The most favourable investment is bitcoin, and I call it the most favourable is because it gives choice of what you want to invest, time, period, management and operations.
You know Bitcoin has a high fluctuation in value, for that reason no one can guarantee Bitcoin as a profitable investment. It is very difficult to predict the value of Bitcoin because its value follows demand and supply or its value is determined by market forces, due to this factor you can profit overnight and can lose in a matter of hours.
Investing in Bitcoin is the same as you risking money for something that can be worth 0, if it's analogous if no one else is doing Bitcoin transactions then your assets won't have a price at all. Crypto investment which is full of speculation there is no certainty there, sometimes it can be profitable and it can also be a loss.