The current thing driving it might be a combination of factors, among which is the North Korea situation with chinese investors moving funds into cryptcurrencies?
1. Chinese investors see crypto as a way of moving currency outside of China. The Chinese government has recently cracked down on movement of money outside of the country.
2. The rise of populism could drive people into crypto. The rise of actors like Donald Trump, Marine Le Pen, Geert Wilders (although defeated) implies major currency instability, especially around USD, EUR.
On (2), from what I understand Gold has become less of a good hedge against world economic stability as well.