Simple Moving Average: How to Use this Popular Indicator

The Simple Moving Average (SMA) is one of the most widely used tools in technical analysis, helping investors smooth price data over a specified period to identify a stock’s overall trend. It is calculated by adding the closing prices of a stock over a set number of days and then dividing by that number.

For example, a 50-day SMA sums up the last 50 closing prices and divides them by 50, creating an average that moves over time with each new data point.

Traders often use tools like a stock screener with custom triggers to identify stocks interacting with key SMA levels.

How SMA Indicates Stock Value

The SMA is commonly used to gauge whether a stock is over- or undervalued by comparing its current price to its historical price trend. Here’s how it works:

Short vs. Long Period SMA

SMAs are categorized based on the length of the period they cover. Shorter periods, like the 20-day SMA, are more sensitive to recent price changes and can quickly indicate short-term momentum, while longer periods like the 200-day SMA provide a clearer view of a stock’s long-term trend.

Crossing Signals

Investors often use multiple SMAs, such as a 50-day and a 200-day SMA, to watch for “crossovers.” If a shorter SMA (e.g., 50-day) crosses above a longer SMA (e.g., 200-day), it’s known as a Golden Cross indicator, typically viewed as a bullish signal suggesting potential undervaluation.

Conversely, when a shorter SMA crosses below a longer SMA, it’s called a “Death Cross,” which often indicates bearish momentum and possible overvaluation.

These events can be tracked automatically using customizable stock alerts.

SMA and Current Price

Comparing the current stock price to its simple moving average can also reveal insights. If the stock is trading above its long-term SMA (e.g., 200-day SMA), it could indicate a potential overvaluation if the price significantly deviates from the SMA. Conversely, a stock trading below its SMA may be undervalued if it is expected to revert to the mean.

Limitations and Considerations

The SMA is useful for tracking trends, but it does not incorporate stock-specific fundamentals (like earnings or cash flow) or broader market influences. Additionally, since SMAs lag behind real-time prices, they may miss sudden reversals. Therefore, combining SMA with other indicators or fundamentals provides a more holistic view for investment decisions.

The Bottom Line

Using SMA as a guide for potential undervaluation or overvaluation can be an effective strategy for identifying stock price trends. However, SMA works best in conjunction with other tools, providing a broader context that helps retail investors avoid “false signals” and make more informed investment decisions.