MACD (Moving Average Convergence / Divergence)
After delving into the world of moving averages there is no better place to go next than into the world of MACD. Why? Simple, the MACD is comprised of two moving averages. Some traders argue that there is no better technical indicator than that of the MACD, more often than not, this author tends to agree. The theory behind MACD is really the same theory behind trading any other form of a moving average cross. Generally a technical analyst can learn more from the interaction of two moving averages than he or she can learn from a single moving average in and of itself.
The MACD uses two exponential moving averages, more specifically a 12 day EMA and a 26 day EMA. The 12 day EMA is of course going to react to the market more quickly than will the 26 day EMA. When prices in the market begin to rise or trend upwards the 12 EMA will of course increase faster than will the 26 day. Visually this results in a MACD that is slanted upwards. Conversely when prices fall or trend downwards the opposite will occur and the 12 day EMA will decrease faster than will the 26 day, creating an obvious visual slant downwards. The MACD does oscillate at what would be considered a zero line. In other words, the MACD is either above or below the level that can be considered the third part of the equation. Some analysts refer to this line as the signal line, or the trigger line. Essentially this line is usually a 9 day exponential moving average of the actual MACD itself.
Whether you are a mathematician or not is hardly the point. One need not really understand the complexities of the calculations within a MACD, but rather it is only crucial to understand the basics of the math and what the MACD is trying to tell us as technical traders. For that reason, we will not further dissect the math. Instead, let us get to the point; how does a MACD forecast successful trades?
As is the case with trading moving average crosses, buy and sell signals derived from a MACD will come from the crossing of two lines. However, these two lines are not your two EMA lines, rather one is the combined level of the two EMA lines and the second is the signal, or trigger line (the 9 day exponential moving average of the actual MACD itself). The MACD crossing the signal line from above would indicate a buy order and conversely the MACD crossing the signal line from above would indicate a sell order.