https://en.wikipedia.org/wiki/Gold_reserve#Officially_report...
I think individuals with an actual portfolio of investments will hold gold or have some exposure to gold.
Also, you wouldn't expect gold to be widely held when you consider things like Executive Order 6102: https://en.wikipedia.org/wiki/Executive_Order_6102
Basically, the US government forced everyone to sell their gold in 1933. US citizens only regained the right to hold gold in 1974.
Governments are going to find it much harder to enforce such an order when it comes to cryptocurrencies.