MACD: Trend and Momentum in One Indicator
MACD combines two moving averages to show both trend direction and momentum strength. Learn how to read the MACD line, signal line, and histogram, and how to use crossovers and divergence effectively.
MACD (Moving Average Convergence Divergence), created by Gerald Appel in the 1970s, is one of the most widely used technical indicators. It tells you two things at once: the direction of the trend and how strong the momentum behind it is.
The Three Components of MACD
| Component | What It Is | How Plotted |
|---|---|---|
| MACD Line | 12 EMA minus 26 EMA | The faster line |
| Signal Line | 9 EMA of the MACD line | The slower, smoothed line |
| Histogram | MACD line minus Signal line | Bars showing the gap between the two lines |
When the 12 EMA is above the 26 EMA, the MACD line is positive. When below, it is negative. Crossings of the zero line are broad trend signals; crossings of the signal line are entry signals.
MACD Crossovers
| Crossover | Meaning |
|---|---|
| MACD crosses above signal line | Bullish — momentum shifting upward |
| MACD crosses below signal line | Bearish — momentum shifting downward |
| MACD crosses above zero | Broader uptrend confirmed |
| MACD crosses below zero | Broader downtrend confirmed |
Location of the Crossover Matters
A bullish crossover that happens above the zero line is stronger than one below zero. A crossover below zero means you are turning bullish while momentum is still net negative.
Reading the Histogram
The histogram is the most forward-looking part of MACD. Growing bars mean momentum is accelerating. Shrinking bars — even while still positive — mean momentum is weakening, often before the actual crossover happens.
Watch the Histogram Shrink
Histogram bars getting shorter is an early warning that the current move is losing steam. This gives you advance notice before the MACD/signal crossover occurs.
MACD Divergence
Bearish MACD Divergence
A stock rallies to 1,500 with MACD at 8.5. It pulls back then rallies again to 1,580 (new price high), but MACD only reaches 6.2. Price is higher; MACD is lower. The move is running out of fuel and the stock reverses shortly after.
MACD Limitations
- It is lagging — crossovers often happen after much of the move is already done
- In sideways, choppy markets it generates many false signals
- The default 12/26/9 settings work best on daily charts — shorter timeframes produce noisier signals
- Always combine MACD with trend context and price structure
Key Takeaways
- MACD = 12 EMA minus 26 EMA. The signal line is a 9 EMA of the MACD line.
- A MACD line crossing above the signal line is bullish; crossing below is bearish.
- The histogram shows the gap between MACD and signal lines — it leads the crossover.
- MACD divergence is a reliable early warning of trend weakness.
- MACD is lagging — use it to confirm trends, not to time exact entries.