Precious metals

Gold

Gold is a very special asset. Until about 1971, currencies were linked to gold (Bretton-Woods), causing gold to have a fixed nominal price. Since then, gold has been very volatile. It is hard to tell if gold has any return. Fundamentally, there is no reason to assume gold has any return other than keeping up with inflation. Is gold then a good inflation hedge? No, gold also doesn’t really have a clear relationship with inflation. The only thing that the gold price might be related to is uncertainty. As gold is very unrelated to other assets, it is a worthy diversifier and asset of last resort. Gold is also very easy to store.

Silver

Silver is a brother of gold. Short term, it tends to move similarly. Long term, it may diverge significantly.

Platinum, palladium, others

These are more obscure and semi-industrial.