Relative Strength Index
One of the most popular technical analysis indicators, the Relative Strength Index (RSI) is an oscillator that measures current price strength in relation to previous prices. The RSI is a versatile tool, it can be used to:
- Generate buy and sell signals
- Show overbought and oversold conditions
- Confirm price movement
- Warn of potential price reversals through divergences
The chart below shows how the RSI can generate easy to follow buy and sell signals:
RSI Buy Signal
Buy when the RSI crosses above the oversold line (30).
RSI Sell Signal
Sell when the RSI crosses below the overbought line (70).
Varying the time period of the Relative Strength Index can increase or decrease the number of buy and sell signals. In the chart below of Gold, two RSI time periods are shown, 14-day (default) and 5-day. Notice how decreasing the time period made the RSI more volatile, increasing the number of buy and sell signals substantially.
There is another way the Relative Strength Index gives buy and sell signals. Given Below-
RSI Divergences
An alternative way that the Relative Strength Index (RSI) gives buy and sell signals is given below:
- Buy when price and the Relative Strength Index are both rising and the RSI crosses above the 50 Line.
- Sell when the price and the RSI are both falling and the RSI crosses below the 50 Line.
An example of this methodology for buying and selling based on 50 Line crosses is given below in the chart-
For another interesting and under-utilized method for using the RSI indicator for buy and sell signals, see: Stochastic RSI, which combines both the popular Stochastics indicator and the Relative Strength Index.
Relative Strength Index Confirmations & Divergences
A powerful method for using the Relative Strength Index is to confirm price moves and forewarn of potential price reversals through RSI Divergences.
The chart below contract shows the RSI confirming price action and warning of future price reversals:
Low #1 to Low #2
The E-mini Nasdaq 100 Futures contract's price made a substantial move from Low #1 to Low #2. The RSI confirmed this move, helping a trader have confidence jumping on board the price move higher. The break of trendline of the e-mini future was also confirmed by the trendline break of the Relative Strength Index, confirming that the price move was likely over.
Low #3 to Low #4
A bullish divergence was registered between Low #3 and Low #4. The e-mini Nasdaq 100 future made lower lows, but the RSI failed to confirm this price move, only making equal lows. An astute trader would see this RSI divergence and begin taking profits from their shortsells.
High #1 to High #2
A bearish divergence occured when the e-mini futures contract made a higher high and the RSI made a lower high. This bearish divergence warned that prices could be reversing trend shortly. A trader should consider reducing their long position, or even completely selling out of their long position. The Relative Strength Index is a popular tool for generating buy and sell signals, confirming trends, and warning of impending price reversals.