Zinc prices rose to four-month highs on Monday as worries about tightness on the London Metal Exchange surfaced after data showed more than half of stocks in its approved warehouses had been marked to leave the system. Benchmark zinc on the LME was up 1.2% at $2,851 a metric ton at 1030 GMT, having earlier touched $2,876 a ton, the highest since March 28. Overall stocks of zinc in LME warehouses stand at 118,225 tons. Cancelled warrants or metal earmarked for delivery at 50% suggest another 59,900 tons waiting to be loaded out. But traders say there are doubts about whether much of that zinc will leave LME warehouses ... (full story)