Anytime you invest in commodities such as metals there is high risk. It is as likely to go down in price as up and only the professionals who deal in those items on a daily basis are going to come out ahead.
The reason is that they know the inside story before those who are not professionals and they act on it long before you would ever figure out what is going on.
If you buy copper with the intention of using it, that's one thing.
But if you buy it only because you hope it goes up in price later, you're wasting your time. It just sits there, not doing anything.
A better option to invest your money would be dividend-earning stock. At least those spit out a check every three months while you're waiting to sell it.
It's hard to say.
Last year I saw copper was at $8 a pound. I checked today and its nearly $3 a pound. Is it worth the time and storage to make copper a primary investment?