At the core of economic and industrial growth is always demand or lack thereof for base metals. After all they are at the well-springs of overall growth. Copper for example has been nicknamed Mr. or Dr. Copper given a PhD in economic forecasting abilities regarding future economic conditions. For copper and other base metals, the higher the demand the rosier will be the future.
As with others, since commodities are still priced in dollars the level of it can determine prices as well. A lower dealer will generally mean higher prices and vice versa. Given easy monetary policies globally beginning in 2008 and expanding globally since, the value of the dollar has declined.