Levy’s Relative Strength Indicator (RSL) is used to identify the instruments showing strength and weakness. The concept of Relative Strength to Levy is based on the assumption that securities which exhibited a large relative strength in the past will also develop relatively strongly in the future, and conversely. RSL is used to create balanced long-short portfolios in trading portfolios. For Currency traders, RSL can be used to pick the currency pairs showing the highest strength and weakness. Traders create a portfolio of positions by buying stronger instruments and selling the weaker instruments.
The first step in creating a long-short portfolio is ranking all instruments based on their strength and weakness. Note down the RSL value of each currency pair at the start of the week or month. The pair that has the highest RSL value is the strongest one. The pair that has the lowest RSL value is the weakest one. Now open Buy positions on the top two stronger pairs and open sell positions on top two weaker pairs. Keep the positions open for the next week or month start. At the start of next week or month, again rank the instruments based on their RSL values and adjust the positions. This portfolio is hedged, market neutral and offer steady return over long periods of time.