MACD, also known as exponential smoothing average, is developed from double exponential moving average. The fast exponential moving average (EMA 12) is subtracted from the slow exponential moving average (EMA26) to get the express dif, and then the MACD column is obtained by 2× (9-day weighted moving average DEA of Express DIF-DIF). The meaning of MACD is basically the same as that of double moving averages, that is, the dispersion and aggregation of fast and slow moving averages represent the current long and short state and possible development trend of stock prices, but it is easier to read. When MACD turns from negative to positive, it is a buy signal. When MACD turns from positive to negative, it is a signal to sell. When the MACD changes at a large angle, it means that the gap between the fast moving average and the slow moving average expands very quickly, which represents the change of the market trend.