Forex Trading - Moving Average Convergence Divergence

Moving Average Convergence Divergence – MACD

MACD, which stands for Moving Average Convergence Divergence, is a trend-following momentum indicator that shows the relationship between two moving averages of prices. Developed by Gerald Appel, MACD is one of the simplest and most reliable indicators available. This tool is used to identify moving average which indicate a new trend, regardless of whether it is bullish or bearish. After all, the most important priority in trading is to find a trend, because the most money revolves around it.



With MACD chart, you'll usually see three numbers that are used to configure it:
1. First is the number of periods that is used to calculate the faster moving average
2. Second is the number of periods that is used to calculate the slower moving average
3. Third is the number of candles that are used to calculate the moving average of the difference between faster and slower moving average

The lines on MACD charts are often misunderstood, two lines that are drawn are not the moving average of prices. They are the moving average of the difference between the two moving average.

In our example, the faster moving average is the moving average of the difference between 12 and 26 periods of moving average. Slower moving average outlines a previous average of MACD lines. We calculate the average of the last 9 periods of faster MACD line, and outline it as a slower moving average. This moderates the original lines, giving us a more accurate chart.

Histogram outlines the difference between faster and slower moving average. If you look at the above chart you will see that when the two moving averages separate, histogram becomes greater. This is called divergence, because the faster moving average is diverging from the slower moving average.

When the moving average lines come closer together, histogram becomes smaller. This is called convergence, because faster moving average is converging, coming closer to slower moving average. This is why this indicator is called the Moving Average Convergence Divergence.

MACD Formula

The most popular formula for the "standard" MACD is the difference between 26-day and 12-day Exponential Moving Averages (EMAs). This is the formula that is used in many popular technical analysis programs and quoted in most technical analysis books. Using shorter moving averages will produce a quicker, more responsive indicator, while using longer moving averages will produce a slower indicator, less prone to whipsaws.

Of the two moving averages that make up MACD, the 12-day EMA is the faster and the 26-day EMA is the slower. Closing prices are used to form the moving averages. Usually, a 9-day EMA of MACD is plotted along side to act as a trigger line. A bullish crossover occurs when MACD moves above its 9-day EMA, and a bearish crossover occurs when MACD moves below its 9-day EMA. The histogram represents the difference between MACD and its 9-day EMA. The histogram is positive when MACD is above its 9-day EMA and negative when MACD is below its 9-day EMA.

MACD Bullish Signals

MACD generates bullish signals from three main sources:
1. Positive Divergence
2. Bullish Moving Average Crossover
3. Bullish Centerline Crossover

Positive Divergence

A Positive Divergence occurs when MACD begins to advance and the currency is still in a downtrend and makes a lower reaction low. MACD can either form as a series of higher Lows or a second Low that is higher than the previous Low. Positive Divergences are probably the least common of the three signals, but are usually the most reliable, and lead to the biggest moves.

Bullish Moving Average Crossover

A Bullish Moving Average Crossover occurs when MACD moves above its 9-day EMA, or trigger line. Bullish Moving Average Crossovers are probably the most common signals and as such are the least reliable. If not used in conjunction with other technical analysis tools, these crossovers can lead to whipsaws and many false signals. Bullish Moving Average Crossovers are used occasionally to confirm a positive divergence. A positive divergence can be considered valid when a Bullish Moving Average Crossover occurs after the MACD Line makes its second "higher Low".
Sometimes it is prudent to apply a price filter to the Bullish Moving Average Crossover to ensure that it will hold. An example of a price filter would be to buy if MACD breaks above the 9-day EMA and remains above for three days. The buy signal would then commence at the end of the third day.

Bullish Centerline Crossover

A Bullish Centerline Crossover occurs when MACD moves above the zero line and into positive territory. This is a clear indication that momentum has changed from negative to positive, or from bearish to bullish. After a Positive Divergence and Bullish Centerline Crossover, the Bullish Centerline Crossover can act as a confirmation signal. Of the three signals, moving average crossover are probably the second most common signals.