Originally Posted by Fermion
Seems a reasonable thing to do. It is a fixed resource with relatively high extraction costs and will be in high demand as the world transitions from a coal/oil powered grid to a wind/hydro/solar/geo/fusion powered grid and all of the millions of miles of wiring needed (plus the 100 or so pounds of copper used in electric vehicles for motor windings and battery interconnects).
I would be a lot more comfortable right now with a warehouse full of copper than an equivalent monetary amount of rubles in my bank account.
I worked for Anaconda Copper in the 1970's and early 80's and watched the trend towards substitution of copper and copper alloys destroy that company and its competitors. I was smart (lucky?) enough to leave and get into a big oil company at the right time (1982). Copper is a raw material that is constantly under pressure for substitution:
The housing industry uses much less copper than it used to with the advent of PVC drain pipe and now that's going to the pressure side of the plumbing.
We saw the U.S. Mint contracts fade away when they eliminated copper pennies and copper in clad alloys.
The next big elimination was with Harrison Radiator and other radiator producers when the radiators went aluminum for tubing and fin stock.
The rest of the vehicle industry now uses less copper and smaller diameter in wiring with low current lighting and other applications.
The only thing that makes copper and copper bearing alloys successful for short periods of time are when the U.S. gets in a war (cartridge brass, other armament) or when the undeveloped countries start building and the economies improve substantially.
All the major water tube, sheet, and wire mills in the U.S. are now closed permanently due to poor economics for copper products and foreign competition. I worked in several of them and they are boarded up for good. Copper mining in the U.S. is practically non-existant. Most copper is mined and processed outside of the U.S. and those mines are mostly nationalized (Chile for example).
Think about the above before making any investments in copper.
When I worked in that industry, the saying was.."the only way to make any money in the non-ferrous metals industry is be a scrap dealer".