As a back-of-the-envelope calculation, cryptocurrencies are [over]valued with a market cap of ~$70bn (from https://coinmarketcap.com/) of which BTC itself constitutes just under half.
World broad money supply is estimated around $80 trillion (not including many other stores of wealth and financial instruments which are not money). So the first conclusion one could draw is that cryptocurrency is also a surprisingly high proportion of currencies in circulation, at around 0.1% (treating cryptocurrencies as equivalent to broad money and exchange values as accurate)
A second would be that cryptocurrencies which apparently use 1% of their capital value in energy per annum to function even at low transaction volumes are unlikely to be a viable long term solution to the problem of exchange.
My off-the-cuff response is that cryptocoins behave more like a commodity more than a currency, so their value is always relative to cash, not part of global cash reserves.
World broad money supply is estimated around $80 trillion (not including many other stores of wealth and financial instruments which are not money). So the first conclusion one could draw is that cryptocurrency is also a surprisingly high proportion of currencies in circulation, at around 0.1% (treating cryptocurrencies as equivalent to broad money and exchange values as accurate)
A second would be that cryptocurrencies which apparently use 1% of their capital value in energy per annum to function even at low transaction volumes are unlikely to be a viable long term solution to the problem of exchange.