Red means that the price is falling, that is, the market is bearish. When the closing price of a futures contract is lower than the closing price of the previous day, the histogram on the K-line chart is usually expressed in red, which is called "negative line". The red bar chart shows that the selling power is strong, the market supply exceeds demand, and the price falls.

Green means that the price is rising, that is, the market is bullish and the mood is high. When the closing price of a futures contract is higher than the closing price of the previous day, the histogram on the K-line chart is usually expressed in green, which is called the "positive line". The green bar chart shows that the purchasing power is large, the market demand is greater than the supply, and the price is rising.