Alligator Indicator in Forex

What Is the Alligator Indicator?

The Alligator indicator is a trend-identification tool developed by trader and market theorist Bill Williams and introduced in his 1995 book Trading Chaos. It uses three smoothed moving averages (SMMAs), each calculated on the median price (rather than the close) and shifted forward in time. Williams named the three lines after the anatomy of an alligator — Jaw, Teeth, and Lips — with the metaphor of whether the alligator is sleeping (lines tangled), awakening (lines beginning to separate), or eating (lines fully spread and trending).

The core insight is simple but powerful: markets trend only a minority of the time — Williams estimated roughly 15–30% of all price action. The remaining 70–85% is sideways consolidation that produces losing signals for most trend-following systems. The Alligator’s design explicitly addresses this problem: it tells you when not to trade (sleeping phase) as directly as it tells you when a trend is active (eating phase).

The indicator is built into MetaTrader 4, MetaTrader 5, and TradingView as a standard tool and requires no manual calculation. Its value is not in the mathematics — three moving averages are trivially simple — but in the interpretive framework of phases and line order that Williams built around it.

The Alligator functions as a trend-state filter. It answers the binary question: is this market trending right now? It does not provide a standalone entry trigger, an exit level, or a volatility measurement. Used alone, it is an incomplete strategy. Used as a condition that must be met before acting on any other signal, it is a valuable noise filter.

Jaw, Teeth, and Lips Explained

Each line has a specific lookback period and a specific shift forward. The combination of different lookback and shift values gives the three lines their characteristic behaviour — the Lips reacts quickly, the Jaw is slow and steady, and the Teeth sits between them.

The Alligator Jaw (Blue Line)

Formula: 13-period SMMA of median price ((high + low) ÷ 2), shifted 8 bars forward.

The Jaw is the slowest line. Its 13-period lookback smooths out most short-term price noise, and the 8-bar forward shift means it appears ahead of the current bar — visually as if the line is projecting forward. In an uptrend, the Jaw is the lowest of the three lines; in a downtrend, the highest. It represents the broadest equilibrium and acts as the most distant dynamic support (uptrend) or resistance (downtrend) reference. When price pulls back far enough to test the Jaw, the move is considered a significant retracement relative to the trend’s overall structure.

The Alligator Teeth (Red Line)

Formula: 8-period SMMA of median price, shifted 5 bars forward.

The Teeth sits between the Jaw and the Lips in both speed of reaction and position. In an uptrend, it is above the Jaw and below the Lips. The gap between Teeth and Jaw is a rough measure of medium-term momentum — if the gap is growing, the trend is accelerating; if it is narrowing, the trend is losing energy. Shallow pullbacks in a healthy trend typically find support at the Teeth before resuming.

The Alligator Lips (Green Line)

Formula: 5-period SMMA of median price, shifted 3 bars forward.

The Lips is the fastest line. It responds most quickly to new price data and is usually the first to change direction when a trend reversal begins. In an uptrend, it is the highest of the three lines. The angle of the Lips relative to the Teeth gives an early read on whether short-term momentum is consistent with the prevailing trend direction.

Why median price, not close?

Williams deliberately used the median price (high + low) ÷ 2 rather than the closing price for all three calculations. This reduces the influence of closing-price anomalies — stops being run just before the close, or news spikes that affect only the close — and keeps the lines centred on the true midpoint of each bar’s trading range.

Why shift the lines forward?

Shifting the lines forward in time was Williams’ method of acknowledging that moving averages are inherently lagging. By projecting them forward, the indicator visually compensates for the lag, making the lines appear “ahead” of price rather than behind. The practical effect is that the spread between the current price and the future-projected lines gives a sense of how extended price is relative to its equilibrium.

Alligator Indicator Settings

The default Alligator settings are 13/8 (Jaw), 8/5 (Teeth), 5/3 (Lips) — the first number is the SMMA lookback period, the second is the forward shift. These are the values Williams published and the defaults in all major platforms.

The default 13/8/5 Jaw, 8/5/3 Teeth, 5/3/2 Lips settings follow a near-Fibonacci progression. Williams designed them this way intentionally. The ratios are part of the system’s structure. Adjusting any one line in isolation destroys the proportional relationship — if you widen the Jaw without widening the Teeth and Lips accordingly, the phase system loses its calibration.

On H4 and daily charts, the default settings produce the clearest phase transitions. On M15 and lower, the lines tangle and untangle so frequently that the sleeping/eating distinction becomes meaningless. Most practitioners who use the Alligator below H1 increase all periods proportionally — but at that point it is no longer the Williams Alligator in its designed form.

The Four Alligator Phases

Williams organised the Alligator’s behaviour into four named phases. The phases are the analytical heart of the system — understanding them is more important than any specific entry rule because they define when the indicator has any signal value at all.

Sleeping Alligator

The three lines are intertwined, crossing each other repeatedly with no clear separation. Price is consolidating — the market has no directional commitment. This is the phase where most trend-following systems generate losing signals. Williams’ explicit guidance: when the Alligator sleeps, do not trade.

The longer the sleeping phase, the more pent-up energy in the market. An extended consolidation followed by a sharp breakout typically produces one of the cleaner Awakening → Eating transitions, because the move has room to develop before the lines tangle again.

Awakening Alligator

The lines begin to separate. The Lips is typically the first to move away from the other two. The Teeth follows, and finally the Jaw. This is the warning phase — a trend may be developing. Williams’ approach was to use fractals (his separate indicator) as the entry trigger during the Awakening phase, rather than acting immediately on the separation alone. The risk is that the Awakening can fail and collapse back into a new sleeping phase. Reduced position size or waiting for confirmed line order is appropriate here.

