Boll index is to calculate the "standard deviation" of the price and then find the "trust interval" of the price. The indicator has drawn three lines on the map, in which the upper and lower lines can be regarded as the pressure line and the support line of the price respectively, and there is also an average line of the stock price between the two lines, and the parameter of the Bollinger Band indicator is preferably set to 20. Generally speaking, the price will run in the channel formed by the pressure line and the support line.

MACD, called exponential smma, is developed from the double exponential moving average. By subtracting the slow exponential moving average from the fast exponential moving average (EMA), the meaning of MACD is basically the same as that of the double moving average, but it is easier to read. When MACD turns from negative to positive, it is a buy signal. When MACD turns from positive to negative, it is a signal to sell. When the MACD changes at a large angle, it means that the gap between the fast moving average and the slow moving average expands very quickly, which represents the change of the market trend.

KDJ, also known as stochastics, was first put forward by Dr. George Lane. This is a very novel and practical technical analysis index. It was first used in the analysis of futures market, and then widely used in the short-term trend analysis of stock market. It is the most commonly used technical analysis tool in futures and stock markets.