The relative strength index (RSI) and the stochastic oscillator are price momentum oscillators used to forecast market trends. The two indicators have very different underlying theories and methods despite their similar objectives.

The stochastic oscillator is predicated on the assumption that closing prices should close in the same general direction as the current trend. RSI tracks overbought and oversold levels by measuring the velocity of price movements. More analysts use RSI over the stochastic oscillator but both are well-known and reputable technical indicators.