How to treat the boll line in stock?

The bollinger band index is divided into high line, middle line and low line. The high line of the bollinger band can be used as a reference for the pressure level, and the low line can be used as a reference for the support level interval. Under normal circumstances, when the third line of the Bollinger Band indicator is in a downward trend, the stock price runs between the middle line and the low line, indicating that the stock price is in a downward trend. When the third line of the Bollinger Band indicator is on the rise, the stock price runs between the middle line and the high line, indicating that the stock price is on the rise.