Williams %R
Williams %R is a momentum oscillator developed by Larry Williams that measures the relationship between a security's closing price and the highest high over a specified lookback period, expressed on an inverted scale from 0 to -100. It is closely related in construction to the stochastic oscillator and is a standard tool in the technical analysis literature.
Larry Williams introduced the %R indicator in his 1973 book on commodity trading, and it was subsequently applied broadly to U.S. equity markets. The indicator's calculation computes the difference between the period's highest high and the current close, then divides that by the difference between the highest high and the lowest low over the same period, and multiplies by -100. The resulting value ranges from 0 (when the close equals the highest high of the period) to -100 (when the close equals the lowest low).
The inversion of the scale relative to the stochastic oscillator can be initially counterintuitive. A Williams %R reading near 0 indicates the close is near the top of the recent range, while a reading near -100 indicates the close is near the bottom. Technical analysts in the historical literature have frequently referenced threshold levels around -20 and -80 as descriptors of where the closing price sits within the recent high-low range. As with all technical oscillators, these threshold descriptions are historical observations about price location and are not guarantees of any future price behavior.
Williams %R uses a default lookback period of 14 periods, though practitioners apply varying periods depending on the time frame they are analyzing. The indicator can be applied to any time frame — daily, weekly, or intraday — and is available on virtually every charting platform used by U.S. equity market participants. Its behavior across different market conditions and its relationship to forward returns has been studied in academic finance literature, with results that vary across market regimes and security types.
For educational purposes, it is relevant to understand that Williams %R and the stochastic oscillator will produce nearly identical readings when the same lookback period is used, as both measure the closing price's location within the recent high-low range. The choice between them in practice often comes down to platform availability, familiarity, or the specific scaling convention preferred by the analyst.
Larry Williams is also known for developing the Williams Accumulation/Distribution indicator and for his documented performance in commodity trading championships in the late 1980s, which brought wider attention to his analytical methods. The %R indicator was one of the tools Williams discussed in his educational materials, and it gained traction among U.S. equity technical analysts during the 1980s and 1990s as personal computing made it practical to calculate and display oscillator values automatically on charts. Today it is part of the standard indicator library on virtually every retail and professional charting platform.