I also believe that bitcoin can reach $60000 mark. Because we all aware of the fact that in the last quarter of 2017 the big players were entered in to the market and then we all know what happened. I think the same kind of things can happen this year also, when small investors will out from market by selling their bitcoins & altcoins at very low price & then big players will buy enter and then small players will not even get a chance to enter in the market. That's why i think instead of selling our coins we should hold.