RSI in Forex Trading

by : Andrew Shiveley

If you trade the foreign currency market professionally or as a way to earn more money at home, there is a good chance that you have devised a trading system for yourself that creates buy and sell signals. If you do not have a trading system then you should probably consider creating one (or at least keeping a notebook of your trades), but even the best trading systems can sometimes give false signals.

While it is possible to create a technical trading system using anything from moving average crosses to candlestick formations that will run entirely on autopilot, it is also good to throw human supervision into the mix since an autopilot trading system may not be able to take into account things like prevailing market sentiment. Remember that it is *people* and not computers that create market movements, and all these people make trading decisions based upon their emotions and where they think the market will be headed next.

One of the ways to make sure that the trading signals that you receive are valid is to use a momentum indicator in conjunction with your charts and signals. One of the most popular momentum indicators is called the Relative Strength Index (RSI), and the most typical settings for this indicator is either a 14 or 21 day period setting. This indicator sits above or below actual price data, and it should be available on literally every charting package out there. The reason you will probably want to keep your RSI set to either a 14 or 21 day period is that most other traders will be using these settings as well, making the data that the RSI puts out a kind of "self-fulfilling prophecy" since so many other traders will be following it.

In this instance, the term "momentum" can best be defined as the speed at which prices are moving, and momentum indicators like the RSI will reveal whether the market is considered to be overbought or oversold. The best way to understand what an overbought or oversold market means is that prices have been going up or down too fast relative to recent prior activity.

On the RSI, you will be given a value ranging from 0-100. Any level above 70 will typically mean that the market is considered to be overbought, and a level below 30 will mean that the market is considered to be oversold. For you to understand the way that you can use this data in order to determine how valid your trading signals are, I will give an example of a possible trade.

Let's say that your trading system is based on holding open positions from anywhere from two hours up to two days. This falls a bit in between the categories of day trading and swing trading, but since it still tends towards the shorter side then you would probably want to use the shorter period of 14 on your RSI indicator. You can see on your chart that your system has just created a buy signal, and you are wondering whether it would be a wise decision to enter the market.

On the RSI indicator, you can see that there is a value of 77. This tells you that prices have been moving up faster relative to previous trading activity over the last 14 units of whatever time frame your chart is using (if you had a 15 minute chart open then it would be the past 210 minutes), and that the market is considered to be overbought. This is where you can see why this type of indicator is called a "momentum" indicator, because it is revealing to you that the market has recently been rapidly moving upwards.

When your RSI gives you an overbought value, you can judge this one of two ways: either that the market has been moving upwards recently and that it is going to continue to do so, or that the market is "running out of steam" with this upwards movement and that it is likely to reverse. The longer that your RSI tells you that the market has been overbought, the more likely it becomes that this trend is going to reverse. So in this instance, the value of 77 (especially if the RSI only recently moved into overbought territory) would indicate that there is still a lot of room at the top for more upwards movement, and it may be a wise decision to follow this trading signal.

But let's say that when you checked your RSI indicator, it gave you a value or 42. This would probably indicate that the market does not have ver much upwards momentum, so unless you begin to see the RSI rise then it might be a good idea to pass on this buy signal and not enter the market.

In a third possibility, let's say that the RSI gave you a value of 10. Since this is below 30 then the market would be considered to be oversold, but this could still be a good time to enter the market. If the RSI has been in oversold territory for a long time, it may be time for a reversal. If you feel that the market may be running out of steam on it's downward movement and likely to retrace it's movement upward, this may be an excellent time to enter the market.

All in all, you should make your forex trading decisions based on a number of different factors and never make trading decisions based upon only one signal or indicator. While you are sitting at your computer and deciding how best to enter and exit the market, try not to lose perspective of the fact that it is banks, hedge funds, and other individual traders just like you that are moving the market by creating capital flows, and everybody is making trading decisions based on their emotions. So if every indicator in the world is telling you to buy, but you still felt reluctant because you know that there is a prevailing market bias against the currencies involved, it might probably still be a good idea to pass on the trade.