Awesome Oscillator (AO)

A momentum histogram that compares a short-term and a longer-term average of price.

What it is

The Awesome Oscillator (AO) is a momentum indicator developed by Bill Williams. It gauges market momentum by comparing a recent average of price against a longer-term average. Both averages are calculated from the "median price" of each bar (the high plus the low, divided by two), rather than the close. AO is drawn as a histogram that oscillates above and below a zero line, with bars typically colored green or red depending on whether each value is higher or lower than the one before it. It ships as a built-in indicator on most charting platforms; on TradingView it can also be reproduced in Pine Script using the ta.sma() function on hl2.

How it works

For each bar, AO first finds the median price, which is simply the high plus the low divided by two (the built-in hl2 in Pine Script). It then takes a 5-period simple moving average of that median price and subtracts a 34-period simple moving average of the same median price. The result is plotted as a histogram around zero. When the fast (5-period) average is above the slow (34-period) average, AO is positive and bars sit above the zero line; when the fast average is below the slow one, AO is negative and bars sit below zero. The 5/34 lengths are the defaults Bill Williams specified and are what most platforms use out of the box.

How traders read it

• Zero line: traders often read AO crossing above zero as short-term momentum turning more positive than the longer-term average, and crossing below zero as the opposite. This describes a momentum state, not a trade signal.
• Bar color: a green bar means the current AO value is higher than the previous bar's, and a red bar means it is lower. Many traders watch color changes as a way to gauge whether momentum is building or fading.
• Histogram height and distance from zero are commonly interpreted as the relative strength of momentum at that moment.
• The 'saucer' setup is a frequently cited pattern: a sequence of bars on the same side of zero that dip and then turn back, which some traders view as a momentum pause and resumption.
• Divergence: when price makes a new high or low that AO does not confirm, some traders treat it as a sign that momentum may be weakening. Divergence is interpretive and frequently fails to lead to any reversal.
• No indicator is predictive. AO describes past and current momentum only, and all trading carries risk of loss.

Common settings

Default lengths are 5 (fast) and 34 (slow), both applied to the median price (high+low)/2, as Bill Williams defined. These are the standard settings on most platforms; some traders experiment with other lengths, but the 5/34 pair is the conventional baseline.

Strengths

• Simple and transparent: just the difference between a 5-period and 34-period average of median price, so it is easy to understand and reproduce.
• The histogram and color coding give a quick visual read of momentum direction and whether it is strengthening or weakening.
• Uses median price rather than close, which some traders prefer because it reflects the full bar's range.
• Available natively on most platforms with standard 5/34 settings, so behavior is consistent and well documented.

Pitfalls to watch

• AO is built from moving averages, so it lags price and reacts after a move is already underway. It does not call tops or bottoms in advance.
• In ranging or choppy markets, AO can cross zero and flip bar colors repeatedly, producing many whipsaw changes that are easy to over-interpret.
• Divergence between AO and price is unreliable on its own; momentum can diverge for a long time without any reversal occurring.
• Because it uses median price ((high+low)/2) rather than the close, AO can read differently from close-based momentum tools, so values are not directly comparable across indicators.
• AO is a descriptive input only and offers no probability or edge by itself. It is one of many tools a trader might consult, not a standalone basis for decisions.

Pine v6 example

//@version=6
indicator("Awesome Oscillator", shorttitle="AO")

medianPrice = hl2
ao = ta.sma(medianPrice, 5) - ta.sma(medianPrice, 34)

// green when current value is at or above the prior bar, red when below
aoColor = ao >= ao[1] ? color.green : color.red

plot(ao, title="AO", style=plot.style_histogram, color=aoColor)
hline(0, title="Zero", color=color.gray)

Pro tip: AO is most often used as a context tool rather than in isolation. Traders commonly look at the zero-line position, bar color changes, and the overall trend together, and compare what AO shows against price structure on the chart instead of reacting to any single AO event. This is educational context, not a recommendation to trade.

Educational only — not financial advice, not a recommendation to trade. No indicator is predictive; trading involves substantial risk of loss.