"WilliamsPercentR" (Financial Indicator)
Is a momentum indicator.
Was developed by Larry Williams.
Is computed using the high, low, and close prices.
Returns one time series, which shows how close the current close is to the highest high relative to the range between the highest high and lowest low over 10 periods.
FinancialIndicator["WilliamsPercentR",n] looks at extreme values over n periods.