K-line chart is a kind of chart source in Tokugawa shogunate era in Japan. It was used by businessmen in Japanese rice market at that time to record the market and price fluctuation of rice market, and then it was introduced into stock market and futures market because of its ingenious and unique drawing method.

At present, this chart analysis method is particularly popular in China and even the whole Southeast Asia. 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, we can completely record the daily or periodic market performance. After a period of trading, the stock price forms a special region or form on the chart, and different forms show different meanings. We can find some regular things from these morphological changes. The forms of K-line chart can be divided into reverse form, arrangement form, gap and trend line.