What Is MACD?

What is MACD?

MACD (Moving Average Convergence Divergence) is a technical indicator that tracks the gap between two exponential moving averages to show trend direction and momentum strength together. Gerald Appel developed it in the late 1970s.

MACD has three parts: the MACD line, the signal line and the histogram, which shows the gap between the two as bars. For where the indicator fits in technical analysis overall, see the crypto technical analysis guide.

How Does It Work?

The logic is simple: when the short-term average pulls away from the long-term average quickly, the move is gaining speed; when the two averages come together, it is losing speed. That is where "convergence" and "divergence" in the name come from.

• MACD line above zero: the short-term average is above the long-term one; upward momentum.
• MACD line below zero: the short-term average is below the long-term one; downward momentum.
• Histogram growing: the gap between MACD and signal is widening; momentum is strengthening.
• Histogram shrinking: the gap is narrowing; momentum is fading.

The histogram often changes before the lines do. The MACD line can still be rising while the histogram starts shrinking, which says the advance continues but is slowing. Many analysts therefore watch the histogram's slope before waiting for a crossover.

History and Evolution

Gerald Appel introduced MACD in the late 1970s through his own publications and work, and later described it in detail in Technical Analysis: Power Tools for Active Investors (2005). The histogram was added later to make the gap between the two lines easier to read.

MACD spread first in stock and commodity markets and is now one of the most used indicators on currency and crypto charts as well. The PPO (Percentage Price Oscillator), developed to compare assets at different price levels, is MACD expressed in percentage terms.

Key Concepts

• EMA (exponential moving average): an average that gives more weight to recent data.
• Crossover: the MACD line crossing the signal line or the zero line.
• Zero line: the reference level at which the two averages are equal.
• Divergence: price and MACD making highs or lows in different directions.

Formula: How MACD Is Calculated

MACD line = EMA(12) − EMA(26)
Signal line = EMA(9) of the MACD line
Histogram = MACD line − Signal line

The standard setting is written as (12, 26, 9). In an EMA each new close is weighted by 2 / (n + 1): about 0.154 for the 12-period EMA and about 0.074 for the 26-period one. That is why the short average reacts to price faster.

Example (made-up numbers): if EMA(12) is 105 and EMA(26) is 100, the MACD line is 5. With a signal line of 4, the histogram is +1. If the next day MACD drops to 4.5 and the signal rises to 4.2, the histogram shrinks to +0.3: momentum is still positive but fading.

Because MACD is measured in the asset's price units, MACD values of assets at different price levels cannot be compared directly; PPO is used for that.

The (12, 26, 9) setting became common on daily charts and is still treated as the default. Some analysts try other settings in round-the-clock crypto markets, but a changed setting can no longer be compared with values from other sources. The same setting also works across timeframes: on a 4-hour chart 12 periods means two days, on a daily chart roughly two weeks of trading.

Crossovers and the Zero Line

• Signal-line crossover: the MACD line crossing above the signal line is read as momentum turning up; crossing below, as momentum turning down. These crossovers coincide with the histogram passing through zero.
• Zero-line crossover: the MACD line crossing zero means the 12- and 26-period averages have swapped places; it is a slower but clearer sign of a change in trend direction.

Crossovers on their own are not a reason to trade; repeated crossovers around the zero line point to an undecided market.

Divergence

If price makes a new high while MACD makes a lower high, that is bearish divergence; if price makes a new low while MACD makes a higher low, that is bullish divergence. Both show the current move losing momentum. Divergence does not time a reversal and can persist for a long time in strong trends.

Lag: Why MACD Arrives Late

Because it is built from moving averages, MACD is a lagging indicator: it turns after price turns. In fast, sharp moves a crossover can appear after much of the move has already happened. Shortening the periods reduces lag but increases false readings; it is a trade-off. Lag is better seen as the price of filtering noise than as a flaw: MACD is built to capture trends that last weeks, not moves that last a few candles.

Trend or Momentum? Where MACD Fits

MACD carries both trend and momentum information: its position relative to zero describes trend direction, and the histogram describes acceleration. That is why it is often seen as a bridge between the two families. It is used alongside the moving average (EMA) and Supertrend on the trend side, RSI on the momentum side and Bollinger Bands on the volatility side. In sideways markets the two averages run very close together, so MACD can produce frequent, meaningless crossovers; in those periods support and resistance levels tend to explain more.

Live Examples: The MACD Row

COINOTAG technical analysis pages calculate MACD with the standard (12, 26, 9) setting and show its direction among the indicator groups. On the crypto side, see Bitcoin technical analysis and support and resistance levels and Ethereum technical analysis; for stocks and commodities, NVIDIA technical analysis and Gold (XAU) technical analysis.

For a combined technical view across many assets, use the crypto technical summary table and the stocks and commodities technical summary.

Practical Example

Scenario (made-up numbers): an asset moves sideways between $1.00 and $1.20 for weeks while MACD keeps flipping around the zero line. The price then breaks above $1.20 on rising trading volume, the MACD line crosses above the signal line and soon moves above zero.

• The crossovers during the sideways phase show MACD's limit in that kind of market.
• A crossover that comes with the breakout, followed by MACD moving above zero, is read as momentum turning up.
• This reading does not guarantee direction; analysts also watch whether the broken level holds and how candlestick closes develop.

Related Terms and Next Steps

To read MACD well, it helps to understand how an EMA is calculated, how RSI measures momentum, and how support and resistance levels are read together with MACD signals.