A momentum oscillator developed by Larry Williams that measures a security's closing price relative to the highest high over a specified lookback period, typically 14 periods. The indicator ranges from 0 to -100, with readings above -20 considered overbought and readings below -80 considered oversold. Williams %R is mathematically similar to the stochastic oscillator but uses an inverted scale, making interpretation slightly different.
Example
“Williams %R dropped below -80 for the third time in two weeks, and the subsequent bullish divergence with price making a higher low signalled a potential reversal.”