The stochastic oscillator is a momentum indicator developed by George C. Lane, that measures the level of the close relative to the high-low range over a set period of time, usually 14 periods. This indicator fluctuates between 0 and 100. A currency is overbought (the price is trading near the top of the 14-day range) when the Stochastic is above 80, and oversold (the price is trading near the bottom of the 14-day range) if the indicator is below 20.