A Simple Moving Average, or SMA, is a technical indicator that calculates the average closing price of an asset over a selected number of periods. Traders use the SMA to smooth price data, identify trend direction, and track dynamic support or resistance on a chart.
What Is a Simple Moving Average (SMA)?
A Simple Moving Average is the average closing price of an asset over a fixed number of periods. A 20 period SMA, for example, adds the last 20 closing prices and divides the total by 20.
The SMA belongs to the Moving Average (MA) family. The SMA is the simplest member of that family because every closing price in the selected period carries the same weight.
Traders use the SMA to smooth price fluctuations, reducing noise on the chart so the underlying trend direction is easier to read. Understanding what the SMA is and where it sits in the Moving Average family sets up the next question: what specific traits make it behave the way it does.
Core Characteristics of the SMA
The SMA has three core traits: equal weighting, lagging behavior, and price smoothing.
Smooths Price
The SMA smooths price by averaging several closes into one line. This averaging process removes part of the short-term noise from the chart, making the broader price movement easier to follow than the raw candles alone.
Equal Weighting
Equal weighting means each closing price affects the SMA by the same amount. The newest close and the oldest close inside the selected period carry identical importance in the calculation, the SMA does not favor recent price action over older price action.
Lagging Indicator
The SMA is a lagging indicator because its calculation uses past prices only. The SMA line reacts after price has already moved, not before, since it has no mechanism for weighting or anticipating new data.
These three traits show equal weighting, lag, and smoothing are a direct result of how the SMA is calculated. The formula itself makes that relationship explicit.
How Does Simple Moving Average (SMA) in Trading Work?
The SMA is calculated by adding the selected closing prices and dividing the total by the number of periods.
SMA Formula
SMA = (P₁ + P₂ + P₃ + ... + Pₙ) / n
In this formula, P represents each closing price and n represents the number of periods. A 20 period SMA uses the last 20 closing prices; a 200 period SMA uses the last 200.
Step-by-Step Example Calculation
The clearest way to see how the SMA formula works is to walk through it with real numbers.
Assume a 5 period SMA uses these closing prices: 10, 11, 12, 11, 14.
Step 1: Add the five closing prices. 10 + 11 + 12 + 11 + 14 = 58
Step 2: Divide the total by 5. 58 / 5 = 11.6
The 5 period SMA is 11.6.
Updated example: If the next closing price is 15, the oldest price (10) drops out of the calculation. The new set of five prices becomes: 11, 12, 11, 14, 15.
Step 3: Add the updated five prices. 11 + 12 + 11 + 14 + 15 = 63
Step 4: Divide the new total by 5. 63 / 5 = 12.6
The new 5 period SMA is 12.6.
Step 1: Add the five closing prices.
10 + 11 + 12 + 11 + 14 = 58
Step 2: Divide the total by 5.
58 / 5 = 11.6
The 5 period SMA is 11.6
If the next closing price is 15, the oldest price, which is 10, drops out. The new set becomes:
Step 3: Add the updated five prices.
11 + 12 + 11 + 14 + 15 = 63
Step 4: Divide the new total by 5.
63 / 5 = 12.6
The new 5 period SMA is 12.6
That rolling update is why the average moves across the chart. Each new candle adds one price, and the oldest price drops out.
This rolling update by adding the newest close and dropping the oldest. This is why the SMA moves across the chart as new candles form. Knowing how the SMA is built explains what it can and can't tell a trader once it's applied to a live chart, which is the next question.
How to Use the Simple Moving Average (SMA)?
Traders use the SMA to judge trend direction, treat it as dynamic support or resistance, and read crossover signals between two SMAs.
Identifying Trend Direction
The SMA shows trend direction through its slope and its position relative to price. A rising SMA with price trading above the line typically supports an uptrend view. A falling SMA with price trading below the line typically supports a downtrend view. A flat SMA often signals weak momentum or a ranging market rather than a clear trend.
Support and Resistance
The SMA can act as dynamic support or resistance. In an uptrend, price may pull back into a rising SMA, find support there, and rebound upward. In a downtrend, price may rally into a falling SMA, meet resistance there, and reject lower.
SMA Crossover Signals (Golden Cross and Death Cross)
A crossover happens when one SMA crosses another SMA of a different period. Traders use crossovers to judge a possible shift in trend strength.
A Golden Cross happens when a shorter SMA crosses above a longer SMA, signaling strengthening momentum as price consistently closes above the average.
Golden Cross: Simple Moving Average. Black is 5 days SMA, and Blue is 20 days SMA.
Golden Cross: Simple Moving Average. Black is 5 days SMA, and Blue is 20 days SMA.
A Death Cross happens when a shorter SMA crosses below a longer SMA, signaling weakening momentum, after which price tends to treat the longer SMA as dynamic resistance.
Death Cross: Simple Moving Average. Black is 5 days SMA, and Blue is 20 days SMA.
Death Cross: Simple Moving Average. Black is 5 days SMA, and Blue is 20 days SMA.
Naming the Golden Cross and Death Cross explains what a crossover signals — the next step is seeing what acting on that signal actually looks like in a single, worked trade.
A Worked SMA Crossover Trade Example
A Golden Cross can be used as a long entry signal, and the following Death Cross can be used as the exit, the example below walks through this using hypothetical, round numbers for illustration only.
