The MACD: lines, signal and histogram

The MACD (Moving Average Convergence Divergence) was created in the late 1970s and remains one of the most widely displayed indicators on charts. The name is intimidating, but the principle is simple: it turns the gap between two moving averages into an easy-to-read line. In doing so, it combines trend information with momentum information.

The three components

Below your chart, the MACD usually shows two lines and vertical bars. Each element has a specific role, and all of them come from the same starting calculation.

• The MACD line: the difference between the 12 EMA and the 26 EMA of closing prices. Positive when the fast average is above the slow one, negative in the opposite case.
• The signal line: a 9 EMA of the MACD line itself. It is a smoothed, slightly delayed version of the MACD.
• The histogram: the difference between the MACD line and the signal line, drawn as bars around zero.

The 12, 26 and 9 settings

The default values are 12, 26 and 9. There is nothing magic about them, but they have become the standard on every platform, and that is exactly what makes them useful: everyone is looking at the same thing. You can shorten the periods for a more responsive MACD, at the cost of more frequent and less reliable signals.

Crossovers

The MACD gives two types of crossover. The first, and most followed, is the MACD line crossing its signal line. When the MACD moves above the signal, momentum turns bullish; below it, bearish. On the histogram, this is the moment the bars flip from one side of zero to the other.

The second is the zero-line crossover. When the MACD turns positive, the 12 EMA has just moved above the 26 EMA: it is exactly a moving average crossover, like the one you saw in the previous lesson. This signal is slower, but it confirms a more solid change of trend.

Reading the histogram

The histogram is often the most useful part. It does not just tell you which way momentum is going, it tells you whether it is speeding up or slowing down. Positive bars getting taller show a rally gaining speed. Positive bars getting shorter show a rally losing speed, even if price keeps rising. That slowdown often comes before the lines cross.

Be careful not to over-interpret: a shrinking histogram signals a slowdown, not a reversal. A trend can slow, rest for a few candles, then take off again even harder.

Using the MACD well

1. First identify the trend on the higher timeframe, using the structure of highs and lows.
2. Only take MACD-signal crossovers in the direction of that trend.
3. Favour bullish crossovers that happen below the zero line in an uptrend: they often mark the end of a pullback.
4. Be wary of repeated crossovers around zero: they give away a market with no direction.
5. Place your stop based on price structure, never based on the MACD.

A point that is often misunderstood: the MACD's value depends on the asset's price. On EUR/USD it is measured in ten-thousandths; on the DAX, in tens of points; on gold, in dollars. So you cannot compare the MACD of two different markets, or set a universal "high MACD" threshold. What matters is its position relative to zero and to its signal line, and how the histogram evolves on the same chart.

Another useful habit: check the MACD on the higher timeframe before following a crossover on the lower one. A bullish crossover on H1 while the D1 MACD is clearly negative and still falling is very likely to be nothing more than a short-lived technical bounce.

The MACD is also used to spot divergences between price and momentum, a more advanced reading you will discover at the end of this level. For now, practise watching the histogram on gold or the DAX on H4 and noting when it starts to shrink before a pullback.