Jest, perhaps. But you can already buy copper bullion for "investment" purposes the same as you can do with gold and silver:

https://www.jmbullion.com/copper/copper-bars/

This is, of course, for the express purposes of parting fools who listen to too much AM talk radio from their money. Copper is worth, what, a little under $6 a pound right now? So these one ounce ingots that they're hawking for nine bucks each in reality contain about 37 cents worth of metal.

Copper is self-evidently not an investment or speculation vehicle, unless you are able to front the money to deal with it in quantities measured in tons.