Williams %R, or Williams Percent Range, is a type of momentum indicator. It refers to where the current closing price is relative to the high-low range over the past period of time. It is a technical indicator that evaluates both overbought and oversold levels as well as weak and strong boundary.
Williams %R fluctuates between 0 and -100. From 0 to -20 is considered overbought. Reading -20 is overbought line; Between -80 to -100 is oversold area; Readings -80 is oversold line; reading -50 is the midpoint.