On July 2017, price of bitcoin was around $3000, in December 2017, Bitcoin got the new ATH of $20000, therefore, I think it's possible to reach $30k by the end of this year.
I am not sure about reach 30k$ bitcoin price end of this year but definitely i can said that bitcoin price will jump 15k$ in this year.
Currently the market situation very bad think so totally i can't trust altcoins marketcap but I can give you some opinion you can still decide top altcoins then it will be better.