Bitcoin is good investment but I wouldn't suggest to put all your money into it. I wouldn't suggest puting all your money into anything, not just Bitcoins. Every investment is a risk and there is always the danger of losing money so you have to invest with care and you always have to have some back up. Don't ever invest more then you can afford to lose.
It's not questionable that bitcoin is one of the good investment nowadays but i won't suggest anyone to invest ALL of your funds or money onto it. Ofcourse all business activities involves risks and loosing stuff and no one would like and dare to loose any amount or much more than what they had invested so it's much better to invest what you can afford to loose. And as much as possible one must be knowledgeable of what he is doing.
Absolutely every investment involves risks. There is no business which is totally risk free and same is the case with bitcoins. What makes business suitable for investment is lower risk rate. Bitcoins are actually offering that. They are rather letting people win more than losing in this crypto trading. Indeed it is sagacious to invest in multiple businesses according to their risk rate and keeping some cash with you is sagacious.