The stochastic oscillator is a momentum indicator that compares a security's closing price to the range of prices over a set number of periods. Readings move between 0 and 100, with values near 0 indicating the close is near the period's low and values near 100 indicating the close is near the high. The tool typically uses two lines, %K and %D, to show current momentum and its smoothed version.
Two lines are plotted: %K, the fast line, and %D, a moving average of %K. A common setup uses 14 periods for %K and a 3 period simple moving average for %D, though variations exist. Readings above 80 are discussed as overbought and readings below 20 as oversold, but these thresholds do not guarantee price direction and can persist in strong trends. Crossovers where %K moves above %D (or vice versa) have historically been watched as momentum cues, especially when they occur near important price levels. Divergences between the oscillator and price action, such as the price making a new high while the oscillator does not, can suggest momentum weakness.
There are fast, slow, and full stochastic variants that adjust smoothing. In trending markets, the oscillator can remain in extreme zones for extended periods, reducing reliability for timing turns. For best results, use stochastic readings in the context of price action and with other indicators or analysis methods.
A trader notes that the %K line crosses above the %D line from below the 20 level, indicating momentum has shifted upward while price action remains near current levels.
RSI (Relative Strength Index) · MACD (Moving Average Convergence Divergence) · Divergence · Overbought and oversold conditions · Price action