A stochastic oscillator is a momentum indicator comparing a particular closing price of a security to a range of its prices over a certain period of time. The sensitivity of the oscillator to market movements is reducible by adjusting that time period or by taking a moving average of the result. It is used to generate overbought and oversold trading signals, utilizing a 0-100 bounded range of values.
Understanding the Stochastic Oscillator
Traditionally, readings over 80 are considered in the overbought range, and readings under 20 are considered oversold. However, these are not always indicative of impending reversal; very strong trends can maintain overbought or oversold conditions for an extended period. Instead, traders should look to changes in the stochastic oscillator for clues about future trend shifts.
Stochastic oscillator charting generally consists of two lines: one reflecting the actual value of the oscillator for each session, and one reflecting its three-day simple moving average. Because price is thought to follow momentum, the intersection of these two lines is considered to be a signal that a reversal may be in the works, as it indicates a large shift in momentum from day to day.
Divergence between the stochastic oscillator and trending price action is also seen as an important reversal signal. For example, when a bearish trend reaches a new lower low, but the oscillator prints a higher low, it may be an indicator that bears are exhausting their momentum and a bullish reversal is brewing.
Limitations of the Stochastic Oscillator
The primary limitation of the stochastic oscillator is that it has been known to produce false signals. This is when a trading signal is generated by the indicator, yet the price does not actually follow through, which can end up as a losing trade. During volatile market conditions, this can happen quite regularly. One way to help with this is to take the price trend as a filter, where signals are only taken if they are in the same direction as the trend.
Source: Investopedia, Stochastic Oscillator: What It Is, How It Works, How To Calculate, accessed 27 December 2023, <https://www.investopedia.com/terms/s/stochasticoscillator.asp>