Bitcoin creates the risk of financial system stability in the event of a bubble burst, as there is an interaction between the virtual currency and the real economy.
"There is a risk of high price volatility because its value is determined on the expectation of future supply and demand.
If governments regulate bitcoin exchanges then volatility may reduce a lot because currently, some big whales may be doing pump and dumps.
That doesn't mean that its collapse would be as dramatic as you think.
IF Bitcoin is there, what will be the price after 20 years ?? It fell from $20,000 o $6,500 in 2 months

If you're new to bitcoin investments then it is new to you but for the old investors, it is common to them because this kind of high volatility is quite common in bitcoin investment. You can check the history of bitcoin price movements then you will come to know.
Anyway, bitcoins are only for high-risk takers not for conservative investors. If you think you can't take a risk then invest your money either in bank deposits or gold.