If your asking about "stable investment" then you are at the wrong place Because a Volatile market assures you nothing.
But if you can risk and know the consequences ?then i may say that In the Long run,I mean in future when you Hold then the profit will be indeed.
Like those early adopter of Bitcoin that taste their fruit after 8-9 years.
Right now, the only stable investment is gold. All the other investment assets, such as stocks, real estate, mutual funds.etc are behaving in a highly volatile manner. And if you check the Bitcoin charts for the last 6-7 months, you can see that the prices have fluctuated less than many of the established large-cap stocks. Bitcoin continues to be volatile, but this volatility is declining.