I am not sure if you want to invest in bitcoin due to the rapidly changing prices
Every investment can be volatile, bitcoin is actually less volatile on the down side now than it was when it dropped from 30 to 2 dollars back in the day. It does depend on your time horizon, for instance if you hold property, that market can trend in one direction for decades if you bought tokyo property at its peak you were not going to get your money back. Basically if your investment horizon is more than a couple of years with bitcoin you should be good as long as new people keep adopting it.