K-line chart, a kind of technical analysis, was first created by the Japanese in19th century. At that time, Japanese rice traders used it to record the rice market and price fluctuations, including opening price, closing price, highest price and lowest price. Positive candles represent the market's rise that day, and negative candles represent the market's decline. This chart analysis method was particularly popular in China and even Southeast Asia at that time. Because the chart drawn in this way looks like candles, and these candles are black and white, it is also called yin-yang line chart. Through the K-line chart, people can completely record the market performance every day or at a certain time. After a period of trading, the stock price forms a special region or form on the chart, and different forms show different meanings. Some regular things can be found from these morphological changes. The forms of K-line chart can be divided into reverse form, arrangement form, gap and trend line. The post-K-line chart is introduced into the stock market and futures market because of its ingenious and unique drawing method. The drawing method of K-line chart in stock market and futures market includes four data: opening price, highest price, lowest price and closing price. All K-lines are centered around these four data, reflecting the general situation and price information. If you put the daily K-line chart on a piece of paper, you can get the daily K-line chart, and you can also draw the weekly K-line chart and the monthly K-line chart.