I think bitcoin is more risky compared to banks. Bitcoins price is so volatile and that is what it makes it risky. On the other hand banks also have risk but it is lower compared to bitcoin. Banks may go bankrupt and you will lose money but that is only a little chance that it will happen compared to bitcoins volatility.
I think that also that bitcoin investment is more riskier than bank investment. In bitcoin you can't predict the price of bitcoin every now and then but in bank your investment will be the same on what your actual deposit and might have some interest in next few years.