>The ratio of iron-ore derivatives to physical trading volume was about 25 times, far lower than the 80-100 time for more mature commodities such as gold and copper, according to a study by Hong Kong Exchanges & Clearing.
https://www.bloomberg.com/professional/blog/expect-chinas-fu...
Silver is quite a lot worse btw
Might be worth pointing out that this isnt surprising given the activity of speculators in the market. Without markets would get cornered for investment and industry would cease.
edit1: There is however also an incentive to keep individuals from investing into precious metals due to monetary considerations. Derivate induced volatility is one way to do that. https://wikileaks.org/plusd/cables/1974LONDON16154_b.html
edit2: Also worth considering is that the large central bank holdings can and will be loaned out to maintain price stability if push comes to shove and gold were to rise drastically.