RSI Indicator – Part I


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The Relative Strength Index (RSI) indicator, as the name suggests, tells us the relative strength of the asset. RSI is counted as a robust technical indicator.

RSI calculation with the help of an example

Let’s understand how to calculate and graph the RSI indicator. While you can easily calculate the RSI indicator value with the Python code, for explanation purposes we will do it manually.


Step 1: Closing Price

We will take the closing price of the stock for 30 days. The closing price is mentioned in column (1).

Step 2: Changes in Closing Price

We then compare the closing price of the current day with the previous day’s closing price and note them down. Thus, from the table, for 25-04, we get the change in price as (280.69 – 283.46) = -2.77.

Similarly, for 26-04, Change in price = (Current closing price – Previous closing price) = (285.48 – 280.6) = 4.79. We will then tabulate the results in the column mentioned as “Change (2)”. In this manner, we calculated the change in price.

Step 3: Gain and Loss

We will now create two sections depending on whether the price increased or decreased, with respect to the previous day’s closing price.

If the price has increased, we note down the difference in the “Gain” column, and if it’s a loss, then we note it down in the “Loss” column.

For example, on 26-04, the price had increased by 4.79. Thus, this value would be noted in the “Gain” column.

If you look at the data for 25-04, there was a decrease in the price by 2.77. Now, while the value is written as negative in the “change” column, we do not mention the negative sign in the “Loss” column. And only write it as 2.77. In this manner, the table for the columns “Gain (3)” and “Loss (4)” is updated.

In the next article, Rekhit will discuss Average Gain and Loss

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