Ultimate Oscillator

Momentum

What it measures

The Ultimate Oscillator, developed by Larry Williams, combines buying pressure measured across three different timeframes (short, medium, long — default 7/14/28 periods) into a single weighted reading. It was specifically designed to fix a common flaw in single-timeframe oscillators like RSI: false divergence signals caused by looking at only one lookback window.

How readings are interpreted

Values range 0–100. Because it blends three timeframes, a genuine bullish or bearish divergence on the Ultimate Oscillator is considered more reliable than a single-timeframe RSI divergence, since it has to hold up across short, medium, and long lookbacks simultaneously rather than being an artifact of one arbitrary period choice.

Conventional levels

Above 70: overbought
Below 30: oversold
Bullish divergence (price makes a lower low, UO makes a higher low) + UO subsequently breaks above the high of the divergence: the classic Ultimate Oscillator bullish configuration
The reverse pattern (bearish divergence + break below) is its bearish counterpart
Because it blends three periods, extremes are somewhat rarer and more meaningful than on a single-period oscillator

Where it works, and where it does not

Works across most market conditions better than single-timeframe oscillators precisely because it isn't tied to one lookback, but it's still fundamentally a range-bound/reversal tool — in a powerful sustained trend it can stay pinned at an extreme for a long time without a genuine reversal materializing.

Commonly read alongside

RSI: Agreement between UO and RSI on a divergence signal adds confidence
Volume: A UO divergence signal confirmed by rising volume on the reversal bar is stronger
Support/Resistance: UO signals are more reliable when they occur at a pre-existing support or resistance level

Known limitations

The classic divergence-and-break signal pattern is comparatively rare — it produces comparatively few readings
Like all bounded oscillators, extended strong trends can keep it pinned near 70 or 30 without reversing
Blending three periods makes the calculation less intuitive to reason about at a glance than a single-period RSI

In practice

Best used specifically for its divergence-and-break signal pattern rather than simple overbought/oversold crosses
Because signals are rarer, this is better suited to swing/position trading watchlists than active day-trading scans
A trend filter is conventionally applied, with bullish divergence given weight only while price is above the 200-day SMA) to avoid fighting a strong downtrend
Wait for the actual break of the divergence high/low rather than acting the moment divergence appears — the break is the confirmation

Plot it yourself. Add this indicator to a chart, change every parameter and watch the line move, then backtest how the rule would have behaved on historical data — free on the S&P 500 ETF, no card.

Create a free account or start with the lessons →

This is reference material, not advice. It describes what each indicator measures and how its readings are conventionally interpreted. Nothing here is a recommendation to buy or sell anything, and no indicator predicts future prices. GU Analyser is an analytical tool — no money is ever traded here.