You are watching the Alligator Indicator and all three lines have fanned apart. The trend looks strong. But here is the question most traders skip: is the separation between those lines still growing, or has it already peaked and started to narrow? The Alligator itself does not answer that clearly. The Gator Oscillator does.
Bill Williams designed the Gator Oscillator as a companion to his Alligator. Where the Alligator plots three smoothed moving averages on the price chart, the Gator strips the price away entirely and shows you only the distance between those lines as two histograms. One above zero, one below. Green bars when the gap is widening. Red bars when it is shrinking. That simplicity is its entire value.
I started paying attention to it after I noticed a recurring pattern in my own trading. I would enter on a clean Alligator crossover, ride the move for a while, then give back profit because I could not tell from the Alligator lines alone when the trend was losing steam. The lines were still apart, still “eating,” but the rate of separation had already reversed. The Gator histogram made that visible at a glance.
What the Gator Oscillator Actually Measures
The Gator Oscillator takes the three Alligator lines (Jaw, Teeth, Lips) and calculates two values:
Upper histogram = absolute value of (Jaw – Teeth)
Lower histogram = negative absolute value of (Teeth – Lips)
The upper histogram always plots above the zero line. The lower histogram always plots below it. This is not directional. The Gator does not tell you if the trend is bullish or bearish. It tells you whether the Alligator’s lines are spreading apart or coming together, and how fast.
Each bar is color-coded by comparison to the previous bar. If the current bar is wider (further from zero) than the prior bar, it is green. If it is narrower (closer to zero), it is red. Some platforms use different colors, but the logic is the same: expanding versus contracting.
For reference, the Alligator’s default smoothed moving averages are:
Jaw: 13-period SMMA, offset 8 bars forward.
Teeth: 8-period SMMA, offset 5 bars forward.
Lips: 5-period SMMA, offset 3 bars forward.
The Gator inherits these settings. There is nothing extra to configure.
The Four Phases of the Gator
Williams described four states. Understanding them is the entire point of the indicator.
Gator Sleeps. Both histograms show red bars, contracting toward the zero line. The Alligator’s lines are intertwined or very close together. There is no trend. Price is ranging. This is where most false signals happen if you try to force a directional trade.
Gator Awakens. One histogram turns green (expanding) while the other remains red. This is the earliest signal that a trend might be forming. One pair of Alligator lines has started to separate, but the full structure is not aligned yet. Think of it as the first crack in a consolidation.
Gator Eats. Both histograms show green bars, expanding away from zero simultaneously. The Alligator’s lines are fanning out in order. This is the active trending phase and where trending trades have their best odds. The eating phase is what you want to be in.
Gator Sated. Both histograms turn red again, contracting back toward zero. The trend is losing momentum. The Alligator lines are still separated (you might still see an uptrend or downtrend on the chart), but the rate of separation has reversed. This is where I pay the most attention. It does not mean “exit now” in every case, but it means the easy part of the move is likely over.
How the Gator Differs from the Alligator
This trips up a lot of people because the two share the same underlying data. If they use the same moving averages, why bother with a separate indicator?
The Alligator shows you the current state. Lines crossed upward, trend is bullish. Lines intertwined, no trend. That is useful but binary. You are either trending or not.
The Gator shows you the rate of change of that state. It answers a different question: is the trend accelerating or decelerating? Two lines can still be separated (Alligator says “trend in progress”) while the Gator is already flashing red on both histograms (momentum fading). By the time the Alligator lines actually cross back and signal the end, you have often given back a significant portion of the move.
I think of it like a car speedometer versus an accelerometer. The Alligator tells you how fast the car is going. The Gator tells you whether you are pressing the gas or the brake. Both are useful, but they answer different questions. Using only the Alligator is like driving with only a speedometer. You know you are going 80, but you do not know if you are still accelerating or already slowing down.
Practical Interpretation on a Chart
Here is how I actually use it. Start by looking at the Gator first, then the price chart. Not the other way around.
When both histograms are red and flat near zero, I am not looking for trend trades. Period. This is the sleeping phase. I have learned the hard way that trying to anticipate the breakout during a sleep phase leads to whipsaws. The Alligator lines will be tangled, price will be chopping sideways, and any indicator signal you get from something like the Awesome Oscillator will likely be a false positive.
When one histogram turns green, I start paying attention but do not act. This awakening phase is a heads-up. I watch for the second histogram to follow. If it does, and both turn green, I look for an entry in the direction of the Alligator’s line order (Lips above Teeth above Jaw for bullish, or the reverse for bearish).
During the eating phase (both green), I hold existing positions and trail stops. I do not add new positions once the eating phase has been running for several bars because the best risk-reward is at the start of the expansion, not in the middle.
When the first histogram flips to red while the other is still green, that is my early warning. The sated phase is beginning. I tighten stops. If both flip to red, I look for the exit. Not always immediately, because sometimes a brief contraction precedes a second expansion leg. But I am no longer giving the trade wide room to breathe.
