How to see the stock market boll indicator

Taking Tom Tom as an example, open the software, enter boll, and bring up the boll indicator:

The boll indicator is generally also known as the Bollinger Bands indicator, full name "Bollinger Bands", which is based on the calculation of the "standard deviation" of the price of a stock, and then the trust interval of the stock price. "The Bollinger Bands indicator is based on calculating the standard deviation of a stock's price and then finding the trust interval of the stock price. In practice, the investor observes the relationship between the upper, middle and lower tracks and the stock price k-chart to determine the subsequent trend of the stock price and to prepare for the next stage of the investment strategy.

But the software comes with the boll is more difficult to understand the logic behind it, you can go to find some teachers adapted boll indicator formula, will contain logic, ideas, to wealth pool as an example: