Stochastic Oscillator
Type: Momentum Oscillator
The Stochastic Oscillator compares a closing price to its price range over a given period, generating a momentum reading that oscillates between 0 and 100. It's particularly effective in ranging markets for identifying short-term reversals.
How it Works
Developed by George Lane, the Stochastic measures where the closing price sits relative to the high-low range over a set number of periods (default: 14). A reading near 100 means price closed near the top of its range; near 0 means it closed near the bottom.
The indicator has two lines: %K (the fast line, raw calculation) and %D (the slow line, a 3-period moving average of %K). Most traders use the 'slow' stochastic, which smooths out noise.
How to Read It
Readings above 80 are considered overbought; readings below 20 are oversold. The %K and %D lines crossing each other generate entry signals, similar to MACD crossovers.
Stochastic is most effective in ranging markets. In strong trends it will stay in overbought/oversold territory for long periods, just like RSI.
Key Signals
• Bullish crossover (<20): %K crosses above %D in the oversold zone — potential buy signal.
• Bearish crossover (>80): %K crosses below %D in the overbought zone — potential sell signal.
• Divergence: Price makes a new low but Stochastic makes a higher low — bullish divergence, possible reversal incoming.
• Centreline: Stochastic crossing 50 can confirm direction in a trending environment.
Limitations
• Highly prone to false signals in trending markets — overbought can stay overbought for the entire trend.
• The default 14-period setting may need adjustment for different timeframes and instruments.
• Crossovers inside the overbought/oversold zones are more significant than those in the middle range.
Trader's Tip: Stochastic works best on ranging charts. Before using it, check whether the market is trending or ranging. If it's trending strongly, rely on MACD or moving averages instead — Stochastic will just give you whipsaw signals.