What Is RSI? Explaining the Relative Strength Index - SmartAsset (2024)

What Is RSI? Explaining the Relative Strength Index - SmartAsset (1)

Unlike investing, trading requires a very active approach within the investment market. Rather than buying and holding assets to build wealth over the course of many years, a trader frequently buys and sells stocks, commoditiesand other securities to achieve higher returns. To guide their investment decisions, traders use a variety of analysis tools, like averages, oscillators and indicators. These principles help them understand how an asset or market is performing so that an educated investment can be made. One such tool is the Relative Strength Index, otherwise known as RSI.

Do you have questions about RSI or other investing principles? Speak with a local financial advisor today.

What Is the Relative Strength Index (RSI)?

So, what is RSI? The Relative Strength Index is a technical momentum indicator. It measures the speed and magnitude of an asset’s recent price changes. This helps traders identify assets that are potentially overbought – meaning they are trading above their true value – or oversold, meaning they are trading below their true value.

RSI comes from analyst James Welles Wilder Jr. He introduced the concept in his 1978 book, “New Concepts in Technical Trading Systems.” Welles Wilder Jr. called it the Relative Strength Index because it compares the strength of an asset on its up days to the strength of the same asset on its down days. Welles Wilder Jr. suggested collecting data from the past 14 trading periods, or days. RSI remains one of the most popular tools among traders.

How to Calculate and Understand RSI

RSI oscillates on a scale of zero to 100. It is usually depicted graphically.

The formula to calculate RSI is:

  • RSI = 100 – [100 ÷ ( 1 + (Average Gain During Up Periods ÷ Average Loss During Down Periods ))]

To calculate RSI even more precisely, you can use previous averages when determining current average gain or loss:

  • Average Gain = [(Past Average Gain) x 13 + Current Gain] ÷ 14
  • Average Loss = [(Past Average Loss) x 13 + Current Loss] ÷ 14

RSI values above 70 indicates that an asset is becoming overbought and the market is bullish, while an RSI reading below 30 indicates that an asset is becoming oversold and the market is bearish. An RSI of 50 represents neutral conditions.

What Are the Benefits of Using RSI?

As stated above, RSI charts can help you predict how an asset or market will perform. In general, if you see an overbought, or overvalued, condition, you can expect that there will be a corrective decline in price soon. Oversold, or undervalued, conditions signal that a price increase could be coming. In other words, you should buy a stock when it reaches an RSI of 30 and sell or short when it hits an RSI of 70.

Some traders use more extreme RSI values of 20 for buying and 80 for selling to play it “safe” with more volatile assets. If you want to confirm the trend reversal is happening, wait a little longer. Only buy once the RSI crosses below 30 then starts to rise again. Sell or short when RSI passes 70 then falls back below.

Of course, it can’t be that simple. Markets aren’t that predictable, and each asset moves differently. Some remain oversold or overbought for a long time. While RSI is a powerful tool, it is much more reliable in a ranging market. In fact, it can send misleading signals in a trending market. No matter what the market conditions, you should always combine RSI readings with other indicators to validate reversal predictions. While it’s possible to do so yourself, a financial advisor can help you consider a wide range of market data in making investment decisions.

RSI also help traders identify divergences, which is when the RSI reading does not match an asset’s movement. Bullish, or positive, divergence occurs when an asset reaches a new low in price, and the RSI value does not. Most traders take this as a signal to buy because selling momentum is slowing and the price will likely climb.

Bearish, or negative, divergence, on the other hand, occurs when an asset reaches a new high in price, but the RSI value does not.This is commonly interpreted as a sell signal because buying momentum is slowing and the price will likely drop. Divergences can confirm other signals and indicate when a trend may be ending.

Last but certainly not least, RSI helps traders determine and confirm general trends. By trading in the direction of the trend, you can make more money. RSI can show patterns the underlying price chart cannot, like double tops and bottoms as well as support and resistance, that predict price changes further ahead.

Bottom Line

What Is RSI? Explaining the Relative Strength Index - SmartAsset (3)

The Relative Strength Index (RSI) is a powerful trading tool with many uses. It has remained relevant for more than 30 years despite market changes and the development of more sophisticated trading technology and tools.

You can use RSI to predict market behavior and asset values, but it should only be one indicator in any comprehensive trading strategy. It’s also important not to confuse RSI with relative strength, which compares the performance of different assets.

Investing Tips

  • A financial advisor can help you create a financial plan for your investing needs and goals.SmartAsset’s free toolmatches you with up to three vetted financial advisors who serve your area, and you can interview your advisor matches at no cost to decide which one is right for you. If you’re ready to find an advisor who can help you achieve your financial goals, get started now.
  • Financial advisors often require minimum investment amounts. If you’re just starting out, you might not be able to meet these minimums. A good alternative for new investors is a robo-advisor, an automated service that chooses investments based on your goals and keeps your portfolio properly balanced.

