In previous articles on the three forex technical studies that we are exploring in this article series, we have established that MACD, RSI, Bollinger Bands and Stochastic Oscillator are four commonly used technical indicators across the world and that their use on daily timeframe can help to confirm intraday signals. This article continues the series by discussing the Relative Strength Index, put together originally in the 70's by one J Welles Rider.

J Welles Riders Relative Strength Index is an oscillator that gives indication of momentum of a security. The greatness of recent gains are compared with the size of recent losses. It must be noted that this is a different concept to relative strength which measures an individual stock or funds performance related to to a benchmark index such as the NASDAQ or DJIA. Let's now explore the Relative Strength Index as it may be used in the forex market.

The scale used on the RSI indicator is that of zero to one hundred usually with two levels marked at seventy and thirty which determine when the market is oversold and when it is overbought. Whilst the default setting of this indicator is 14, some traders may use 21 periods. Whereas the Stochastic Oscillator indicator is typically set at 80% and 20% to determine overbought and oversold levels in the market, as stated, the RSI tends to differ in it's parameters and use 30% and 70% for these levels. A 50% line is also plotted on the RSI to ascertain whether gains for the period outweigh losses for the period and vice versa.

When the market is not in a strong uptrend or downtrend, price action may confine itself to moving between two horizontal channels. These channels or bands can also exist within an overall trend and indeed, within each other. However, taking a non-trending market as an example (also known as a channeling market), is a useful time to employ the use of oscillators confined to a percentage scale, including the RSI. This is because when the market is trending, it may continue to hold in an overbought or oversold position and move in that direction causes an extended time period in which the RSI remains above/below the 70 or 30 levels respectively.

When the market is channeling (ie there is not a clear strong uptrend or downtrend) the RSI can be an extremely useful tool because turning points in the market can be gauged from the overbought and oversold areas and the action of the RSI line. For example a cross from above the 70 line to below the 70 line can be interpreted as a directional change from overbought in to selling or correctional action and a cross to above 30 from below thirty can signal near-term bullishness after an oversold market.

In summary, the RSI line is mapped on a scale between 0-100. The 50 line is important because it gives an idea as to gains outweighing losses or vice versa over the timeframe period the indicator is set to. In channeling markets, the overbought and oversold levels can give an indication of directional change, and this can be confirmed by a close below the 70 from being above 70 (bearish reversal) or a close above 30 from the RSI being below the 30 level (bullish reversal).