With cryptocurrencies you also have other exchange risks, notably the risk an exchange is hacked or otherwise goes out of business. Imagine if you had been buy

With cryptocurrencies you also have other exchange risks, notably the risk an exchange is hacked or otherwise goes out of business. Imagine if you had been buying BTC on Coinbase and selling BTC on MtGox in 2013, making a great profit (on paper) through arbitrage, until MtGox tanked and all those profits were frozen.