A 20X increase happened multiple times before 2017, I don't see why it couldn't happen again when you consider that the vast majority of people barely just know that bitcoin is electronic money. The recent crash was a great opportunity for the people who missed the boat, but I doubt that many newcomers would've had the courage to invest when everything was falling hard. It certainly was an easy way to double any amount of money. I think that cryptocurrencies will grow by an order of magnitude by 2020. It's still super early. The days of having $100 turn into $10M are likely gone forever though.