The fact is that no one knows what will happen over the next few months or year or whatever. You might make a better guess if you know the answers to just two of the numerous questions (1) when will the Fed raise rates and by how much; and (2) will Greece leave the eurozone and if so, when. The "experts" are just guessing.

Like with any investment, stock market, currency, etc., it could go up or it could go down. Very seldom is it a straight or constant shot up OR down.