The RSI (Relative Strength Index) is a technical indicator widely used in the financial market to assess the strength or weakness of an asset, such as stocks or cryptocurrencies, based on their recent prices. It was developed by J. Welles Wilder and measures the speed and change of price movements. The RSI ranges from 0 to 100 and is generally used to identify overbought or oversold conditions of an asset.

The RSI formula takes into account the average price changes in periods of highs and lows. The default value for calculation is made with 14 periods (usually days or candles, depending on the chart), but this value can be adjusted according to the trader's strategy. When the RSI is above 70, it indicates that the asset may be overbought, which suggests a possible reversal or price correction. On the other hand, when the RSI is below 30, it indicates an oversold condition, suggesting that the price may be about to recover.

The RSI is useful for identifying market entry and exit points, and while it is not foolproof, it is an effective tool when combined with other indicators and technical analysis.