If you have sell when the price has not risen high enough and just to make a small profit, then you can buying it again but look first trend at that time, if the trend will still move up and the market will likely continue to increase then buy is the best. But if you see the trend will fall back, it will be better to wait again.
We should also be careful in your sales zone. Although markets are sometimes overcrowded, you have to learn how to sell orders because if you are busy, do not expect to be rich. You also need a good idea from the community to talk about bad things being sold.