Guess the future trends. If the pie falls to a relatively low position. After stabilizing. Re-enter the uptrend. Does that mean that the rise of the pie will be like the previous process? Vampire cottage. After completing a stage, lead the copycat to become stronger. So it’s time to invest in a big pie or a copycat. Wait until a copycat is generally low. Entering. Of course, if you invest in the short term, it is still possible to have a correction. The situation is not suitable at this stage. As for the contract, it doesn't matter. You can make money from both long and short positions