RSI is an often used indicator in technical analysis. RSI means Relative Strength Index, and it measures how well a stock has performed compared to itself. The figure is calculated by looking at the strength of days with rising prices compared to strength of days with falling prices over a certain period of time and it gets a value between 0 and 100.
A stock that has risen a lot compared to reactions back during this time, will have high RSI. Similarly a stock that has fallen a lot compared to reactions back, will have low RSI. RSI is used as an indicator of whether a stock is oversold or overbought, and if it has positive momentum or negative momentum.
RSI can indicate that:
Many investors also think that RSI indicates whether a stock has risen or fallen too much and will react back. Investtech’s research shows that this overbought and oversold interpretation is statistically not true.
Read the research report on RSI here.
A stock is overbought when it has risen a lot in a short time, without any significant reactions back during the time period. The idea is that it has risen too much and will have a reaction back soon, indicating that it is time to sell the stock. Similarly a stock is oversold when it has fallen a lot in a short time. This may indicate that it will have a reaction up soon and should be bought before then. See example below.
RSI is also used as a momentum indicator. The idea is that major price movements indicate that the investors as a group are in motion. It is thought necessary to join the early movements, as even more investors will join later and drive the price further in the same direction. See example below.
RSI above 70 shows strong positive momentum in the stock. The stock has risen in the short term, with few reactions downwards. Investors have continued to pay more to buy stocks. This indicates that more buyers are entering the stock and that the price will continue to rise.
RSI above 70 used to be considered a sign of danger. These stocks were said to be overbought and it was assumed they would soon see a reaction down. However, Investtech’s research shows that these stocks have continued to rise, in fact more so than the market.
The following applies to high RSI:
In general we want high RSI, i.e. strong short term momentum, for stocks we own or are going to buy. It can be a psychological challenge to buy such stocks, since they have already risen quite a bit and may seem expensive. However, high RSI indicates that more investors are buying and that the rise will continue.
Stocks with these positive signals have on average outperformed the market in the following months. Annualised excess return has been 7.4 percentage points (pp). This is significantly better than benchmark.
Annualised return (based on 66-day figures) | |
Positive signals medium term | 17.1% |
Reference index | 9.7% |
Excess return | 7.4pp |
The research results are based on 35864 signals from Nordic stocks in the period 2008-2020.
RSI below 30 shows strong negative momentum in the stock. The stock has fallen a lot in a short time, without significant reactions upwards. Investors keep reducing the price to sell their stocks. This indicates that investors are leaving the stock, pessimism is increasing and the price will continue to fall.
RSI below 30 used to be considered a good buy opportunity. These stocks were oversold, having fallen a lot in a short time. The theory said they would soon see a reaction upwards. However, Investtech’s research shows that these stocks have clearly underperformed compared to the market.
The following applies to low RSI:
Stocks with low RSI have negative momentum and our research shows you should stay away from such stocks. It may be tempting to buy such stocks, because they have fallen a lot and seem cheap. However, low RSI indicates increasing pessimism and that the price will continue to fall.
Stocks with these negative signal have on average underperformed compared to benchmark in the following months. Annualised negative excess return has been 5.7 percentage points (pp). This is significantly weaker than benchmark.
Annualised return (based on 66-day figures) | |
Negative signal medium term | 6.1% |
Reference index | 11.7% |
Excess return | -5.7pp |
The research results are based on 24920 signals from Nordic stocks in the period 2008-2020.
Investtech guarantees neither the entirety nor accuracy of the analyses. Any consequent exposure related to the advice / signals which emerge in the analyses is completely and entirely at the investors own expense and risk. Investtech is not responsible for any loss, either directly or indirectly, which arises as a result of the use of Investtechs analyses. Details of any arising conflicts of interest will always appear in the investment recommendations. Further information about Investtechs analyses can be found here disclaimer.
The content provided by Investtech.com is NOT SEC or FSA regulated and is therefore not intended for US or UK consumers.
Investtech guarantees neither the entirety nor accuracy of the analyses. Any consequent exposure related to the advice / signals which emerge in the analyses is completely and entirely at the investors own expense and risk. Investtech is not responsible for any loss, either directly or indirectly, which arises as a result of the use of Investtechs analyses. Details of any arising conflicts of interest will always appear in the investment recommendations. Further information about Investtechs analyses can be found here disclaimer.
The content provided by Investtech.com is NOT SEC or FSA regulated and is therefore not intended for US or UK consumers.