The question of whether one ought to invest in crypto-currency or not depends on your fate, whether you think crypto-currency will become a continuing trusted store of worth.
Despite the volatility in trading this currency, the fears may linger though not necessarily anything to worry about.
So if you think Bitcoin has a 10% chance of becoming a long-term trusted store of value, it is a good investment with a nice expected return. It is still very risky but professional investors should invest some small portion of their portfolio in this case.
If you think Bitcoin has a 1% chance of becoming a long-term trusted store of value, you should not invest.
If you think Bitcoin has a 0.001% chance of becoming a long-term trusted store of value, you might consider a short.