These commodities have two things in common, which are great for traders, they are price inelastic – per your economics 101 – demand will not change in line with supply shortages leading to price spike potential.
The second is that they are in the lower end of their 30-40 year trading ranges. So, looks like plenty of upside for the medium term speculator. In fact, opening a “core” position could be fruitful in these. Besides my trading I have a longer term holding in the softs ETF traded in London and it would be worth having an exposure in SLV, though in fact a small longer term position as a silver spread trade could work out from these prices, $17 silver ain’t going to last long.

