Jesse Lewisohn (1872 - November 30, 1918), was a businessman involved in copper trading with Lewisohn Brothers, and an owner of racehorses.
There is also archaeological evidence of ancient copper trading, prehistoric quartz mining, and stone tool making in the area.
Mr. Hamanaka was nicknamed "Mr. 5 Percent" - said to control that much of the world's copper trading.
After unauthorized copper trading by a former nonferrous metals department manager, we decided to introduce this new job rotation rule," a Sumitomo spokesman said.
One executive at Sumitomo said both the speculative copper trading and the involvement in the mob-connected pachinko industry reflected an undesirable move away from core businesses.
Analysts said Sumitomo would be hurt but not crippled by the loss from the copper trading.
In disclosing the losses last month, the company said they resulted from unauthorized copper trading by Mr. Hamanaka over a decade.
He also said that Mr. Hamanaka had said in the past that he did not violate rules covering copper trading.
Copper prices plunged in June, after the Sumitomo Corporation of Japan disclosed losses of $1.8 billion in copper trading.
The Sumitomo Corporation is using that strategy, for instance, to help offset its big losses from unauthorized copper trading.