What Is the Alligator Indicator? Bill Williams' Strategy Explained

The Alligator indicator is a trend-following technical tool developed by trader Bill Williams to help traders identify directional market momentum and avoid trading during flat, range-bound periods. It uses three smoothed moving averages with different time settings, each shifted forwards on the chart. Together, the lines are designed to resemble the behaviour of an alligator as it sleeps, wakes and feeds during changing market conditions.

Understanding how this tool works can help traders identify potential trend transitions while avoiding periods when false breakouts are more likely. This guide explains the indicator's structure, its four behavioural phases, how it can be applied to leveraged CFD trading, and some common mistakes to avoid.

How the Alligator Indicator Works: Jaw, Teeth and Lips

In his book Trading Chaos, Bill Williams argued that financial markets trend only 15% to 30% of the time and spend the remaining 70% to 80% moving sideways. To help filter out market noise during these sideways periods, the indicator uses three smoothed moving averages (SMMAs) based on the median price — (High + Low) / 2 — rather than the standard closing price.

Each line uses a different period and is shifted forwards on the chart:

• The Jaw (Blue Line): A 13-period SMMA shifted eight bars forwards. It acts as the slower structural baseline for the trend.
• The Teeth (Red Line): An 8-period SMMA shifted five bars forwards. It reflects intermediate momentum.
• The Lips (Green Line): A 5-period SMMA shifted three bars forwards. It represents short-term price momentum and reacts fastest to current price movements.

When short-term momentum changes, the faster Lips line can cross through the Teeth and Jaw lines, signalling a potential shift in market direction.

The 4 Phases of Market Behaviour

A key feature of this tool is its visual representation of changing market conditions. Williams used the analogy of an alligator moving from rest to activity to describe how markets can shift from low volatility into stronger directional movement.

1. Sleeping Phase

During the Sleeping phase, all three lines converge and become closely intertwined. This represents a range-bound or low-volatility market where buyers and sellers are in temporary balance.

Within Williams' framework, the longer the Alligator remains asleep, the stronger the eventual breakout is expected to be.

2. Awakening Phase

As the price begins to move out of its consolidation range, the green Lips line crosses above or below the red Teeth and blue Jaw lines. The three lines then begin to spread apart, signalling that the Alligator is waking and that a new trend may be developing.

3. Eating Phase

Once a trend is established, the three lines spread further apart and tend to move relatively parallel to one another.

In a strong bullish trend, the green Lips line remains above the red Teeth, while the blue Jaw stays below both. In a bearish trend, this order is reversed.

4. Sated Phase

As directional momentum begins to weaken, the lines start moving back towards each other. When the green Lips line crosses back over the Teeth line, the Alligator is considered 'sated', or full.

This phase suggests that the existing trend is losing strength and that the market may be moving back towards a range-bound condition.

Using the Alligator Indicator in CFD Trading: Costs and Whipsaws

Using trend-following indicators with leveraged CFD positions requires careful consideration of trading costs. CFDs let you gain market exposure using leverage, which increases both your potential profits and potential losses.

Because moving averages are calculated using historical price data, the Alligator is fundamentally a lagging indicator.

In sideways markets, lagging indicators can produce repeated false crossover signals, commonly known as whipsaws. Repeatedly opening and closing leveraged positions during a Sleeping phase can lead to accumulating trading costs:

• Bid-Ask Spreads: Each trade involves the spread between the bid and ask price, so frequent false entries can become costly over time.
• Overnight Swap Rates: Trend-following CFD positions held overnight can incur financing charges, or swaps. These costs can reduce overall account equity if a position is held while the expected trend fails to develop.
• Execution Slippage: Entering a breakout as the Alligator moves into its Awakening phase can result in slippage, where an order is filled at a less favourable price than expected during periods of sharp volatility.

Common Mistakes When Trading with the Alligator Indicator

You can end up with drawdowns if you misread how moving-average systems behave under different market conditions.

• Trading Inside the Sleeping Phase: Opening positions while the Jaw, Teeth and Lips are closely intertwined can expose traders to repeated whipsaws. Waiting until the lines begin to spread apart can provide clearer evidence that directional momentum is developing.
• Using the Indicator in Isolation: Relying only on line crossovers without additional analysis can lead to late or misleading entries. Combining the Alligator with momentum indicators such as the mfi indicator can help assess whether a price move is supported by volume or whether momentum is starting to fade.
• Chasing an Exhausted Trend: Opening a position when the lines are already widely separated and beginning to turn back towards one another — the Sated phase — can increase the risk of buying near the top or selling near the bottom of a market move.

In practice, most experienced chart readers use the Alligator as an execution filter rather than a standalone signal generator.

By using the indicator to identify periods when staying out of a flat market may be more appropriate, traders can preserve capital for conditions where clearer directional momentum is present.

Understanding the Alligator Indicator

This trading tool provides a structured visual method for assessing trend direction and changes in market volatility. By observing when the Jaw, Teeth and Lips move from an intertwined formation into a wider spread, traders can assess whether stronger directional momentum may be developing while avoiding some of the noise associated with sideways markets.

Combining the Alligator with other technical indicator and disciplined risk management can help reduce the impact of lagging or false signals. CFDs are complex, high-risk products, and leverage can cause losses to occur quickly. You should understand the relevant trading costs and manage your downside risk carefully before opening a position.