MACD, also known as exponential smoothing average, is developed from double exponential moving average. The meaning of MACD is basically the same as that of double exponential moving average, 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.