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.
No modifications are required as Bitcoin can be split in 10,0000000 small units called Satoshi.If btc demand keep rising and supply is less for holding or other reason,bitcoin price will go so high that even 1 Satoshi would be worth something and people will start selling Satoshi for buying products or services even if they dont sell the whole coin