Supply and demand for copper change constantly. New sources are discovered, mines collapse, workers go on strike, products that use it wane in and out of popularity, weather affects shipping conditions, and so on.

Suppose you learned that growing political instability in Chile (the largest producer of copper) will greatly reduce the productivity of its mines in two years. Holding all other factors constant, will cause the either demand or supply curve to decrease or increase? . As a result of this shift, price will go either down or up? . Therefore, ignoring storage costs, it either would or would not be rational for a person to buy copper now to store for later?