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Key Takeaways
- The Ultimate Oscillator, developed by Larry Williams and published in Technical Analysis of Stocks and Commodities in 1985, folds buying pressure measured over 7, 14, and 28 periods into one bounded 0 to 100 line.
- Buying pressure is the close minus the true low, and the denominator is true range, the true high minus the true low, where both the true low and the true high take the prior close into account.
- Each window contributes a sum of buying pressure divided by a sum of true range, so the three components are ratios of sums rather than averages of per-bar ratios.
- The component weights are 4/7, 2/7 and 1/7. The overlapping windows place the largest combined weight on the most recent bars.
- Williams designed the three-window blend to suppress the false bearish divergences that single-period oscillators print early in a strong advance.
- The rule set Williams published is asymmetric and requires a divergence plus a break of the oscillator trend: the long setup is gated below 30, the short setup above 50, while 70, 65, and 45 are exit and stop levels rather than entry gates.
What is the Ultimate Oscillator?
The Ultimate Oscillator is a momentum indicator developed by Larry Williams that combines buying pressure over 7, 14 and 28 bars into one reading on a 0-to-100 scale. Each window divides summed buying pressure, the close minus the true low, by summed true range, and the three components carry weights of 4/7, 2/7 and 1/7.
Its input called buying pressure is a distance between prices, not signed trading volume. Read it as the indicator’s defined range-position measure.
How is the Ultimate Oscillator calculated?
True low is the lower of the current low and the preceding close. True high is the higher of the current high and preceding close.
Buying pressure = close − true low. True range = true high − true low.
Sum each quantity separately over the selected window, then divide summed buying pressure by summed true range. Each denominator must be positive. Repeat for 7, 14 and 28 bars, and calculate UO = 100 × (4 × component 7 + 2 × component 14 + component 28) / 7.
A complete 28-bar calculation needs those 28 high/low/close observations plus the preceding close.
Formula
BP = Close − True Low; TR = True High − True Low; Avg(n) = sum(BP over n bars) / sum(TR over n bars); UO = 100 × [4 × Avg(7) + 2 × Avg(14) + Avg(28)] / 7- True Low is the lower of the current low and the prior close; True High is the higher of the current high and the prior close.
- Buying pressure is the conventional name for close minus true low. It is a price-distance input, not signed trading volume.
- TR is the same true range Wilder defined for Average True Range, expressed through the true high and true low.
- Avg(n) sums BP and TR separately across n bars and then divides the sums; it is not the mean of the per-bar ratios.
- Use positive summed true range for each window. Each component is then from zero to one, and the positive weights 4/7, 2/7 and 1/7 keep the final reading from zero to 100.
Ultimate Oscillator example and component weights
A stock closed the prior session at $100.00. Today it trades a high of $103.20, a low of $99.40, and closes at $102.60. Running sums of buying pressure and true range are already accumulated over the three windows.
- True low: the lower of the $99.40 low and the $100.00 prior close is $99.40; true high: the higher of the $103.20 high and the $100.00 prior close is $103.20
- Buying pressure: $102.60 − $99.40 = $3.20, against a true range of $103.20 − $99.40 = $3.80
- 7-period component: sum BP $14.40 / sum TR $24.00 = 0.600
- 14-period component: sum BP $25.20 / sum TR $48.00 = 0.525
- 28-period component: sum BP $43.20 / sum TR $96.00 = 0.450
- Weighted blend: 100 × [(4 × 0.600) + (2 × 0.525) + 0.450] / 7 = 100 × 3.90 / 7 = 55.71
The weighted components give 55.71, compared with 52.50 under equal component weights. Here the largest coefficient is applied to the largest component, 0.600, lifting the result. The inputs describe closes within extended ranges.
With prior close $100, high $103.20, low $99.40 and close $102.60, buying pressure is $3.20 and true range is $3.80.
The example’s accumulated components are 14.40 / 24 = 0.600, 25.20 / 48 = 0.525 and 43.20 / 96 = 0.450. Their weighted blend is 55.71. Equal component weights would give 52.50.
The windows overlap. If every bar has the same true range, the newest seven bars together contribute 75% of the final reading’s weight. The next seven contribute about 17.86%, and the oldest fourteen about 7.14%. The blend does not give each age group equal influence.
How gaps affect the Ultimate Oscillator
Because the calculation includes the preceding close, a gap changes the extended range. A close near today’s low can still be high within that extended range after a gap up.
For example, prior close $100, high $111, low $109 and close $109.20 give buying pressure $9.20 against true range $11. The ratio is 83.64%, even though the close is near today’s low.
Ultimate Oscillator divergence signals
Williams’s rules combine a qualifying threshold, divergence and oscillator structure break. Keep the selected swing points, threshold convention and recognition bar explicit.
In the chart, price falls from $98.60 at bar 6 to $98.00 at bar 11 while the corresponding UO readings rise from 29.59 to 37.45. Bar 12 reaches 42.93, above the intervening oscillator peak of 37.81. The recovery bar supplies the later confirmation of the second price low.
Choose the entry, invalidation, size and exit around the completed setup. Keep the 7/14/28 settings and session definition consistent. The worked 55.71 calculation and the chart teach separate examples of the same formula. On bar 12's break above 37.81, Options Flow shows whether calls are filling at the ask, and the Options Profit Calculator prices each bullish structure at the target and at the $98.00 second low.
Limitations of the Ultimate Oscillator
- Pair the reading with volume. Every input is a price distance, so buying pressure measures where closes sit in their true ranges, not how many shares traded or who traded them.
- Take entry timing from price. The windows are trailing sums, so the line reacts after price moves, and the overlap puts most of the weight on recent bars: 75% on the newest seven when true ranges are equal.
- Check for a gap before you read a high value. Gaps enter through the prior close, so a close near the day’s low can still read high, as the 83.64% example shows.
- Wait for the oscillator break before you trade a divergence. The three-window blend reduces early false divergences, and Williams’s rule adds the break of the intervening peak so the entry comes once the turn shows.
- Label the rule set you trade. Williams’s rules use 30 and 50 as entry gates and 70, 65 and 45 as exits and stops, some vendor versions change the short threshold, and a plain 70/30 overbought and oversold reading is a different rule.
Bottom line
The Ultimate Oscillator blends three windows of buying pressure into one weighted range-position reading that leans on recent bars. Keep the 7/14/28 settings fixed, use Williams’s full divergence-and-break rules rather than raw 70 and 30 levels, and define the entry, stop and exit before the signal appears.
Clear answers
Frequently Asked Questions
Sources and Further Reading
- Larry Williams: Ultimate Oscillator (author page)
- Larry Williams, The Ultimate Oscillator, Technical Analysis of Stocks and Commodities V.3:4 (140-141)
- Fidelity: Ultimate Oscillator Technical Indicator Guide
How entries are sourced, calculated and updated: editorial methodology.