Stochastic Oscillator

A momentum indicator that compares a security's closing price to its price range over a given period, oscillating between 0 and 100 to identify overbought and oversold conditions.

The stochastic oscillator, developed by George Lane, is based on the observation that in uptrending markets, closing prices tend to cluster near the highs of the period's range, while in downtrending markets they cluster near the lows. The fast %K line shows where the current close falls within the high-low range over the lookback period (typically 14 periods). The %D line is a moving average of %K and serves as the signal line.

Readings above 80 are considered overbought; below 20 are oversold. Crossovers between %K and %D generate signals: bullish when %K crosses above %D below 20 (buying in oversold territory), bearish when %K crosses below %D above 80 (selling in overbought territory). As with RSI, divergence between price and the stochastic oscillator can signal trend weakening.

The stochastic works best in range-bound markets where overbought and oversold readings are more meaningful. In strong trends it generates numerous premature signals — a stock in a powerful uptrend can register "overbought" for months. Many traders use the stochastic in combination with a trend filter (like a moving average) to take only signals aligned with the dominant trend direction.

This definition is for informational and educational purposes only. Nothing on Finance Compass constitutes financial, investment, or trading advice. Always conduct your own research and consult a qualified professional before making financial decisions.