MACD (Moving Average Convergence Divergence) measures the gap between a fast and a slow moving average. The default settings subtract a 26-period EMA from a 12-period EMA to form the MACD line, then plot a 9-period EMA of that as the signal line. The histogram shows the distance between the two.
What it measures
When the fast average pulls away from the slow one, momentum is building; when they converge, momentum is fading. The MACD line above zero means the fast average is above the slow - a bullish backdrop - and below zero the reverse. The histogram is the early warning: it shrinks before the lines actually cross, hinting momentum is turning.
How to read it
Where traders get it wrong
Because MACD is built entirely from moving averages, it lags - and in a choppy range its crossovers fire constantly and lose. It shines in trending markets and struggles in consolidation. As with RSI, the most reliable MACD signal is divergence against price at a level, not the raw crossover taken mechanically on every occurrence.
An indicator confirms, it does not command. The signal is a reason to look, not an order to trade. Combine it with levels and the trend, and size every trade with the position size calculator so a false signal costs a small, fixed amount.
Test it before you trust it
Every indicator lags, because it is built from prices that have already printed. Add it to the chart in the simulator, trade the same setup with and without it across a large sample, and keep it only if it genuinely raises your expectancy - not because the signal looks convincing in hindsight.
MACD FAQ
How does the MACD indicator work?
MACD subtracts a slow moving average (default 26-period EMA) from a fast one (12-period EMA) to create the MACD line, then plots a 9-period average of that as the signal line. When the fast average moves away from the slow one, momentum is building; when they converge, it is fading. The histogram shows the gap between line and signal.
What is a MACD crossover?
A MACD crossover is when the MACD line crosses its signal line. A cross above the signal is a bullish signal and a cross below is bearish. Crossovers work best in trending markets - in a range they fire repeatedly and produce whipsaws, so they should be filtered by trend and backtested rather than traded blindly.
Is MACD better than RSI?
Neither is better - they measure momentum differently. RSI shows how stretched price is on a fixed 0-100 scale, while MACD shows the relationship between two moving averages and leans more on trend. Many traders use one, not both, since stacking two momentum tools rarely adds independent information.