"world currency" is an insanely high bar. why not address the question of whether cryptocurrencies will find a niche and how big that niche could be? obviously bitcoin is not going to be made the sole "world currency." it's a dumb question to begin with. people are buying bitcoin with the idea that it is playing some role in the global economy and will play a larger role in the coming years. larger than 6 or 10 billion dollars worth. there's a lot of space in between 10 billion and the world's total money supply.  if there's a 100-bagger, i won't give a flying fuck about the fact that bitcoin didn't become the world currency.