The price of copper has fallen by nearly 50 percent to $2.36 a pound since peaking in early 2011, but Credit Suisse equity strategists believe the decline isn’t over. They point out that the metal’s price remains some 140 percent above its all-time low, and supply is still running high. And when a commodity is in excess supply, the strategists suggest, up to a third of production needs to fall below the cash cost before production cutbacks bring the market back in balance. For copper, that suggests a price level nearly 30 percent below today’s prices, or between $1.60 and $1.70 a pound. Another reason to be bearish: About 43 percent of copper demand comes from China, and 70 percent of Chinese copper imports are used as collateral to finance loans. Many of the loans, in turn, fund carry trades in which investors borrow U.S. dollars to buy higher-yielding Chinese yuan. But Chinese central bankers have been cutting interest rates and boosting lending in recent months in an effort to juice the economy. That has weakened the yuan, which has led investors to unwind their carry trades, sending copper flooding back onto the market and lowering prices. On Monday, the Shanghai Composite Index recorded its sharpest one-day drop since 2007 on news of poor industrial profits, making an end to currency-weakening government intervention unlikely. Copper’s slide isn’t over yet.