Momentum og RSI

RSI er en meget benyttet indikator inden for teknisk analyse. Forkortelsen RSI står for Relative Strength Index og er et mål for, hvor godt en aktie er gået målt op imod sig selv. Tallet beregnes ved at se på styrken i opgangsdagene i forhold til styrken i nedgangsdagene over en bestemt periode, og tildeles en værdi mellem 0 og 100.

En aktie, som er steget meget i forhold til reaktionerne tilbage undervejs, vil have en høj RSI. Tilsvarende vil en aktie, som er faldet meget i forhold til reaktionerne op undervejs, have en lav RSI. RSI bruges både som en indikator for, om en aktie er oversolgt eller overkøbt, og om den har positivt momentum eller negativt momentum.

RSI kan give indikationer som

• Denne aktie er steget meget på kort tid. Optimismen er øgende, og der indikeres en videre opgang.
• Denne aktie er faldet meget på kort tid. Her bliver investorerne stadig mere pessimistiske og vil fortsætte med at gå ned i pris for at kunne komme ud. 

Mange investorer mener, at RSI også kan give indikationer, som at aktier er steget eller faldet for meget og skal reagere tilbage. Investtechs forskning konkluderer, at sådan en overkøbt- oversolgt-tolkning statistisk set ikke stemmer overens med virkeligheden.

Læs forskningsrapporten om RSI her.

RSI som overkøbt/oversolgt-indikator

En aktie bliver overkøbt, når den er steget meget på kort tid uden særlige reaktioner tilbage undervejs. Tanken er, at den da er steget for meget og snart vil reagere tilbage sådan, at man bør sælge.
Tilsvarende bliver en aktie oversolgt, når den er faldet meget på kort tid. Dette kan indikere, at den snart vil få en reaktion op og bør købes. Se eksempel herunder.

RSI som momentumindikator

RSI bruges imidlertid også som en momentumindikator. Tanken her er, at store kursbevægelser indikerer, at investormassen er i bevægelse. Da gælder det om at hænge på og være med på bevægelserne, som er startet, med tanke på at endda flere investorer kommer med senere og driver kurserne videre i samme retning. Se eksempel herunder.

High positive momentum and overbought

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:

• Indicates short term strength
• Indicates that investors are positive and that the price will continue to rise
• Many investors think this is a negative signal, but our research shows it is clearly positive

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.

Investtech Research: High positive momentum and overbought

+7.4pp

Stocks with these ostosignaalit 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)
Ostosignaalit keskipitkä tähtäin	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.

Lue lisää

• Research Report: RSI - Relative Strength Index – signal statistics for the Nordic markets, 1996 to 2018 (Vaadittu käyttäjätaso PRO)
• Research Article: RSI is a good momentum indicator
• Research Article: Buy signals: Strong positive momentum: Research results 2021-2023
• Research Report: Investtech-forskning: RSI - Relative Strength Index - signalstatistikk nordiske markeder 2019 og 2020 (Vaadittu käyttäjätaso PRO)
• Research Article: Investtech-forskning: Høy RSI var et godt kjøpssignal under koronapandemien

High negative momentum and oversold

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:

• Indicates short term weakness
• Indicates negative investors and that prices will continue to fall
• Many investors think it is a positive signal, but our research shows it is clearly negative

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.

Investtech Research: High negative momentum and oversold

-5.7pp

Stocks with these myyntisignaalit 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)
Myyntisignaalit keskipitkä tähtäin	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.

Lue lisää

• Research Report: RSI - Relative Strength Index – signal statistics for the Nordic markets, 1996 to 2018 (Vaadittu käyttäjätaso PRO)
• Research Article: RSI is a good momentum indicator
• Research Article: Sell signals: Strong negative momentum. Research results 2021-2023
• Research Report: Investtech-forskning: RSI - Relative Strength Index - signalstatistikk nordiske markeder 2019 og 2020 (Vaadittu käyttäjätaso PRO)
• Research Article: Investtech-forskning: Høy RSI var et godt kjøpssignal under koronapandemien