what happened to cryptocurrency? nothing, just an ordinary routine. price fluctuations are common in cryptocurrency except that maybe the current decline is too much 
I hope that the current decline will be the last decline in the price of Bitcoin and the coming time will give a great fortune to the value of Bitcoin and again we will see a golden era in the Bitcoin and all other altcoins. I am sure that from the coming year we will see a great year like the year of 2017.