75.9% ( 15,947,975 bitcoin) of the bitcoin is already mined so to circulate bitcoin all over the world there is only few bitcoin because many bitcoin user are holding bitcoin and waiting for price hike. So what would happen if the continue holding and we are left with only few bitcoin to circulate. So can it act as global currency or we need some modification.
It's the same problem with every other currency - USD, GBP or whatnot. There will always be speculators. There will always be traders. There will always be people who actually use bitcoin as a currency.
Just let it be...