The candle diagram is the K line. Color represents the direction of fluctuation, generally red rises and green falls in China, or hollow rises and real falls; Entity refers to the column outside the shadow line. The upper and lower sides of the column are the opening price and closing price of the current period. Specifically, the red column closed up and fell, and the green column closed up and fell. It is said that it originated in Japan in the18th century. At that time, Japanese rice commercial maps were used to represent the price changes of rice, and then they were widely used in the stock market and futures market because of their unique plotting methods. K-line chart is drawn according to the opening price, the highest price, the lowest price and the closing price of each trading day or each analysis period. The structure of the chart can be divided into three parts: upper shadow line, lower shadow line and intermediate entity.

K-line, columnar, consists of shadow lines and entities. The rectangle in the middle is called solid, the thin line above the solid is called shadow, and the bottom is called shadow. The entity has a positive line and a negative line. K-line is a special market language, which is divided into daily K-line, weekly K-line and monthly K-line. There are minute line and hour line in dynamic stock analysis software. Different forms of K-line have different meanings. K-line diagram contains many characteristics such as intuition, strong three-dimensional sense and large amount of information, and is rich in traditional oriental philosophy.