MACD Indicator: An Overview
Introduction
Created by Gerald Appel in the late 1970s, the Moving Average Convergence Divergence (MACD) indicator is a popular technical analysis tool traders use worldwide. Appel, a renowned trader and technical analyst, developed the MACD to better understand price trends and potential reversals in financial markets.

Understanding the MACD Indicator
The Moving Average Convergence Divergence (MACD) is a momentum oscillator widely used in technical analysis to evaluate the relationship between two moving averages of a security’s price. The MACD is designed to reveal changes in a trend’s strength, direction, and duration in a financial instrument’s price, providing valuable insights for traders and investors.
Momentum Oscillator
As a momentum oscillator, the MACD measures the speed and strength of price movements over a specific period. It helps traders identify potential trend reversals, continuation, and overbought or oversold market conditions. By doing so, the MACD assists traders in making informed decisions about when to enter or exit a trade.
Exponential Moving Averages (EMAs)
The MACD is based on the difference between two Exponential Moving Averages (EMAs) of a security’s price. EMAs assign greater weight to the most recent data, making them more sensitive to recent price changes than Simple Moving Averages (SMAs). The most common settings for the MACD involve a 12-period EMA (shorter-term) and a 26-period EMA (longer-term).
Convergence and Divergence
The MACD’s primary function is to identify instances of convergence and divergence between the two EMAs. Convergence occurs when the moving averages move closer together, indicating a potential trend weakening. Divergence, on the other hand, happens when the moving averages move further apart, signaling a possible strengthening of the trend.
Trend Strength and Direction
The MACD is particularly useful in identifying the strength and direction of a trend. When the MACD line is above the signal line and moving upward, it suggests a bullish trend with increasing momentum. Conversely, when the MACD line is below the signal line and moving downward, it indicates a bearish trend with decreasing momentum.
Duration of the Trend
While the MACD does not provide exact information on the duration of a trend, it can help traders estimate how long a trend might last by observing the slope and distance between the MACD and signal lines. A steeper slope and a widening gap between the lines may imply a more prolonged and sustained trend.
Components of the MACD
The MACD consists of three main components:
- MACD Line: This line is the difference between two exponential moving averages (EMAs) of a security’s price, typically 12-day and 26-day EMAs.
- Signal Line: This line is an EMA of the MACD line, typically a 9-day EMA.
- MACD Histogram: This histogram represents the difference between the MACD and signal lines.
Calculating the MACD
Calculating the MACD is a straightforward process involving the following steps:
- Compute the 12-period EMA of the security’s price.
- Compute the 26-period EMA of the security’s price.
- Subtract the 26-period EMA from the 12-day EMA to obtain the MACD line.
- Compute the 9-period EMA of the MACD line, which becomes the signal line.
- Subtract the signal line from the MACD line to create the MACD histogram.
The formula for the MACD can be expressed as follows:
MACD = 12-period EMA – 26-period EMA
This formula calculates the MACD line, representing the difference between the short-term (12-period) and long-term (26-period) EMAs of the security’s price. The signal line and MACD histogram are then derived from the MACD line using the abovementioned steps.
Example scanners and strategies that use MACD Indicator
How to Interpret the MACD Indicator
Signal Line Crossovers
Bullish and Bearish Crossovers
Signal line crossovers are one of the primary ways to interpret the MACD indicator. A bullish crossover occurs when the MACD line crosses above the signal line, which is often considered a buy signal. Conversely, a bearish crossover occurs when the MACD line crosses below the signal line, indicating a potential sell signal.
Divergences
Positive and Negative Divergences
Divergences occur when the price of a security and the MACD indicator move in opposite directions. A positive divergence transpires when the price makes a new low while the MACD forms a higher low, suggesting a potential reversal to the upside. Conversely, a negative divergence arises when the price records a new high while the MACD creates a lower high, indicating a possible reversal to the downside. Traders often use divergences as early warning signs of potential trend reversals.
MACD Histogram
Histogram Interpretation
The MACD histogram offers insight into the relationship between the MACD and signal lines. When the histogram is above zero, it signifies that the MACD line is above the signal line, indicating bullish momentum. Conversely, when the histogram is below zero, the MACD line is below the signal line, suggesting bearish momentum. Additionally, when the histogram increases or decreases in height, it demonstrates that the gap between the MACD and signal lines is widening, reflecting a strengthening trend. A shrinking histogram indicates that the gap between the two lines is narrowing, signaling a weakening trend.
Using the MACD in Trading Strategies
Combining MACD with Other Indicators
To increase the effectiveness and reduce the likelihood of false signals, traders often combine the MACD with other technical indicators, such as the Relative Strength Index (RSI) or the Bollinger Bands. By employing multiple indicators, traders can confirm the signals generated by the MACD and increase the probability of successful trades.
Adjusting MACD Settings
The default settings for the MACD (12, 26, 9) may not be suitable for all trading strategies or timeframes. Traders can adjust these settings to suit their specific needs or preferences better. For example, by increasing the periods used for the EMAs, traders can create a more conservative MACD that generates fewer signals but may be more reliable. Conversely, by reducing the periods, traders can make a more aggressive MACD that provides more frequent signals, albeit with an increased risk of false signals.
Limitations of the MACD Indicator
As with any technical indicator, the MACD has its limitations. First, the MACD is a lagging indicator, meaning that it relies on historical price data and may not always predict future price movements accurately. Second, the MACD can generate false signals, especially in sideways or range-bound markets, leading to potential losses. Lastly, the MACD’s effectiveness can vary depending on the security being analyzed and the timeframe being used, making it essential for traders to understand the nuances of the indicator and adjust its settings accordingly.
MACD and Its Relationship to the PPO
The Percentage Price Oscillator (PPO) is another momentum oscillator that shares similarities with the MACD. The PPO calculates the difference between two moving averages of a security’s price as a percentage. This allows for easier comparisons between different securities, regardless of their price levels. The PPO is calculated using the following formula:
PPO = (Shorter EMA - Longer EMA) / Longer EMA * 100
The interpretation of the PPO is similar to that of the MACD, with signal line crossovers, divergences, and histograms providing insights into potential trend reversals and momentum shifts. However, the PPO’s percentage-based calculation makes it more suitable for comparing securities with differing prices or analyzing an individual security across various timeframes.
The Bottom Line
The MACD indicator is a popular and versatile tool in technical analysis, offering insights into trend strength, direction, and potential reversals. By understanding the components and interpretations of the MACD, traders can develop more informed trading strategies. However, it is crucial to recognize the limitations of the MACD and consider combining it with other technical indicators to increase the likelihood of successful trades. As with any trading strategy, traders must manage risk and develop a comprehensive understanding of the financial instruments they trade to maximize their chances of success.