Copper prices have bounced from their lowest point since the summer of 2009, suggesting the gloom pervading dealing rooms in the world's three major trading centres might be about to give way to a brighter outlook. Sentiment has been nothing but negative for three months, according to the proprietary Marex Spectron global copper sentiment index, which tracks dealing room dynamics in Shanghai, New York and London. The index fell 1.7 points last week to minus 95.4 just as prices started to turn. It has only been lower during the 2008 global financial crisis. "Given this, we believe that we are very close to the lows for copper, if we have not seen them already," said Guy Wolf, the head of market analytics at Marex.