I agree with your idea, if there is a substantial money available, you have the option by splitting it up, if your investment losses, you have still some money in the bank. Investing is always accompanied by risk and the possibility of losing is high especially when you are still a beginner. Bank is a safe haven for those who want to save their money for long term.
I know that bitcoin can also be used at that time but last week there were some denial of service attack on the website and it was crashed because of the panic in market, so it is always recommended to have some money in your account as well to coup up with the emergency.