Inventory of copper in China has surged due to speculative imports, disguising the level of true demand and making the metal less reliable as an economic indicator. Chinese traders are taking advantage of an arbitrage opportunity to buy copper stockpiled at London Metal Exchange (LME) warehouses in London, and move it to Shanghai, where it can be sold at a higher price on the Shanghai Futures Exchange. In Shanghai copper ended at 37,620 yuan ($5,774) per ton last week, 5% below a recent high in early March. According to data released after trading, on-warrant copper inventories was at 177,000 tons marking an 11th straight weekly increase. This is double the inventories during March 2015. Investors predicting that the yuan will lose value are buying Shanghai copper in anticipation that yuan-denominated prices will rise. That demand has at times boosted the metal’s Shanghai price above that on the LME. In late January, copper traded at around US$4,750 a tonne in Shanghai, compared to $4,440 per tonne in London.