RSI (Relative Strength Index)

The Relative Strength Index (RSI) is a momentum oscillator that measures the speed and magnitude of recent price changes. It oscillates between 0 and 100, with readings above 70 typically indicating overbought conditions and below 30 indicating oversold conditions. Developed by J. Welles Wilder Jr. in 1978, it remains one of the most widely used technical indicators.

How RSI Is Used in Trading

Traders use RSI primarily to identify overbought and oversold conditions. When RSI rises above 70, the asset may be overextended to the upside, signaling a potential pullback. Conversely, readings below 30 suggest the asset is oversold and may be due for a bounce. These thresholds can be adjusted based on the asset and market conditions.

RSI divergence is another powerful signal. When price makes a new high but RSI fails to confirm with a new high of its own, it suggests weakening momentum and a potential reversal. The same applies in reverse for bearish divergence during downtrends.

Many algorithmic traders combine RSI with other indicators such as MACD or Bollinger Bands for confirmation. The standard period is 14, though shorter periods like 7 or 9 are popular for scalping strategies, and longer periods like 21 or 25 for swing trading.

Access via API

Get RSI values for any symbol and timeframe with a single API call:

Returns the current RSI value, period, and timestamp. Available across all 7 timeframes from M1 to D1.