Although it is not a bad decision to give up on such irrelevant stuff but you could actually do that through limit orders. If you have a range in mind within which you want to buy and the lower end and liquidat at the upper limit, all that can be set automatically in the exchange or you can use a bit to do that. However, I prefer long term holding because if you are buying and selling intermittently, you might end up gaining less than someone who simply concentrate on buying and storing safely and the later will enjoy the peace that comes with such method.