[nfin]

You should look at it in a logarithmic scale (like all things that has been growing exponentially):

https://bitinfocharts.com/comparison/bitcoin-price.html#log

Here you can see how long it takes to double or get 10x bigger. And you see that at times bitcoin did grew faster (the curve was steeper at some moments). You also see that the corrections were bigger... so volatility does seem to decrease (until now).

So it is not new that is grows fast. Why it does grow fast? I prefer to let this question open. There are many different possible answers. Maybe the actual system has no solid fundamentals? (if every runs to the bank, the is not enough there for everybody o_o). Or the younger libertarian generation prefer it to gold? Or it could bank the unbanked of this world (once lightning implementations in bitcoin and other improvements are past alpha/beta stadium)? Or because venezuela might not be the last state with hyperinflation and cryptocurrencies might be the alternative (once scaling through lightning/... is improved)? Or a new way for machines to exchange with each other?

Obviously speculation on some of these (and other) reasons is still dominating... but it may mean that people seem to belive these secenarios might happen