How `Mr Copper' became the world's biggest fraud

Yasuo Hamanaka was not best known for charisma. With his steel- rimmed glasses and grey flannel suits, he was a generic senior Japanese salaryman. Nor do non-ferrous metals sound, on the face of it, the most glamorous of commodities. But his confidence and his power to move this market were unmatched. So, it turns out, was his colossal dishonesty.

We have had Nick Leeson, the trader who brought down Barings. Then came Toshihide Iguchi, a New York-based dealer awaiting sentence. Now the league table of rogue traders is topped by a new name. Mr Hamanaka, one of the world's most feared and respected copper traders, has left the mighty global Sumitomo Corporation trading company with losses totalling $1.8bn (pounds 1.2bn). The Serious Fraud Office in London yesterday announced an urgent investigation into Sumitomo's affairs.

Just a few years ago, Mr Hamanaka was a business hero. The Sumitomo annual report of 1991 gave its star trader a double page spread of his own, complete with glossy portraits and adulatory profile. He is quoted as saying that the preeminent position of Sumitomo Corporation in copper trading is attributable to "expertise in risk management". At this point, according to the latest accusations against him, Mr Hamanaka had been carrying on his illegal trade, completely undetected, for five years.

Leeson ($1.4bn) and Iguchi ($1.1bn) became notorious only after the event, when the details of their private lives were picked over with equal relish by the British tabloids and their oriental equivalent, Japan's weekly magazines. But in the world of copper trading Mr Hamanaka has long been a legend.

Once, the story goes, a speculator in one London market became so frustrated with his financial heft that he punched out the window of the public gallery. Various nicknames accrued to Mr Hamanaka during his 26-year career at Sumitomo, only some of them printable: "Mr Copper" , "Hammer" (from his name, and the power he was said to command over prices), and "Mr Five Percent" (from the share of the copper market which he was believed to control). Mr Hamanaka is said to have particularly prized this last tag, which was originally applied to a very different businessman - the great Armenian oil magnate Calouste Gulbenkian. This perhaps provides the key to his character and to the whole affair, which looks more and more like a morality tale of corporate arrogance.

Mr Hamanaka's public utterances reinforce this sense of impregnable hubris. "There are various rumours and slanders against me," he told an interviewer in 1991, "although I am getting used to them."

Sumitomo was founded in the early 17th century as a supplier of copper to Japan's shoguns. But in the post-war period it had fallen behind its competitiors in the market for non-ferrous metals. Unlike its rivals among the massive Japanese corporations, Mitsubishi and Mitsui, Sumitomo had no copper mines of its own and thus no access to the raw material. According to employees in rival trading companies, Yasuo Hamanaka trumped them by coming up with a brilliant short cut: Sumitomo could control the flow of metal through the market by investing in copper futures and options - contracts to buy or sell a quantity of a commodity at a specified date in the future.

By the early 1990s the strategy had paid off handsomely. Sumitomo became the biggest copper trader in the world. But when the 1980s boom came to an end, nowhere was it felt more acutely than in Japan. Soaring property prices had fuelled a lending boom; when the bubble economy burst, the banks weresaddled with numberless loans that could never be repaid: estimates range from 40 trillion yen (pounds 24.2bn) upwards.

The cost of the bubble has affected Japan's business culture, exposing crime and huge fraud. The problem was starkly put yesterday by Seiroku Kajiyama, the Chief Cabinet Secretary and official spokesman of the Japanese government. "The moral fibre of all Japanese has deteriorated and they have become desensitised about money," he said apocalyptically. "I cannot help but express deep concern that such tendencies have become widespread."

Rogue trader, page 18