Late-night Mark: What is the simplest order logic? The simplest is that if you are bullish at this moment, then you should go long. If you are bearish at this moment, then you should go short. The falsification of the logic is determined by your order decision; if you go long and then it drops, it proves that your initial idea was wrong. However, the ultra-short-term rise and fall of the market are determined by short-term buying and selling forces, which are unpredictable. That's why stop-loss lines are used; after hitting the stop-loss, it is the last safeguard to falsify your idea. Once you exit, you exit. Even if the price rises back, it’s not yours anymore. At worst, you can chase after the rise when it comes back.