Plain-English definition
MACD compares a faster EMA with a slower EMA, then smooths that difference with a signal line.
What it measures
Trend direction, momentum change, and expansion or contraction between averages.
Formula
MACD line = fast EMA − slow EMA. Signal line = EMA of the MACD line. Histogram = MACD line − signal line.
How to read it
A positive MACD line means the fast average is above the slow average. Histogram expansion shows increasing separation, not guaranteed continuation.
Common signals
- Signal-line cross
- Zero-line cross
- Histogram expansion or contraction
- Divergence
Best market conditions
Sustained directional moves and developing momentum transitions.
Weak market conditions
Sideways markets with repeated crosses and fast reversals where lag becomes expensive.
Default settings
12 fast, 26 slow, and 9 signal are the conventional settings.
Alternative settings
Faster combinations respond earlier with more noise; slower combinations emphasize broader trends.
Repainting and confirmation
Standard bar-close MACD does not repaint. Intrabar and higher-timeframe implementations require care.
Common mistakes
- Taking every cross
- Ignoring distance to invalidation
- Confusing lag with reliability
- Optimizing settings to one sample
Example use
Use histogram expansion to confirm that an already-defined directional setup is gaining momentum.
Strategy ideas worth testing
- Zero-line regime filter
- Histogram acceleration
- MACD plus STC comparison
- Trend-filtered crosses
Complementary indicators
Summary verdict
A clear trend-momentum baseline. Its transparency is a strength; lag and range noise are the cost.
Frequently asked questions
Why is MACD late?+
It is derived from moving averages, so confirmation follows price.
Does MACD repaint?+
A standard closed-bar MACD does not.
Is the histogram an entry signal?+
Not by itself. It describes the distance between MACD and its signal line.