What is Alligator?
The Williams Alligator draws three smoothed moving averages of the median price, each shifted a few bars to the right. The jaw is the slowest (21 bars, shifted 8), the teeth sit in the middle (13 bars, shifted 5) and the lips are the fastest (8 bars, shifted 3). The reading is the shape: lines tangled together suggest a market without direction, lines fanned out in order suggest a trend, and the order of the lines says which way.
The shift does not make the lines predictive. Each value is the same average calculated on its own bar, only drawn further to the right so it is easier to compare with later price. The Alligator does not forecast price or measure trend strength in any fixed unit.
How to use Alligator
- Lines tangled. When the jaw, teeth and lips are wound around each other, the averages agree on one level and the market has no clear direction.
- Lines fanned out in order. Lips above teeth above jaw, with space between them, is the uptrend picture. Lips below teeth below jaw is the downtrend picture.
- Lines starting to separate. The lips moving away from the other two first, followed by the teeth, is the sequence of a move getting under way.
- Lines coming back together. As a trend fades, the gaps narrow and the lines start to cross. That is the picture of the move losing momentum.
These are ways to read the lines, not entry signals on their own.
Settings
| Setting | Default | What it changes |
|---|---|---|
| Jaw Length | 21 | Bars in the jaw's smoothed average, the slowest line. Minimum 1. |
| Jaw Offset | 8 | How many bars the jaw is shifted to the right. Negative values shift it left. Range -500 to 500. |
| Teeth Length | 13 | Bars in the teeth's smoothed average, the middle line. Minimum 1. |
| Teeth Offset | 5 | How many bars the teeth are shifted to the right. Range -500 to 500. |
| Lips Length | 8 | Bars in the lips' smoothed average, the fastest line. Minimum 1. |
| Lips Offset | 3 | How many bars the lips are shifted to the right. Range -500 to 500. |
The source is fixed to the median price, hl2, and has no input.
Calculation
Each line is a smoothed moving average (Wilder's smoothing) of the median price, then drawn a set number of bars to the right:
median price = (high + low) / 2
SMMA = (previous SMMA * (length - 1) + median price) / length
jaw = SMMA(median price, 21), drawn 8 bars right
teeth = SMMA(median price, 13), drawn 5 bars right
lips = SMMA(median price, 8), drawn 3 bars rightEach line starts from the simple average of its first full window and from the next bar the recursion takes over. The smoothing factor is 1/length, slower than an EMA of the same length, the same method as the standalone Smoothed Moving Average.
The offset only changes where a value is drawn, not what it is. The chart cannot draw past the last bar, so each line stops at the right-hand edge instead of extending 8, 5 or 3 bars beyond it. Everything drawn over real bars is correct; only that leading tip is missing.
Limitations
- It lags. Smoothed averages are slow by design, and the forward shift does not change that. A trend is well under way before the lines fan out.
- The leading tip is not shown. The last few bars of each shifted line would sit beyond the latest candle, and those are not drawn.
- Tangled is a judgement. The indicator draws no threshold for when lines count as tangled or fanned, so the reading is by eye.
- Sideways markets produce repeated crossings. In a range the three lines cross often without a trend following.
- It is not a strategy. On its own it carries no risk management, sizing or exit.
Frequently asked questions
It is three smoothed moving averages of the median price, called the jaw, teeth and lips, with lengths 21, 13 and 8 and shifted 8, 5 and 3 bars to the right. It is read by whether the lines are tangled or fanned out in order.
Tangled lines suggest no clear direction. Lips above teeth above jaw with clear gaps is the uptrend picture, the reverse order the downtrend picture. Narrowing gaps and crossings suggest a trend is fading.
Yes. The indicator declares six inputs: Jaw Length 21, Jaw Offset 8, Teeth Length 13, Teeth Offset 5, Lips Length 8 and Lips Offset 3. Lengths have a minimum of 1; offsets range from -500 to 500. The source is fixed to the median price, hl2.
Values on closed bars are not revised. The shift moves where each value is drawn but does not change it. With positive offsets the live candle's own values would be drawn to the right of the last candle, so they are not shown; what is drawn up to the right-hand edge comes from bars that have already closed. Loading older history recalculates the smoothed averages and values near the start of the loaded range can shift.
With a forward shift, the newest values belong to bars that have not formed yet. The chart cannot draw past the last bar, so those leading values are not shown. Everything over existing bars is drawn correctly.
Use the Add to chart button at the top of this page. It opens BTC/USDT on Binance in the Altrady Charts terminal with the built-in Williams Alligator already applied. On any other market, open the indicator picker on the chart and choose Williams Alligator from the Moving Average group.