Home Forex Trading What Is RSI Relative Strength Index Calculation and Formula?

What Is RSI Relative Strength Index Calculation and Formula?


The term ‘Relative Strength Index’ must not be confused with ‘relative strength’ which is when we compare one stock against another or one sector. Moving average convergence/divergence is a momentum indicator that shows the relationship between two moving averages of a security’s price. A related concept focuses on trade signals and techniques that conform to the trend. This scan reveals stocks that are in a downtrend with overbought RSI turning down.

how to calculate rsi

This article will discuss RSI or relative Strength Index, a widely used momentum oscillator for studying buy and sell signals in the price chart. RSI, one of the most popular technical indicators, is computed on the basis of the speed and direction of a stock’s price movement. This library comes with over 100+ technical indicators. It will use the TA-Lib where possible otherwise pandas_ta will make calculations with its own implementations. This method returns a None object unless it is written to a buffer object. This will result in a local file named wilder-rsi-pandas-output.csv saved in our current working directory.

thoughts on “Three ways to calculate the RSI in Python”

Generally, a reading of below 30 shows an oversold situation, and over 70 indicates an overbought condition. Fortunately, you can adjust these levels to fit a certain security. For instance, if a stock reaches an overbought level of 70 several times, then you should adjust it to 80. In fact, it can do more than help you find an oversold or overbought security. It also can indicate securities that are primed for a corrective pullback or trend reversal in price. Even with the current economic news and the latest stock rating report determining when to enter/exit, a position can be quite challenging.

Now that we have all the components ready to calculate the final RSI value, we will simply have to follow our formula from the beginning of the post. Just like the RSI, the SMMA also has a length and time frame. However, these remain the same as the ones chosen for the RSI. So for an n length RSI, we will need to calculate the n length SMMA of the changes. However, in this post, we will have some fun by discussing how to calculate the Relative Strength Index in a step by step guide.

how to calculate rsi

You will find the logic of these calculations is very similar to the calculation of Average True Range , another indicator invented by J. These up and down moves are calculated in columns C and D in the RSI Calculator. The offers that appear in this table are from partnerships from which Investopedia receives compensation. This compensation may impact how and where listings appear. Investopedia does not include all offers available in the marketplace.

Popular in Markets

With this in mind, let us try to see a few strategies based on the RSI indicator. For example, on 26-04, the price had increased by 4.79. Use the body fat calculator to estimate what percentage of your body weight comprises of body fat. When you spot RSI divergence, you have to believe RSI and not the charts. In short, RSI divergence catches the ‘lies on the charts’. The last, fourth trade was able to catch a 65% gain if one had held on till May 2014.

  • The thought of having to make these calculations for any reasonable number of assets seems excruciating.
  • Despite weaker momentum with a lower low in RSI, MMM held above its prior low and showed underlying strength.
  • The average time period we use for the RSI is the 14 period average.
  • The primary trend of the security is important to know to properly understand RSI readings.

The chart you see is of the daily timeframe and uses the technique described above. You will notice that the first trade made a very handsome profit and was able to catch the trend. The second and third did not follow through upwards and would have resulted in a loss. The RSI is used as over bought and over sold indicators, divergences and even centerline crossover. Since the indicator is normalised and bounces between 0 and 100 it can be used to initiate trades using the techniques mentioned above. Please note that these calculations could be done in a much more efficient way.

Usually you want to crosscheck the RSI against other technical indicators. The RSI also known as the relative strength index is a momentum indicator. According to Investopedia it measures https://1investing.in/ the magnitude of recent price changes to evaluate overbought or oversold conditions in the price of a stock or other asset. RSI signals investors regarding the trend of the stock price.

Step 7: Save Output Data

Raising overbought to 80 or lowering oversold to 20 will reduce the number of overbought/oversold readings. Short-term traders sometimes use 2-period RSI to look for overbought readings above 80 and oversold readings below 20. TA-lib uses the same exponential moving average function as our custom function described earlier Walt Disney Stock: A Dividend Analysis in this article. However, the first time it is calculated for a time series, it uses a simple moving average. That’s why it differs slightly at the beginning of our time series. The value of RSI oscillates from 0 to 100, with a value over 70 indicating the oversold condition and below 30 indicating the oversold condition.

The thought of having to make these calculations for any reasonable number of assets seems excruciating. Keep in mind this was long before intraday trading was available and daily price action was the primary focus of technical analysis. Still, it highlights the advantages afforded to modern traders by tools like Python. While we did mention that RSI indicators and MACD indicators have certain similarities, they have a different approach towards it. For example, let’s say that the price has been closing higher than the previous days but the gain is not as substantial as compared to the average gain of the period.

Get the Price Data

The 70 level shows that the underlying asset is overvalued, and soon the market will reverse its trend or make a correction before it continues rising. Conversely, the 30 level indicates undervalued conditions and soon the price of the underlying asset reverses its direction or makes a correction. Take note of the current, the lowest, and the highest RSI readings on the 15th period and calculate the new StochRSI.

Plotting RSI

In particular, Constance Brown’s book, Technical Analysis for the Trading Professional, features the concept of bull market and bear market ranges for RSI. The average gain or loss is the average percentage gains or losses over a look back period of 14 days. Therefore, it’s the best tool for providing short-team investors with sell-and-buy signals. So you should use it together with other technical indicators to support your trading strategies. Like for any other indicators, results of RSI indicator is most reliable when it conforms to long term trends. Actual reversal signs are rare and need to be filtered from false signals.

RSI moved to 30 in March to signal the start of a bear range. The zone subsequently marked resistance until a breakout in December. A 90 day time period, which I call Medium Term Strength. When you look at the relative strength index in comparison to the MACD, VWAP and/or moving averages, you can get a better picture of what’s going on. RSI is a momentum oscillator determining the pace and variation of security prices. You calculate the RSI by taking the average of the most recent gains and dividing it by the average of the most recent losses.

The indicator may also remain in oversold territory for a long time when the stock is in a downtrend. This can be confusing for new analysts, but learning to use the indicator within the context of the prevailing trend will clarify these issues. The RSI provides technical traders with signals about bullish and bearish price momentum, and it is often plotted beneath the graph of an asset’s price.

This is because you understand what the value of the indicator mathematically represents. And when you understand an indicator it means that you can use it in a better way while trading. The Worden Stochastics indicator plots the percentile rank of the latest closing price compared to other closing values in the lookback period. A nine-day EMA of the MACD, called the signal line, is then plotted on top of the MACD line. Traders may buy the security when the MACD crosses above its signal line and sell, or short, the security when the MACD crosses below the signal line. The following chart illustrates the bearish swing rejection signal.


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