Career
He was known as "Mr. Copper" because of his aggressive trading style, and as "Mr. Five Percent" because that is how much of the world"s yearly supply he controlled. On June 13, 1996, Sumitomo Corporation reported a loss of United States$1.8 billion in unauthorized copper trading by Hamanaka on the London Metal Exchange.
In September 1996, Sumitomo disclosed that the company"s financial losses were much higher at $2.6 billion (285 billion yen).
Hamanaka was sentenced to eight years in prison in 1998 and was released in July 2005, one year early.