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What Is RSI? Explaining the Relative Strength Index - SmartAsset (2024)

FAQs

What Is RSI? Explaining the Relative Strength Index - SmartAsset? ›

It measures the speed and magnitude of an asset's recent price changes. This helps traders identify assets that are potentially overbought – meaning they are trading above their true value – or oversold, meaning they are trading below their true value. RSI comes from analyst James Welles Wilder Jr.

How do you explain relative strength index? ›

RSI measures the speed and magnitude of a security's recent price changes to evaluate overvalued or undervalued conditions in the price of that security. The RSI can do more than point to overbought and oversold securities.

What is the interpretation of RSI? ›

Description. The Relative Strength Index (RSI), developed by J. Welles Wilder, is a momentum oscillator that measures the speed and change of price movements. The RSI oscillates between zero and 100. Traditionally the RSI is considered overbought when above 70 and oversold when below 30.

Is relative strength and RSI the same? ›

The difference between relative strength and RSI is essentially a difference of perspective. The relative strength tells about the value of a stock in comparison to another stock, index or benchmark, while the RSI tells about the performance of a stock in comparison to the recent performance of the same stock.

What does RSI mean strength? ›

The reactive strength index (RSI) describes the individual's capability to quickly change from an eccentric muscular contraction to a concentric one [1]. In other words, the RSI was created to assess the athlete's reactive strength, and it was originally measured with the drop jump (DJ) test [1].

What is RSI for dummies? ›

Relative Strength Index (RSI): The Relative Strength Index is the average of the number of upward price movements in a period divided by the average of the number of downward price movements. The higher the RSI, the more interested people are in buying rather than selling.

What is the logic behind the relative strength index? ›

It is intended to chart the current and historical strength or weakness of a stock or market based on the closing prices of a recent trading period. The indicator should not be confused with relative strength. The RSI is classified as a momentum oscillator, measuring the velocity and magnitude of price movements.

How to read the RSI indicator? ›

Low RSI levels, below 30, generate buy signals and indicate an oversold or undervalued condition. High RSI levels, above 70, generate sell signals and suggest that a security is overbought or overvalued.

What is a good RSI index? ›

The relative strength index (RSI) provides short-term buy and sell signals. Low RSI levels (below 30) generate buy signals. High RSI levels (above 70) generate sell signals. The S&P 500's RSI suggests stocks may be expensive.

How reliable is the relative strength index? ›

It is important to understand that RSI signals are not 100% accurate and do not always work. Since the indicator displays momentum, it can stay overbought or oversold for a long time when an instrument has significant momentum in either direction.

What is the formula for RSI relative strength index? ›

RSI = 100 - (100/1 + RS)

To calculate the second RSI for the stock to build a graph, you will need an extra closing price for the stock, which would give you a new average. Once you have got new averages, recalculate the Relative Strength and get a second RSI value using the same formula.

How is relative strength defined? ›

Relative strength is a calculation of the price trend of a stock or a financial instrument in comparison to another instrument, stock, or industry. It shall be determined by taking the price of one commodity and dividing it by another.

What is the most accurate RSI setting? ›

As mentioned before, the normal default settings for RSI is 14 on technical charts. But experts believe that the best timeframe for RSI actually lies between 2 to 6. Intermediate and expert day traders prefer the latter timeframe as they can decrease or increase the values according to their position.

How powerful is RSI indicator? ›

In conclusion, the Relative Strength Index (RSI) is a powerful tool in the trader's arsenal, offering a window into the market's soul. It provides traders with a numerical narrative of overbought and oversold conditions, potential trend reversals, and the strength of market movements.

Why RSI 70 and 30? ›

At the heart of the 70/30 RSI strategy lies the establishment of two key threshold levels on the RSI indicator: 70 for overbought conditions and 30 for oversold conditions. These thresholds serve as crucial markers for generating buy or sell signals, offering traders valuable guidance in navigating market trends.

What makes RSI worse? ›

Cold temperatures and vibrating equipment are also thought to increase the risk of getting RSI and can make the symptoms worse. Stress can also be a contributing cause.

What does relative strength ranking mean? ›

Relative Strength Comparison compares a security's price change with that of a "base" security or index. When the Relative Strength Comparison indicator is moving up, it shows that the security's price is performing better than the base security/index in relative terms.

What is a good RSI to buy? ›

The relative strength index (RSI) provides short-term buy and sell signals. Low RSI levels (below 30) generate buy signals. High RSI levels (above 70) generate sell signals.

How to use the RSI indicator effectively? ›

The common levels to pay attention to when trading with the RSI are 70 and 30. An RSI of over 70 is considered overbought. When it is below 30 it is considered oversold. Trading based on RSI indicators is often the starting point when considering a trade, and many traders place alerts at the 70 and 30 marks.

What is the meaning of relative strength number? ›

Relative strength is a calculation of the price trend of a stock or a financial instrument in comparison to another instrument, stock, or industry. It shall be determined by taking the price of one commodity and dividing it by another.

References

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