I think today, Bitcoin's biggest danger is not the central banks or government agencies but the technology behind the bitcoin. Anyone, any group can use its technology to create new coded currencies. The rapid development of other currencies has proven itself. From 2017 to 2018 we have witnessed many interesting things of Bitcoin and Altcoin are very volatile. Bitcoin price increase and discount Altcoins are born as much and Altcoin can compete and occupy the position of Bitcoin that is ETH. It is a potential Altcoin can compete with Bitcoin in the future.