Buy low and sell high is easy to say than to do. But most ppl are losing money. So do not be obsessed with it. Due to the potential, we could buy it for the long term. We know bitcoin's price is hovering around $200-300 for long time. If we buy at that time, we could sell at $450 recently and get $150 for one btc. Do you know what I mean? Just buy and hold.