Williams %R

What Is Williams %R?

Williams %R, also known as Williams Percent Range, is a momentum oscillator developed by legendary trader Larry Williams in 1973. It measures the level of the close relative to the highest high over a specific lookback period, producing a value between 0 and -100.

The formula is straightforward: %R = (Highest High - Close) / (Highest High - Lowest Low) x -100. When the close is near the top of the range, %R is near 0 (overbought). When the close is near the bottom, %R is near -100 (oversold). This inverted scale can be confusing at first, but it offers a unique perspective compared to traditional oscillators.

The indicator is mathematically very similar to the Stochastic Oscillator, except that Williams %R is plotted on a negative scale and measures the close relative to the high rather than the low. In practice, Williams %R (14) is effectively the inverse of the Fast Stochastic %K (14). Many traders prefer Williams %R because its inverted scale makes it easier to spot overbought conditions at the top of the chart and oversold conditions at the bottom.

How to Use Williams %R

The primary use of Williams %R is identifying overbought and oversold conditions. The two key zones are:

Overbought (0 to -20): When %R enters this zone, the current close is near the top of the recent range. This suggests the rally may be running out of steam and a pullback could follow. However, during strong uptrends, %R can stay overbought for extended periods. A reading in the overbought zone is not an automatic sell signal; it is a warning to watch for weakness.

Oversold (-80 to -100): When %R drops into this zone, the current close is near the bottom of the recent range. This signals that selling pressure may be exhausted and a bounce is possible. In strong downtrends, %R can remain oversold for long stretches, so waiting for %R to exit the zone before acting is often wiser than buying blindly.

The most reliable approach combines Williams %R with a trend filter. In an uptrend (price above the 50-day moving average), focus only on oversold readings as buying opportunities. In a downtrend, focus only on overbought readings as selling opportunities. This alignment with the broader trend dramatically improves the success rate of %R signals.

Divergence signals are among the most powerful setups Williams %R produces. When price makes a new low but %R makes a higher low, selling momentum is fading and a reversal may be imminent. Conversely, when price makes a new high but %R fails to confirm with a new high of its own, buying momentum is weakening.

Common Mistakes

Trading overbought and oversold in isolation. The most frequent error is selling every time %R hits -20 or buying every time it reaches -80. In a strong trend, %R will remain in extreme territory for many bars. Always confirm the signal with a trend direction filter and price action.

Ignoring the trend. Williams %R works best as a mean-reversion tool within a clear trend. Buying oversold readings during a waterfall decline or selling overbought readings during a powerful rally will generate consistent losses. Determine the trend first, then use %R to time entries in the trend's direction.

Using too short a lookback period. Reducing the period below 10 creates a very choppy line that whipsaws constantly. The default 14-period setting provides a good balance between responsiveness and noise reduction. If you need smoother signals, increase the period to 20 rather than lowering it.

Confusing the inverted scale. New traders sometimes misread the chart because -20 is at the top and -80 is at the bottom. Remember: closer to 0 means overbought (price near the high), closer to -100 means oversold (price near the low).

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