Eating Alligator

The lines are clearly separated and in the correct order — Lips above Teeth above Jaw in an uptrend, or Jaw above Teeth above Lips in a downtrend. Price is above all three lines (uptrend) or below all three (downtrend). This is the phase where the Alligator produces its highest-quality signals. Full trend-following positions are appropriate when the eating phase is confirmed.

The gap between the lines is a live measurement of trend strength. Increasing gap = acceleration. Stable gap = steady trend. Narrowing gap = the trend is losing momentum (watch for Sated phase).

Sated Alligator

The lines begin to converge. The gaps between Lips, Teeth, and Jaw are narrowing. The Alligator has “eaten enough.” This signals trend exhaustion — the move is losing energy and the market may be returning to a sleeping phase. Williams’ guidance: begin taking profits and tighten stop-losses when the Alligator becomes sated. The Sated phase does not guarantee a reversal — the trend may simply pause before the Alligator awakens again. But it is an explicit warning to stop adding to positions and start protecting gains.

Line Order Signals

The order of the three lines is the primary directional signal of the Alligator system. Once the lines are separated (eating phase), their stacking order determines whether the bias is bullish or bearish.

Bullish line order

Lips above Teeth above Jaw, all spreading upward, price above all three lines. This is the confirmed bullish eating phase. Short-term momentum (Lips) is strongest, medium-term momentum (Teeth) confirms, and the broad trend direction (Jaw) supports. Price trading above all three lines adds further confirmation. The wider the gaps between lines, the stronger the trend.

Bearish line order

Jaw above Teeth above Lips, all spreading downward, price below all three lines. The exact mirror of the bullish order. The broadest structure (Jaw) is now highest, indicating the dominant equilibrium is bearish, with shorter-term momentum (Lips) confirming by sitting lowest. Price below all three lines adds directional confirmation.

Price crossing individual lines

Price crossing the Lips is a minor signal — the Lips is the most reactive line and crosses are frequent. Price crossing the Teeth is more significant; the 8-period SMMA is more stable. Price crossing the Jaw is the most structurally significant event — the 13-period SMMA represents the broadest equilibrium and a definitive break of it often signals a major trend change. Jaw crosses should be assessed in the context of the overall line order, not in isolation.

Alligator Trading Setups

The Alligator is primarily a condition indicator — it tells you whether conditions are right to trade, not exactly when to enter. Williams used his Fractal indicator as the entry trigger, but the Alligator’s phases and line order are compatible with any price-action based entry method.

The bearish checklist is symmetrical: Alligator eating (Jaw above Teeth above Lips), price below all three lines, lines sloping downward, entry trigger fires, stop above the Teeth or Jaw.

Pullback to Teeth — the core trade location

In a confirmed eating phase, price frequently pulls back to the Teeth line before continuing in trend direction. This represents a retest of medium-term equilibrium. A rejection at the Teeth — a bullish candle pattern holding above it in an uptrend — is one of the cleaner Alligator entry references. The Jaw, being slower and further away, acts as the ultimate support/resistance backstop. A deeper pullback to the Jaw is not necessarily a reversal signal but it does indicate the trend has weakened enough to test its broadest equilibrium.

Alligator vs MACD vs ADX

All three indicators can identify trending conditions, but from different analytical angles. They answer different questions in the trade decision process.

The Alligator and ADX are natural complements: the Alligator tells you whether a trend is present (via phase and line order); ADX tells you how strong it is (as a number). A combination of Alligator in eating phase + ADX above 25 is a stronger confirmation than either alone. Add the ATR to set the stop-loss distance and the combination covers trend state, strength, and risk calibration without adding redundant information.

Alligator Indicator Limitations

Not designed for ranging markets

The Alligator is a trend-following tool. When the market is ranging — as it is for the majority of any given session — the indicator produces its sleeping signal and yields no tradeable information. Some traders treat the extended sleeping phase as a setup for the eventual breakout, but the Alligator itself provides no signal about the direction the breakout will take. Direction must come from other analysis.

No quantified trend strength

The Alligator’s eating phase tells you a trend exists; it does not tell you how strong it is. Two eating phases can look identical on the chart while one is backed by ADX of 42 and the other is ADX of 26. Adding an ADX confirmation layer addresses this gap — use the Alligator for trend-state identification and ADX for strength verification.

Lagging by design

All three lines are smoothed moving averages shifted forward. They are inherently lagging. By the time the lines are clearly in eating order, a portion of the move has already occurred. This is a necessary feature of the system’s noise-filtering design — earlier entry during the awakening phase means less lag but more false signals. Traders must accept the lag trade-off or supplement the Alligator with a faster signal for timing.

Forward shifts distort visual assessment

Because the lines are projected forward, the visual distance between current price and the displayed line position is not the actual current distance — the lines shown ahead of the current bar represent where the indicator will be in the future, not where price is now relative to the line. Beginners frequently misread the chart by comparing current price to the forward-projected portion of the lines. Always read the Alligator values at the current bar only.

Poor on M15 and below

On short timeframes, the Alligator transitions between sleeping and eating so rapidly that the phase framework loses meaning. The indicator was designed for daily and swing-trading timeframes. On M1–M15, most practitioners find the lines produce noise rather than structure.

Common Mistakes with the Alligator Indicator

Frequently Asked Questions About the Alligator Indicator