A Fibonacci retracement is a set of horizontal levels drawn between a swing high and a swing low to show how far a price might pull back before the move resumes. The levels come from ratios that appear in the Fibonacci number sequence, most commonly 23.6, 38.2, 50, 61.8 and 78.6 percent. Traders place the tool on a chart, mark the levels and watch whether the price slows or turns near them.
This guide explains how the levels are drawn, works through the arithmetic with invented prices, and sets out how traders use them alongside other tools. It also explains why the levels should be treated as reference points. The sequence does not give the market a special mathematical property, and what any level does depends on the swing points chosen and on what the price does next.
Where do the ratios come from?
In the Fibonacci sequence, each number is the sum of the two before it, and the ratios between nearby numbers settle toward a few familiar values. The ratio of a number to the next one is about 0.618, and the ratio of a number to the one two places after it is about 0.382.
The 50 percent level is not part of the sequence, but it is commonly included because it marks the midpoint of the move. These are the origins of the levels. They are not evidence that the levels control prices.
Traders draw the tool from a clear swing low to a clear swing high in an uptrend, or from a swing high to a swing low in a downtrend. The levels are then measured back from the end of the move. In an uptrend, a 38.2 percent retracement sits 38.2 percent of the move's height below the high. The choice of the two swing points determines every level, so the same chart can produce different levels for two traders who chose different points.
How do you calculate the levels?
Each level is the high minus the chosen ratio multiplied by the height of the move. The worked example below uses invented prices. A stock rises from a swing low of 50 to a swing high of 80, which is a move of 30, and the retracement levels are measured down from 80. The figures are illustrative.
| Level | Calculation | Price |
|---|---|---|
| 23.6% | 80 − (0.236 × 30) | 72.92 |
| 38.2% | 80 − (0.382 × 30) | 68.54 |
| 50.0% | 80 − (0.500 × 30) | 65.00 |
| 61.8% | 80 − (0.618 × 30) | 61.46 |
| 78.6% | 80 − (0.786 × 30) | 56.42 |
The 50 percent level sits at 65, the midpoint of the move. A trader who expects a pullback to a retracement level would watch the price as it approaches 68.54, 65 or 61.46, looking for a slowdown, a reversal candle or a close back above the level. If the price moved through 61.46 and closed below 50, the retracement would have been deeper than many traders expect in a healthy trend, and the reading would change.
How do traders use the levels?
Traders often combine retracement levels with other tools, such as horizontal support and resistance, trendlines and moving averages. A level that lines up with several other reference points is more likely to draw attention than a level that stands alone on the chart.
For example, a 61.8 percent retracement that sits at a previous swing low, or close to a long-term average, gives a trader more reasons to watch the area.
The levels can also help plan the stop. A trader who buys near a 38.2 percent level may place the stop below the 61.8 percent level, so that a deeper pullback than expected invalidates the idea. That placement depends on the trader's own rule, and it can be tested the same way as any other stop. The key is that the levels define the trade in advance. They are not a promise that the price will respect them.
Why are the levels conventions?
The levels have no proven special property in the testing that this guide can point to. Many other reference points, such as previous highs, round numbers and moving averages, also attract attention, and the price often reacts to them. Fibonacci levels may be watched by many traders, and that attention could make some of them more relevant at certain times.
That is a possibility, not an established result. Whether a level works depends on the market, the timeframe and how the swing points were chosen, and it should be tested on past data before it is relied on.
The sensitivity to the swing points is a practical problem. Moving a swing low by a few percent changes every level. A trader who redraws the tool after the price has moved can always find a set of levels that seems to fit. To avoid this, record the swing points when the tool is first drawn, and do not adjust them later unless there is a clear reason that you have written down.
How do you choose the swing points?
The swing points define every level, so choosing them is the most important step. Use a swing low and a swing high that are clearly visible, meaning the price turned sharply at each one and the move between them is large enough to matter.
Write the rule down before you draw, because the same chart can produce different levels for different choices.
A common approach uses the most recent significant swing, but significance is a judgement. A small wiggle inside a larger move is usually the wrong anchor, because it produces levels with little meaning for the broader trend. Some traders anchor to a major high or low visible over several months, which produces wider levels that are touched less often but may carry more weight.
Check the chart after drawing. If moving the anchor by a few percent changes the levels enough that the trade would look different, the tool is too sensitive for the decision you want to make. In that case, use a wider zone around each level, or choose a different reference point altogether. A tool that is only correct for one exact choice of anchor is not giving you information.
Common mistakes
Treating a level as exact. A level is an area. A price that stops a few percent from the line may still be respecting it.
Redrawing the swing points to fit the chart. If the levels move every time the price moves, the tool is describing the chart rather than anticipating it.
Using the tool without a stop or a plan. A retracement level is a reason to watch, and the trade needs a rule for being wrong.
Checklist
- Choose the swing high and swing low by a clear rule, and write them down.
- Draw the levels and note the price at each one.
- Check whether any level lines up with another reference point, such as a prior high or a moving average.
- Wait for a reaction at the level, such as a reversal candle or a close back above it, before acting.
- Set the stop at a level defined in advance, not one chosen after the trade.
- Test the approach on past charts, including the pullbacks that went deeper than the levels.
- Keep the swing points fixed for each trade, so that the record can be checked later.
Key takeaways
Fibonacci retracement levels are drawn from a swing high and low at ratios such as 38.2, 50 and 61.8 percent. They are measured from the move and then watched as possible points of support or resistance. The levels depend on the swing points, have no proven special property in the testing this guide can point to, and work best as one reference among several. Write the rules before you draw the tool, and test them before you rely on them.
This guide is for general information, not financial advice. See the disclaimer.