Currently, what major asset class is not in a bubble?  Bonds, stocks, real estate, how about the US Dollar money supply? US Debt is at 20 trillion

http://www.usdebtclock.org/

Blockchain technology is relatively new and is in the first innings for a baseball analogy. When it does go parabolic in the coming years, there will most likely be a blow off top just like the .com bubble in which many companies went bankrupt. In the crypto space, the blockchains will no longer be active on the net.