This page is about the Simple Moving Average, the most common and popular of the moving averages. If you are interested in other versions of the moving average please select the links below:
The Simple Moving Average is arguably the most popular technical analysis tool used by traders. The Simple Moving Average (SMA) is used mainly to identify trend direction, but is commonly used to generate buy and sell signals. The SMA is an average, or in statistical speak - the mean. An example of a Simple Moving Average is presented below:
The chart below of the Dow Jones Industrial Average exchange traded fund (DIA) shows a 20-day Simple Moving Average acting as support for prices.

When price is in an uptrend and subsequently, the moving average is in an uptrend, and the moving average has been tested by price and price has bounced off the moving average a few times (i.e. the moving average is serving as a support line), then buy on the next pullbacks back to the Simple Moving Average.
A Simple Moving Average can serve as a line of resistance as the chart of the DIA shows:

At times when price is in a downtrend and the moving average is in a downtrend as well, and price tests the SMA above and is rejected a few consecutive times (i.e. the moving average is serving as a resistance line), then buy on the next rally up to the Simple Moving Average.
The examples above have been only using one Simple Moving Average; however, traders often use two or even three Simple Moving Averages. The advantages to using more than one Simple Moving Average is discussed on the next page.
Moving average crossovers are a common way traders use Moving Averages. A crossover occurs when a faster Moving Average (i.e. a shorter period Moving Average) crosses either above a slower Moving Average (i.e. a longer period Moving Average) which is considered a bullish crossover or below which is considered a bearish crossover.
The chart below of the S&P Depository Receipts Exchange Traded Fund (SPY) shows the 50-day Simple Moving Average and the 200-day Simple Moving Average; this Moving Average pair is often looked at by big financial institutions as a long range indicator of market direction:

Note how the long-term 200-day Simple Moving Average is in an uptrend; this is a signal that the market is quite strong. Generally, a buy signal is established when the shorter-term 50-day SMA crosses above the 200-day SMA and contrastly, a sell signal is indicated when the 50-day SMA crosses below the 200-day SMA.
In the chart above of the S&P 500, both buy signals would have been extremely profitable, but the one sell signal would have caused a small loss. Keep in mind, that the 50-day, 200-day Simple Moving Average crossover is a very long-term strategy.
For those traders that want more confirmation when they use Moving Average crossovers, the 3 Simple Moving Average crossover technique could be used. An example of this is shown in the chart below of Wal-Mart (WMT) stock:

The 3 Simple Moving Average method is usually interpreted as follows:
There are numerous variants and methodologies for using the 3 Simple Moving Average crossover method, some are provided below:
A Moving Average crossover technique that uses 8+ Moving Averages (exponential) is the Moving Average Exponential Ribbon Indicator (see: Exponential Ribbon).
Moving Average crossovers are important tools in a traders toolbox. In fact crossovers are included in the most popular technical indicators including the Moving Average Convergence Divergence (MACD) indicator (see: MACD). Other moving averages deserve careful consideration in a trading plan:
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