I think Bitcoins saving is quite risky, because compared to other forms of investment such as gold or dollars, cryptocurrency is more risky because the possibility being hacked is so high, we could be stolen bitcoin or the ability the network system attacked, you lost all bitcoin in the second. In addition,fluctuations in bitcoin price are highly impacted by the market so investment in bitcoin is unsafe solution. 
I will say, bitcoin investing is very high risks, so since the day we accept to use cryptocurrency investment we have to accept that, Secondly, bitcoin can not be hacked because the system of blockchain is extremely high security so there are no hack about bitcoin recently, but hackers can hack the exchanges where we transfer to, because the exchanges don't use the security methods like bitcoin.