( CNN ) -- UBS announced Thursday that rogue trading by one of its investment bank traders had cost the Swiss banking giant a staggering $ 2 billion . But while the loss would potentially be among the largest costs ever to a bank in unauthorized trading , it is far from the first . The UBS scandal revealed Thursday is the latest in a long list of unauthorized trades that have cost banks billions of dollars . From foreign currency trading to speculating on futures derivatives , a number of individual rogue traders have destabilized and even caused the collapse of their banks through unauthorized trades in the past twenty years alone . Jerome Kerviel -- $ 6 billion , Societe Generale . In January 2008 , French trader Kerviel was arrested in Paris and accused of committing massive fraud that cost Societe Generale Bank nearly $ 6 billion . Kerviel was involved in the practice of arbitrage at the bank , buying a portfolio of financial instruments -- European index futures in Kerviel 's case -- in one market and selling a similar offsetting portfolio at the same time with a different value in order to minimize risk . Kerviel 's offsetting portfolio , however , was `` fictitious , '' according to the bank , meaning Kerviel had in effect made an unhedged bet of a staggering $ 60 billion of Societe Generale 's money on European futures without the bank 's knowledge -- a bet that end up costing the bank roughly $ 6 billion . 33-year-old Kerviel , who was sentenced to three years in prison last year , insisted he was n't the only one doing this and that his bosses knew of and condoned his behavior while at the bank . `` During three years these managers earned colossal amounts of money out of bonuses based on the ever growing results that I was making for the bank , '' he said . Yasuo Hamanaka -- $ 2.6 billion , Sumitomo Corporation . Hamanaka was sent to prison for eight years in 1997 for fraud and forgery in the global copper market . The copper trader 's unauthorized deals ended up costing Japan 's Sumitomo Corporation $ 2.6 billion . Nicknamed `` Mr. Five Percent '' in reference to the amount of the global copper market he was once estimated to control , Hamanaka was accused for years of price-fixing in order to generate exorbitant profits for Sumitomo . The one-time king of the copper market would have Sumitomo buy huge quantities of copper and store it for awhile in order to create an artificial shortage of the precious metal , thus driving up demand , before releasing smaller amounts of copper on commodities markets at extremely high prices . The decade-long scheme fell apart in 1996 , and in 1998 Sumitomo paid $ 150 million to regulators while refusing to admit or deny if the corporation knew about or condoned the actions of its rogue trader . Nick Leeson -- $ 1.3 billion , Barings Bank . The British trader 's losses of over a billion dollars singlehandedly brought down Barings Bank , the former personal bank to Britain 's Queen , in 1995 . At first Leeson , a star trader in Barings ' Singapore branch , made huge profits in the early nineties by speculating on futures derivatives for the bank . A loophole in Barings ' oversight system allowed Leeson to settle his own deals , meaning he could set up fake accounts for non-existent clients -- and as his luck began to run out , this is precisely what he did , masking huge losses by placing them in a single secret account while making increasingly risky bets in an attempt to recoup the losses . In January 1995 , Leeson bet that the Japanese Nikkei index would rise after performing poorly the previous year , but his timing could not have been worse -- the Kobe earthquake on January 17th , the worst in Japan in 70 years , sent stock prices plummeting . His big bet having failed , Leeson attempted to flee back to the UK but was arrested and extradited back to Singapore , where he was sentenced to six and a half years in prison for financial misrepresentation . He served three before being released . The $ 1.3 billion in liabilities Leeson ran up wiped out 233-year-old Barings ' capital and reserves , and the bank collapsed . John Rusnak -- $ 700 million , Allfirst / Allied Irish Bank . In February 2002 , AIB executives called the FBI after discovering that both roughly $ 700 million and 37-year-old trader John Rusnak had gone missing from work . Working for AIB 's Allfirst subsidiary in Baltimore , Maryland since 1993 , the foreign currency trader worked under the radar for nearly a decade , betting mostly on the price of the Japanese yen and racking up hundreds of millions of dollars in small losses that he attempted to hide in fabricated options contracts . Part of the reason Rusnak was able to perpetrate such massive fraud was poor supervision and financial controls at AIB -- although Rusnak 's trading limit was $ 2.5 million , by 2002 he was betting up to $ 7.5 billion ( 3,000 times his limit ) of AIB 's money on currency movements , according to the Financial Times . AIB sold its scandal-hit Allfirst subsidiary in late 2002 , and Rusnak served over seven years in prison .
Jerome Kerviel cost Societe Generale $ 6 billion in unauthorized trading by 2008 . John Rusnak lost over $ 700 million in currency trading at Allfirst bank by 2002 . Nick Leeson 's $ 1.3 billion in losses brought down Britain 's Barings Bank in 1995 .