One of the most popular MACD signals has been signal line crossover. The MACD line' 9- day EMA is the signal line. It trails the MACD as a moving average of the indicator, making it easier to spot MACD turns. When the MACD rises and crosses above the signal line, it is said to be a bullish crossover. Whenever the MACD falls and crosses just below the signal line, this is referred to as a bearish crossover. Depending on the quality of the move, the crossover could last few more days maybe a few weeks.