Prediction is important. It already becomes the bloodstream of this investment. Because of you don't predict and don't believe on it then there's nothing to trade. I invested in bitcoin because of the belief that at some time my investment will go high which is a form of prediction. I predicted that the price will go up and that is the time for me to sell my bitcoin. I also predicted that after selling and if the price goes down back again then I will buy more BTC because that it is the time for me to re-invest. So, see it? Prediction is always used.