From 50/50 (it could swing either way and you can have zero knowledge on which way it'll swing), to %1-100 being able to know before hand, how much can you know?
It depends on the market news because when Tesla purchased a big chunk of Bitcoins, for example, it was obvious the price of Bitcoins will rise and it did by some decent value.
But, when fake news is out and there are rumors about something then it is hard to distinguish and movement can be different from what we expected. At the same time, if you are skilled then you can easily identify market direction accurately. Hence, predicting market trend is completely different from gambling. So, do not get confused yoruself.