Investing in short-term means one clear point: do not chase highs, enter at suitable positions, which is inherently speculation. For long-term investing, the key is not to miss out; actively buying when you are already at a loss means you have confidence in it. First, buy a starter position when you are optimistic, and then add to your position when it drops. In the long run, you should at least hold on until you get a significant result before exiting. Being at a loss shows your courage in believing in its potential. The worst-case scenario is when you are particularly optimistic and insist on buying at the lowest point, which may lead you to miss out altogether.