Assume Stock ABC is trading at 100 when its 5 day SMA crosses above its 20 day SMA it a Golden Cross. A trader following this signal enters long at 100. Over the following weeks, price trends higher until the 5 day SMA crosses back below the 20 day SMA it a Death Cross, at a price of 118. Closing the position at that point produces an illustrative gain of 18 points on this single, hypothetical trade.
This example shows the mechanics of a crossover based entry and exit only, it is not a performance claim, a backtested result, or a recommendation. In a ranging market, the same rule can generate a Golden Cross and Death Cross in quick succession with little or no gain between them, which is why crossover signals are usually combined with the risk management and confluence practices covered later in this article.
Common SMA Periods and What They Mean
Different SMA periods suit different trading horizons. Shorter periods react faster to price and longer periods filter more noise.
The best period depends on the trader's time frame and objective. Once a period is chosen, the next step is plotting it with setting up the SMA correctly.
How to Add the SMA Indicator on MT4/MT5
The Simple Moving Average is added on MT4/MT5 through the platform's built-in Trend indicator list, with the calculation method set explicitly to Simple.
Open the chart of the instrument to plot the SMA on.
Go to Insert > Indicators > Trend > Moving Average.
In the Moving Average settings window, set the Period field to the SMA length (for example, 20 or 200).
Set the MA Method field to Simple, MT4/MT5 Moving Average tool also supports Exponential, Smoothed, and Linear Weighted methods, so this step is what specifically plots an SMA rather than another type of moving average.
Confirm Apply to is set to Close, since the SMA is calculated from closing prices, then select OK to plot the line on the chart.
With the SMA correctly plotted, the next question is how to read it alongside other tools on the same chart.
For a deeper understanding of your charting environment, explore our guides on mastering the MetaTrader 4 interface and navigating the MetaTrader 5 workspace.
Using SMA with Other Indicators
The SMA works better when combined with a second, independent signal that a practice traders call confluence.
Useful confluence for the SMA includes a breakout from a chart pattern that holds above the SMA, RSI confirming momentum in the same direction, MACD confirming trend continuation, and volume expanding on a move away from the SMA. A practical approach is to use the SMA to define market bias first, then use a confluence indicator to judge entry quality.
Risk Management When Using the SMA
The SMA is a structure tool, not a self sufficient trading system, so its signals need a defined stop loss method to be used safely.
An SMA should not be used as the exact stop loss level, because price often trades slightly above or below the line before a trend resumes. A more reliable method places the stop beyond the price structure that would prove the trade wrong. In a long setup, that typically means below the recent swing low and below the relevant SMA. In a short setup, it typically means above the recent swing high and above the relevant SMA.
The SMA is a lagging indicator, and a late signal becomes less reliable in a sideways market, during a volatility spike, or when it conflicts with higher timeframe structure. For this reason, the SMA is best used as a dynamic reference for trend and support/resistance, not as a standalone trading plan.
Advantages and Limitations of the SMA
The SMA smooths price data and makes trend direction easier to read, which is why traders use it as a basic trend filter but its main limitation is lag, since it reacts more slowly than price and more slowly than faster reacting averages when the market changes quickly.
Advantages
Multi-purpose: the SMA overlays for trend reading, momentum context, and dynamic support/resistance.
Easy to interpret: price relative to the SMA gives quick trend context.
Reduces noise: the SMA smooths chaotic price data, making the chart easier to read.
Limitations
Slow reaction: the SMA line updates only after the price has already moved.
Weak in sideways markets: repeated SMA crosses in a range carry little useful information.
SMA vs EMA: What Is the Difference?
The main difference between the SMA and the Exponential Moving Average (EMA) is weighting: the SMA gives equal weight to every price in the period, while the EMA gives more weight to recent prices.
This weighting difference is the direct cause of how each line behaves. The SMA is smoother and slower to react, while the EMA is faster and more sensitive to short-term price changes, as a result of its formula, not a separate design choice. A third type, the Weighted Moving Average (WMA), sits between the two, it also weights recent prices more heavily than older ones, but does so on a linear rather than exponential scale, making it less reactive than the EMA but more reactive than the SMA.
For a full breakdown of how the EMA is calculated and used on its own, see TMGM's guide to the Exponential Moving Average (EMA) indicator.
Simple Moving Average FAQ
Which Is Better, EMA or SMA?
Neither average is always better. The SMA is better for smoother trend reading, while the EMA is better for faster reaction to recent price changes.
What Does 50 SMA Mean?
A 50 SMA is the average closing price of the last 50 periods. Traders use the 50 SMA to judge intermediate trend direction and to track dynamic support or resistance.
Should Traders Use 200 EMA or 200 SMA?
The choice depends on the goal. A 200 SMA gives a smoother long-term trend filter, while a 200 EMA reacts faster to recent price changes.
Should I Use SMA or EMA for a 20 or 50 Period Setting?
Both the SMA and EMA can be set to 20 or 50 period lengths, the SMA version will be smoother and slower to react, while the EMA version will track price more closely.
Put Simple Moving Average Analysis Into Practice
TMGM MetaTrader platforms let traders configure the Simple Moving Average (SMA) by period, applied price, and timeframe. Use consistent settings to identify clear trend directions, test your observations against real price structure, and always define your risk before acting.
Ready to put your SMA strategy to the test? Open a live account to start your CFD trading journey today, or open a demo account to practice risk-free.
