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.
Every investment is risky because of the good return that it offers. My opinion about this is that bank offers products and services in a more conservative manner than cryptocurrencies does. For instance, the aggressive market fluctuations of bitcoin makes its investment more risky. For me both are different but although Im a huge fan and supporter of cryptocurrencies, but even that i have to say that banks are more safe at the moment, depends on which country you live. So cryptocurrencies are and will ever be a high risk invesment. So it will take a long time untill you can really say that cryptocurrencies are a save investment.