Where Traders Get the Gator Wrong
The most common mistake is treating the Gator as a standalone entry signal. It is not. Williams designed it as a confirmation tool for the Alligator system. Using the Gator without the Alligator is like reading a footnote without the text it references. The histogram expansion tells you that something is happening, but it does not tell you which direction. You need the Alligator’s line order for that.
The second mistake is acting on the awakening phase too aggressively. One green histogram does not mean a trend has started. It means one pair of moving averages is separating. I have seen plenty of awakenings that go right back to sleep. Waiting for both histograms to turn green improves the quality of signals significantly, even if it means entering a few bars later.
The third mistake is ignoring the timeframe. On a 5-minute chart, the Gator will cycle through all four phases multiple times a day, generating noise. On a daily chart, a full sleep-to-eat-to-sated cycle might take weeks. I find the Gator most useful on the 4-hour and daily timeframes where the phases have enough duration to be tradeable. Below that, the whipsaws outweigh the signal.
A fourth mistake specific to Bill Williams indicators in general: traders modify the smoothing periods without understanding the consequences. The Gator’s value comes from matching the Alligator exactly. If you change the Alligator’s settings, the Gator must change identically. If your platform lets you set Gator parameters independently of the Alligator, make sure they match. Mismatched settings give you a histogram that measures something different from what is on your chart.
Combining the Gator with the Accelerator Oscillator
Williams built a family of indicators, and they work best together. The Accelerator Oscillator (AC) measures the deceleration or acceleration of the Awesome Oscillator, which is itself derived from the median price. So you have a chain: price feeds the Awesome Oscillator, which feeds the Accelerator Oscillator. Meanwhile, the Alligator and Gator track the smoothed median price structure.
Here is the combination I find most reliable. When the Gator is in the eating phase (both histograms green) and the Accelerator Oscillator has two consecutive bars of the same color above or below zero in the trend direction, that is a strong confluence signal. It means the trend is expanding (Gator), momentum is accelerating (AO implied), and the rate of momentum change is confirming (AC). Three independent readings from the same system pointing the same way.
When the Gator starts going sated and the Accelerator Oscillator also starts printing opposite-color bars, the trend is losing steam on multiple fronts. That is when I close or heavily reduce positions.
Realistic Use Cases
Trend entry timing. You spot a potential breakout on the Alligator. The lines have just uncrossed. Rather than entering immediately, you check the Gator. If only one histogram is green, you wait. If both are green and expanding, you enter. This filter alone would have kept me out of at least a third of the false breakout trades I took before I started using it.
Exit timing. You are in a trending trade and the Alligator lines are still separated. The trend looks intact. But the Gator shows both histograms have flipped red. The separation is narrowing. This does not guarantee the trend is over, but the probability of a pullback or consolidation has increased. Time to trail stops tight or take partial profit.
Ranging market filter. Before looking for any trend-following setup, check the Gator. If both histograms are red and near zero, the market is sleeping. Save your energy and capital for when it wakes up. This sounds obvious, but I have burned more money fighting sleeping markets than I would like to admit.
Multi-timeframe confirmation. Check the Gator on the daily chart to confirm the broader trend is in an eating phase, then drop to the 4-hour chart for entries. If the daily Gator is sated or sleeping, trending trades on lower timeframes have a higher failure rate regardless of what the lower-timeframe Gator shows.
What the Gator Cannot Do
It does not give you direction. I keep repeating this because it is the single biggest source of confusion. Green bars do not mean bullish. Red bars do not mean bearish. The colors refer to expansion and contraction only.
It does not work well in choppy, low-volatility environments where price whipsaws through the Alligator’s lines repeatedly. In those conditions, the Gator will alternate between sleeping and brief awakenings that never reach the eating phase. If you see that pattern, you are looking at a ranging market and the Gator is telling you exactly that. Listen to it.
It is not a volume indicator. It does not account for participation, only for the relationship between smoothed moving averages of median price. Combining it with a volume tool can help confirm whether an expansion phase has real participation behind it or is just a thin-market drift.
When the Gator Earns Its Place on Your Chart
If you already use the Alligator Indicator, the Gator is the missing piece. It answers the question the Alligator cannot: is the trend still gaining strength, or is it fading? That single piece of information changes how you manage both entries and exits.
If you do not use the Alligator at all, the Gator on its own has limited value. It is a support tool for a specific system. Bolting it onto a completely different strategy (say, RSI divergences or Bollinger Band squeezes) will not add much because the histograms are measuring the internal dynamics of the Alligator’s moving averages, not general market momentum.
For traders already running the Williams system, the Gator takes the guesswork out of trend phase identification. Sleep, awaken, eat, sated. Four words. One histogram display. No ambiguity about whether momentum is expanding or contracting. That clarity, in my experience, is worth more than any complex multi-indicator overlay.
Educational content only. Not investment advice. Trading involves risk. You are responsible for your decisions.