What Is the RSI Indicator?

TA analyzes historical market data to forecast future price movements. Widely used across traditional and crypto markets, traders employ tools like RSI for these assessments.

Developed by J. Welles Wilder in 1978, the Relative Strength Index is a momentum oscillator measuring price movement speed and magnitude. Featured in his book New Concepts in Technical Trading Systems, it remains a cornerstone indicator alongside SAR, ATR and ADX.

A former engineer turned trader, Wilder transformed his early trading struggles into groundbreaking TA formulas. His 1978 book - written in just six months - continues to influence traders decades later, proving the enduring value of his technical indicators.

How Is the RSI Calculated?

It’s quite difficult to calculate the RSI. Fortunately, you don’t need to do it manually, as it’s one of the standard indicators implemented in most trading platforms. For instance, you can use TickTrader to examine the RSI without making complicated calculations.

However, it’s worth understanding how the indicator is measured to know which metrics can affect its performance.

The RSI Formula Explained

How to Use RSI Indicator Work?

The Relative Strength Index (RSI) measures the speed and size of price movements on a scale from 0 to 100. Think of it as a speedometer for market momentum. When the RSI is above 70, it signals that prices might be overbought or overvalued. Conversely, when an asset's RSI falls below 30, it indicates that the asset may be oversold or undervalued. Market participants use these signals as warnings, as they often precede price retracements.

It's important to note that prices can still rise in the "overbought" zone or fall in the "oversold" zone. Therefore, combining RSI with other indicators can improve accuracy and success rates.

A common mistake traders make is to buy or sell immediately when the RSI enters an overbought or oversold territory. A better approach is to wait until the RSI crosses back below 70, indicating a potential shift in momentum from buyers to sellers.

Conclusion

While the RSI’s settings, overbought/oversold levels, and divergences are important, traders must acknowledge its inherent limitations and combine it with other tools to improve accuracy and avoid misleading signals.