Hey there,
Yes, certainly a risky play and will move along with the price of copper. Small cap materials like this one move in one of two ways. They will outperform and do really well if the price of the metal they product (in this case copper) rises. If the price of the metal drops, then they will underperform in a big way.
In effect, they are high risk, high reward plays. ARG has additional risk now as its trading at all time highs - so it is particularly vulnerable to a dip in copper prices. It is definitely not one you can buy and forget for the long-term. It is one i'd be monitoring on a regular basis.
I think copper prices still have room to run upwards, but they are also trading at levels not seen in a decade. So once again, vulnerable to a pullback here.
Mat