My point wasn't necessarily to double your position in one go. The price fluctuates $50-$100 daily or has been. It wouldn't be too difficulty to do that a few times and make decent profit with the price being so volatile right now.
If you know what you're doing, and are willing to take the risk, then current price swings can be rewarding. However, if it was as easy as you are saying, everyone with at least some sort of market understanding would be doing it. Looking at the charts and the fluctuations of the last 24H for example is easy, but actually opening and closing positions at the right moment is completely different.