The key is that you should learn how to do statistics. For example, when doing trend statistics, you can set 100 the changes of low-priced stocks after falling. This is especially useful for the statistics at the end of the decline, and it is often effective to use the statistics at the end of the decline. On the contrary, the statistics of the end of the bull market can be carried out through the comprehensive data of 100 before rising and 100 before falling, with historical data. The key is how to use the data model for analysis.