KDJ index, also known as stochastics, 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.

K-line is a quick confirmation line-the value above 90 is overbought, and the value below 10 is oversold;

Line D is a slow trunk line-the value above 80 is overbought and the value below 20 is oversold;

J-line is a direction sensitive line. When the j value is greater than 90, especially for more than 5 consecutive days, the stock price will at least form a short-term head, while when the j value is less than 10, especially for more than several consecutive days, the stock price will at least form a short-term bottom.