Simple Moving Average (SMA) &Exponential Moving Average (EMA) Explained

A simple moving average (SMA) is the simplest type of moving average in forex analysis (DUH!). Basically, a simple moving average is calculated by adding up the last “X” period’s closing prices and then dividing that number by X.

Confused???
Don’t worry, we’ll make it crystal clear.

Calculating the Simple Moving Average (SMA)

If you plotted a 5 period simple moving average on a 1-hour chart, you would add up the closing prices for the last 5 hours, and then divide that number by 5. Voila! You have the average closing price over the last five hours! String those average prices together and you get a moving average!
If you were to plot a 5-period simple moving average on a 10-minute currency chart, you would add up the closing prices of the last 50 minutes and then divide that number by 5.
If you were to plot a 5 period simple moving average on a 30 minute chart, you would add up the closing prices of the last 150 minutes and then divide that number by 5.
If you were to plot the 5 period simple moving average on the 4 hr. chart… Okay, okay, we know, we know. You get the picture!
Most charting packages will do all the calculations for you. The reason we just bored you (yawn!) with a “how to” on calculating simple moving averages is because it’s important to understand so that you know how to edit and tweak the indicator.
Understanding how an indicator works means you can adjust and create different strategies as the market environment changes.
Now, as with almost any other forex indicator out there, moving averages operate with a delay. Because you are taking the averages of past price history, you are really only seeing the general path of the recent past and the general direction of “future” short term price action.

Disclaimer: Moving averages will not turn you into Ms. Cleo the psychic!
Here is an example of how moving averages smooth out the price action.

On chart above, we’ve plotted three different SMAs on the 1-hour chart of USD/CHF. As you can see, the longer the SMA period is, the more it lags behind the price.
Notice how the 62 SMA is farther away from the current price than the 30 and 5 SMAs.
This is because the 62 SMA adds up the closing prices of the last 62 periods and divides it by 62. The longer period you use for the SMA, the slower it is to react to the price movement.
The SMAs in this chart show you the overall sentiment of the market at this point in time. Here, we can see that the pair is trending.
Instead of just looking at the current price of the market, the moving averages give us a broader view, and we can now gauge the general direction of its future price. With the use of SMAs, we can tell whether a pair is trending up, trending down, or just ranging.
There is one problem with the simple moving average: they are susceptible to spikes. When this happens, this can give us false signals. We might think that a new currency trend may be developing but in reality, nothing changed.
In the next lesson, we will show you what we mean, and also introduce you to another type of moving average to avoid this problem.

As we said in the previous lesson, simple moving averages can be distorted by spikes. We’ll start with an example.
Let’s say we plot a 5-period SMA on the daily chart of EUR/USD.

The closing prices for the last 5 days are as follows:
Day 1: 1.3172
Day 2: 1.3231
Day 3: 1.3164
Day 4: 1.3186
Day 5: 1.3293
The simple moving average would be calculated as follows:
(1.3172 + 1.3231 + 1.3164 + 1.3186 + 1.3293) / 5 = 1.3209
Simple enough, right?
Well what if there was a news report on Day 2 that causes the euro to drop across the board. This causes EUR/USD to plunge and close at 1.3000. Let’s see what effect this would have on the 5 period SMA.
Day 1: 1.3172
Day 2: 1.3000

Day 3: 1.3164
Day 4: 1.3186
Day 5: 1.3293
The simple moving average would be calculated as follows:
(1.3172 + 1.3000 + 1.3164 + 1.3186 + 1.3293) / 5 = 1.3163
The result of the simple moving average would be a lot lower and it would give you the notion that the price was actually going down, when in reality, Day 2 was just a one-time event caused by the poor results of an economic report.
The point we’re trying to make is that sometimes the simple moving average might be too simple. If only there was a way that you could filter out these spikes so that you wouldn’t get the wrong idea. Hmm… Wait a minute… Yep, there is a way!
It’s called the Exponential Moving Average!
Exponential moving averages (EMA) give more weight to the most recent periods. In our example above, the EMA would put more weight on the prices of the most recent days, which would be Days 3, 4, and 5.
This would mean that the spike on Day 2 would be of lesser value and wouldn’t have as big an effect on the moving average as it would if we had calculated for a simple moving average.
If you think about it, this makes a lot of sense because what this does is it puts more emphasis on what traders are doing recently.

Exponential Moving Average (EMA) and Simple Moving Average (SMA) Side By Side

Let’s take a look at the 4-hour chart of USD/JPY to highlight how a simple moving average (SMA) and exponential moving average (EMA) would look side by side on a chart.

Notice how the red line (the 30 EMA) seems to be closer price than the blue line (the 30 SMA). This means that it more accurately represents recent price action. You can probably guess why this happens.
It’s because the exponential moving average places more emphasis on what has been happening lately. When trading, it is far more important to see what traders are doing NOW rather what they were doing last week or last month.