Looking at the 4-hour chart, you can see that after a strong downtrend, copper has been consolidating in a short-term uptrend. A break of the channel would complete the bear flag pattern and suggests not only a re-test of the August lows, but a resumption of the downtrend.
In my opinion, this is one to put on the radar. A close below 23,086 would be the potential trigger. I'm guessing tomorrow's (no set time currently) China August trade balance could be the catalyst here, with the market expecting a 6.7% decline in exports and 8% in imports.