Copper surged by the most in more than 16 years, after a wave of buying from Chinese investors triggered one of the most dramatic moves in the market’s history. Prices gained as much as 11% to trade above $14,500 a ton for the first time ever, before a sharp retracement on Thursday afternoon. The industrial metal, which is used in almost every electrical application, has risen about 21% since the start of December, firing up copper bulls who have long been predicting a surge in prices. “You wait a lifetime for markets like this,” said Mark Thompson, a mining executive and former trader at Trafigura Group with three ... (full story)