who know bitcoin will become in 2018 i think its not possible it become 50k USD
Some speculators say bitcoin will reach 50K but not next year, more like 10 years from now i think it could reach 4-5K next year.
But to be honest we don't even know what will happen to bitcoin in 2 days from now

I'm not sure about whether Bitcoins can reach 50K range even in 10 years time but very confident that it can reach around 5K in next one to two years time. It should focus now to resolve all those issues currently Bitcoin is facing. If that happens then it will attract many new investors and it pushes its prices to very high.
50k is not a high price if Bitcoin can improve transaction speeds and lower transaction fees. As long as it outperforms regular methods of payment on these two benchmarks, people will keep flocking to it. Compared to the amount of money that is being moved around internationally, the amount of money in Bitcoin is still no more than a wet fart. 50k in 10 years or by 2030 is not even close to an optimistic estimate as long as Bitcoin remains on top from a technological point of view.