It's been called Doctor Copper because the metal is not just fundamental to the creation of electricity, and thus daily life, but because it's long been used as an indicator of global economic health.
And the weekly copper chart, shown here in cents per pound, suggests the world's economic health is not good.
The dominant feature on the chart is the equilateral triangle pattern. This pattern forms where there is a balance of buyers and sellers and no clear direction. It's a pattern of indecision but when the market finally makes a break, the pattern is used to establish the upside or downside targets.
The downtrend trend line in the pattern starts in September 2011. The uptrend line starts October 2011. The result of these two valid but opposite-direction trend lines is the equilateral triangle pattern.
The height of the pattern is measured from the base. This value is then projected downwards from the point at which the price moved below the uptrend line in March 2013. This gives a downside target of $2.50. It took a very long time for the copper price to reach this target and this reflects a slow but steady slowdown in global economic growth.