Dear, you can learn from this method: analysis of the operation strategy of the Hang Seng Index Bollinger Band: 1. The bollinger band is a magical indicator. In this system, any rise must be supported by the lower rail and the middle rail, and any fall must be pressured by the upper rail and the middle rail, and every time is no exception! Therefore, all quotations generated when away from these three lines are "false" quotations. 2. In HSI operation, if the market falls below the middle rail and stays away from the lower rail, at this time, because the market is not supported by the lower rail, it is strongly suppressed by the middle rail, so even if it suddenly breaks through the middle rail, it will take one minute to complete the liquidation of empty orders. Don't be scared to close the empty orders immediately! 3. If the market breaks through the middle rail and stays away from the upper rail and is supported by the middle rail, even if it suddenly falls below the middle rail, it is necessary to wait until the end of this minute to close the position. Don't panic, stop loss and order more immediately!