As China's largest aluminum producer, aptly named Aluminum Corporation of China ( ACH), better known as Chalco, has a direct line to one of the largest industrial metal consumers in the world. Because the firm is a completely vertically integrated producer, it boasts lower costs than many of its peers -- particularly at home, where an inadequate electrical grid has made input costs a major problem for margins. To be sure, Chalco's margins are well shy of those at established Western peers, but Chinese demand for aluminum and rising base metal prices could soon change that. Analysts expect this quarter to be particularly challenging for aluminum producers. Even so, those negative expectations are already priced into shares -- doing "less bad" could help to spur covering among shorts. A short interest ratio of 15.2 suggests that it would take more than three weeks of buying at current levels for short sellers to cover their positions in ACH. To see this week's short squeezes in action, check out the Large Cap Short Squeezes portfolio on Stockpickr. -- Written by Jonas Elmerraji in Baltimore.