Copper has been in a long-term downtrend since 2011. A short-term rally may provide a shorting/sell opportunity within that longer-term downtrend.
Since August, the price of March copper (HG) has been moving within a downward sloping trend channel, the latest leg of the long-term downtrend.
While all channels eventually break, as long as it's intact it provides potential trading opportunities. A pullback to the top of the channel near $3 is likely to encounter resistance. Not only is this the top of the channel, but is also the breakout point of a November consolidation; a former support area, now likely to act as resistance.
Figure 1. March Copper (HG) Futures - Daily Chart
A rally above 3.072 warns the price may be transitioning to the upside, therefore place a stop loss in this vicinity.
If the trend channel holds, the trajectory provides a price target for the trade near 2.8 or slightly lower. The setup provides a reward/risk ratio of greater than 2.5:1.
Copper tends to rally in December and early in the year. This will quite likely push the price to the top of the channel and the potential entry point, but continued strength could push the price right through.