The oscillator is a technical analysis oscillator developed by Larry Williams based on a notion of buying or selling "pressure" represented by where a day's closing price falls within the day's true range. An oscillator that attempts to combine information for several different time periods into one number. Three different time periods are used: 7, 14 & 28 days.
Williams had specific criteria for a buy or sell signal. A buy signal occurs when:
Larry Williams developed the ultimate oscillator as a way to account for the problems experienced in most oscillators when used over different lengths of time.