General information The Relative Strength Index (RSI) is a momentum oscillator that was introduced by J. Welles Wilder in an article published in Commodities magazine in June 1978. The Relative Strength Index measures the velocity of directional price movement and is commonly used in conjunction with a daily bar chart. However, it can be utilized on a bar chart with any particular time frame. The concept of this oscillator is based upon an idea of an asset being oversold or overbought. Generally, tops and bottoms are indicated when the RSI goes above 70 or drops below 30. Although, failure swings above 70 or below 30 can imply possible market reversal. Similarly, divergence between the RSI and price action on the chart can signal a market turning point. Chart formations and support and resistance often show up graphically on the RSI despite the fact that they may not be apparent on the bar chart. The slope of the momentum oscillator is directly proportional to the velocity of the move. Thus, the distance traveled up or down by the RSI is proportional to the magnitude of the move. The horizontal axis represents time and the vertical axis represents distance traveled by the indicator. The RSI moves slowly when the market continues its directional movement. However, once price is at the market turning point, RSI tends to move faster.
Here is depiction of the weekly chart of USOIL: It is clearly observable that peak in RSI often coincides with peak in the price. Similarly, trough in RSI is often accompanied by trough in the price.
Calculation The Relative Strength Index is commonly calculated using the close price of a 14 day period. The equation for its calculation involves several components.
These are: • Average up closes • Average down closes • Relative strength
Relative Strength (RS) = (average of 14 day's closes up/average of 14 day's closes down) Relative Strength Index (RSI) = 100 – [100: (1 + RS)]
Calculation begins with obtaining the sum of the up closes for the previous 14 days. This sum is then divided by the number of days used in calculating the generating figure for average up closes. Similarly, the sum of the down closes for the previous 14 days is divided by the number of days used in calculating the generating figure for average down closes. After these two operations are conducted, the average up days are divided by the average down days resulting in the value of the Relative Strength (RS). The number 1 is then added to the value of RS. Next, 100 is divided by the new amount of RS. The resulting figure is subsequently subtracted by 100 generating the value of the Relative Strength Index (RSI). From this step on, the previous value of average up closes and average down closes can be used to generate the next value of the RSI. In order to calculate the next average up close, the previous value of average up closes is multiplied by 13 and the present day average up close is added to this figure. This value is then divided by 14 generating the value for the new average up closes. In similar fashion, the new average down close is calculated by multiplying the previous average down closes by 13. Today's down close is then added to the figure. The resulting figure is again divided by 14 to generate the new average down close. After that, the same steps indicated to calculate the initial RSI need to be followed.
Here is depiction of the monthly chart of copper futures market: Similarly like in the previous example positive correlation between peaks and troughs in RSI and price is observable.
Divergence When trend is prevalent and two indexes (or index and price) are going simultaneously either up or down they exhibit positive correlation. However, when this correlation breaks and one index (or price) keeps going up while another index reverses down divergence is said to occur. Technical analyst should pay attention to this instance as it sometimes has abillity to foreshadow upcoming reversal in trend. Though, there are many instances when divergence occurs and reversal in price trend fails to materialize. For this reason some analysts like to implement concept of double divergence.
Here is example of the divergence that we mentioned in our idea on 30th June 2021:
Double divergence There are many instances when price continues its rise and analyst can observe oscillator or idex to fall only to see it later climb back up in tandem with price. (same applies to the opposite situation when price falls and index or oscillator starts to rise) The divergence occured but price trend remained intact. Because the divergence can be misleading, some analysts preffer to wait for the second divergence before placing their entries or exits.
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