On one "derivative", I remember reading a while back that the amount of paper "gold" of various kinds in circulation was at least twenty times the amount of actual refined gold on the planet.

Paper gold kinda highlights the whole game: in essence they are just gambling chits whose erstwhile value is related to the market price of gold bullion, but they can in effect only be sold or exchanged for more paper of some kind or other.

Interestingly the existence of so much "paper gold" massively suppresses the demand and thus the very value of the gold bullion itself.