Nobody knows when it will happen. It can be very long correction actually, even longer than in 2013 but if it recovers already in this year, then I think 50k+ it's possible in 2018 as well as 2k+ for Ethereum and a lot of Xs for many alts. But don't rush with these things, invest only what you can afford to lose. A lot of projects especially ICOs will scam and disappear from the market.