In technical analysis, an investor measures oscillators on a percentage scale from 0 to 100, where the closing price is relative to the total price range for a specified number of bars in a given bar chart. In order to achieve this, one deploys various techniques of manipulating and smoothing out multiple moving averages. When the market trades in a specific range, the oscillator follows the price fluctuations and indicates an overbought condition when it exceeds 70 to 80% of the specified total price range, signifying a sell opportunity. An oversold condition exists when the oscillator falls below 30 to 20%, which signifies a buy opportunity.
The signals remain valid as long as the price of the underlying security remains in the established range. However, when a price breakout occurs, the signals may be misleading. Analysts consider a price breakout either the resetting of the range by which the current sideways market is bound or the beginning of a new trend. During the price breakout, the oscillator may remain in the overbought or oversold range for an extended period of time.
Technical analysts consider oscillators better suited for sideways markets and consider them more effective when used in conjunction with a technical indicator that identifies the market as being in a trend or range-bound. For example, a moving average crossover indicator can be used to determine if a market is, or is not, in a trend. Once the analysts determine that the market is not in a trend, the signals of an oscillator become much more useful and effective.