RSI (relative strength index)

The relative strength index (RSI) is a momentum indicator developed by technical analyst J. Welles Wilder and introduced in 1978. It compares the size of recent gains with recent losses and expresses the result on a scale from 0 to 100, usually over 14 periods.

Traditionally, an RSI above 70 suggests an asset is "overbought" and may be due for a pullback, while an RSI below 30 suggests it is "oversold". In strong crypto trends, however, RSI can stay above 70 or below 30 for weeks, so these readings alone are not sell or buy signals.

Traders often look for divergence: if price makes a new high but RSI makes a lower high, upward momentum may be weakening. RSI is one of the default indicators on TradingView and most exchange charts. Like all indicators, it is derived from past prices and works best combined with other tools and sound risk management.