The economic reach of Bitcoin is an interesting subject of discussion. In the end there will be a maximum of 21.000.000 BTC. BTC is a eight-digit number.
I suppose that a currency can only be leading if it has the possibility ta pay in small amounts, equivalent tot e.g. dollarcent or eurocent. This statement limits the range of BTC, will the satoshi be the future euro/dollarcent?
In that case the maximum money supply wil be BTC 21.000.000,00000000 is e.g. EUR 99.999.999.999.999,99 (by the way: interesting exchange rate).
The money supply in the Eurozone (M3) is over EUR 10.000.000.000.000
So without any constraints, the structure of the BTC satisfies the necessary condition.
Let's inventory the other constraints.
Indeed the Bitocoin is still the best and stable among other cryptocurrencies and as the mother of all Altcoins.
As you can see the trend from last 2017, it shows how Bitcoin rise up until the end of 2017.
Though, there are some dips during January, 2018 but that is normal in trading and as speculated, the price will rise up again by February, 2018 so we better to invest now and hold it until we reached the desired income in the future.
Don't be discourage is the price is going down but instead take it as opportunity to invest additional Bitcoin.