I only do very short term trades unless we're in a confirmed bear market. My approach for buying back in when I successfully sold high, is to start off with an idea in mind of where I think the price will fall to. If it keeps moving in that direction without resistance, then I watch it go. If it gets hung up after falling a bit, even if it's nowhere near my target, I've had most success with just cutting it off there and buying back in early. In periods of low volume trading, the longer you wait for the price to move, and it doesn't, usually means the price is going to change direction for at least a little bit before trying again. Sometimes it falls more after bouncing, but even if it does, with this approach I'm usually able to increase my stack so it's a win no matter what.