidentally have left the Swiss franc vs U.S. dollar side of the equation uncovered and got stung when the Swiss national bank intervened to defend the franc in early September . Swiss bank UBS itself reported the rogue trader to police , officers say . Greek media name the arrested man as Kweku Adoboli .
G20 police question a suspected rogue trader at Swiss bank UBS for earlier this week . Credit rating agency Swiss bank UBS says it is reviewing UBS for a possible downgrade . Swiss bank UBS itself reported the rogue trader to police , officers say . Greek media name the arrested man as Kweku Adoboli .