Around the 1990s, Yasuo Hamanaka of Sumitomo Corporation came to control 5% of the world's copper. He used various unscrupulous means, such as fake trades, forged documents, and hoarding, to manipulate global copper prices. Then, a twist came with the resurgence of copper mining in China. Sumitomo lost USD 2.6 billion when the scam was uncovered in 1996.