If you define success as a surging market price, crypto currencies have been incredibly successful, with Bitcoin and Ether leading the way. However, viewed as currencies, crypto currencies have not made much headway as mediums of exchange or stores of value. I argue that that the characteristics that have made crypto currencies so attractive to traders (the volatility and large price movements) have made them unattractive to transactors, and that the promoters of crypto currencies need to change both their marketing and design focus towards making them succeed as currencies.
Slides: http://www.stern.nyu.edu/~adamodar/pdfiles/blog/CryptoCurrencies.pdf
Blog Post: https://aswathdamodaran.blogspot.com/2017/08/the-crypto-currency-debate-future-of.html
