Guide to Using the Stochastic Oscillator Indicator

The Stochastic Oscillator is a valuable indicator for assessing momentum or trend strength. It, along with other oscillators, is relatively easy to understand with clear buy and sell signals. However, relying too heavily on these signals without deeper understanding can lead to disappointing results. To avoid such pitfalls, new traders must have a solid grasp of the Stochastic Oscillator.

What is the Stochastic Oscillator?

The Stochastic Oscillator is a momentum indicator that evaluates whether a security is overbought or oversold compared to its price range over a specific period. Essentially, it measures the price level as a percentage of the range (high price – low price) over a determined period.

Guide to Using the Stochastic Oscillator Indicator


How Does the Stochastic Oscillator Work?

The Stochastic Oscillator consists of two lines oscillating between two horizontal lines. The solid black line in the image below is called %K, calculated using a specific formula (explained later), while the red dashed line is the 3-period moving average of the %K line.

Prices are considered ‘overbought’ when both lines break above the upper horizontal line (typically the 80 threshold) and ‘oversold’ when they break below the lower horizontal line (typically the 20 threshold).

Timing Entries

The Stochastic Oscillator provides insights when determining entry points. When both lines are above the ‘overbought’ level (80) and the %K line crosses below the dotted %D line, this is considered a signal to enter a short position. Conversely, when the %K line crosses above the %D line while both lines are below the ‘oversold’ level (20), it is a signal to enter a long position.

Traders should not blindly trade based solely on overbought/oversold levels. It is crucial to understand the overall trend and filter trades accordingly.

Guide to Using the Stochastic Oscillator Indicator


When looking at the USD/SGD chart below, since the overall trend is downwards, traders should only look for short entry signals at the overbought levels. Only when the trend reverses or a trading range is established should traders look for long entry points in oversold conditions.

Guide to Using the Stochastic Oscillator Indicator

Stochastic Oscillator Formula

The following formula is calculated for a 14-period stochastic oscillator. The period can be adjusted to suit the desired timeframe.

Calculating %K:



  • C = Most recent closing price
  • L14 = Lowest price over the past 14 periods
  • H14 = Highest price over the past 14 periods

Calculating %D:

%D=Simple Moving Average of %K

The most common %D calculation is a 3-period moving average.

Advantages and Disadvantages of the Stochastic Oscillator

Traders need to understand the pros and cons of the Stochastic Oscillator to maximize its utility.


  • Easy to Understand: The indicator is straightforward to grasp and use.
  • Clear Entry/Exit Signals: Provides clear buy/sell signals.
  • Frequent Signals: Depending on the chosen time settings, it can generate frequent signals.
  • Widely Available: It is available on most technical analysis tools.


  • False Signals: The Stochastic Oscillator can generate false signals if used incorrectly.


The Stochastic Oscillator is an excellent tool for identifying overbought and oversold conditions over a specific period. It is favored by many traders when prices are oscillating within a range, resulting in reliable signals. However, traders should avoid blindly shorting at overbought levels in an uptrend or going long in a downtrend.


  1. Identifying Entry Points:
    • When the %K line crosses below the %D line in the overbought region (above 80), it signals a potential short entry.
    • Conversely, when the %K line crosses above the %D line in the oversold region (below 20), it signals a potential long entry.
  2. Trend Filtering:
    • In a downtrending market, like the USD/SGD example, focus on short signals at overbought levels to align with the trend.
    • In an uptrending market, look for long signals at oversold levels to ensure trades are in the direction of the overall trend.

By integrating the Stochastic Oscillator with an understanding of the broader market trend and proper risk management, traders can enhance their decision-making process and avoid common pitfalls.