Well basically the value of cryptocurrencies all came from its demand and supply, anyone who had learned economics in their school will know how that works. Even without any financial background backing it the value of Bitcoin will always come from its demand and supply. Just take a look on how Gold has its value based on its demand and supply. It doesn't matter if Bitcoin (or any other cryptocurrency in that matter) exist virtually as even though it is, its supply is limited and also is obtainable to anyone who has a wallet in their hands.


P.S.
I don't know why you have posted this in the legal section, you should move this topic to another sections probably in the Economics.