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Key Takeaways
- A Fibonacci retracement measures one completed price swing and plots horizontal lines at fixed percentages of that swing, commonly 23.6%, 38.2%, 50%, and 61.8%.
- The tool is anchored by two points, the swing low and the swing high, so different anchor choices produce different levels on the same chart.
- The 61.8% and 38.2% ratios come from the Fibonacci sequence, and the 50% line marks the swing’s midpoint.
- Level spacing scales with the swing: a $40 swing spaces the internal levels $4.72 to $5.84 apart, and a $4 swing only $0.47 to $0.58.
- Define the price event that activates the setup, such as a completed close back above a selected level.
What is a Fibonacci retracement?
A Fibonacci retracement is a charting tool that measures how much of a selected price swing has been given back by plotting horizontal levels at fixed percentages of that swing. The common levels are 23.6%, 38.2%, 50% and 61.8%, plus the two endpoints, and traders use them as reference prices where a pullback can find support or resistance.
The grid answers a precise question: what percentage of the selected move has price given back?
How to calculate Fibonacci retracement levels
For an upswing, subtract ratio × (high − low) from the high. For a downswing bounce, add that product to the low.
The chart measures $100 to $140, a $40 range. Its levels are $130.56 at 23.6%, $124.72 at 38.2%, $120 at 50% and $115.28 at 61.8%.
These are arithmetic levels. On a logarithmic chart, set the tool’s scale to match, because the log grid places the same percentages at different prices on a large swing.
Formula
Range = swing high − swing low; Uptrend level = swing high − (ratio × range); Downtrend level = swing low + (ratio × range)- Ratio is the retracement percentage expressed as a decimal, commonly 0.236, 0.382, 0.500, and 0.618.
- Swing high and swing low are the two anchor extremes of the move being measured, chosen by the trader.
- These formulas measure arithmetic retracements. A three-anchor projection instead uses C + r(B − A), with C as the pullback anchor.
Worked Example
XYZ rallies from a swing low of $100.00 to a swing high of $140.00, then stalls. A trader anchors a Fibonacci retracement at those two extremes to map where the pullback could find buyers.
- Range: $140.00 − $100.00 = $40.00
- 23.6% level: $140.00 − (0.236 × $40.00) = $130.56
- 38.2% level: $140.00 − (0.382 × $40.00) = $124.72
- 50% level: $140.00 − (0.500 × $40.00) = $120.00
- 61.8% level: $140.00 − (0.618 × $40.00) = $115.28
Bar 15 trades down to $124.20, a 39.5% retracement, and closes at $124.90 above the $124.72 level. The following closes rise to $128.00, $131.50 and $134.50. The close back above the level is the entry trigger, and the $124.20 low marks the invalidation.
Where the Fibonacci ratios come from
In the Fibonacci sequence, each number is the sum of the previous two. Dividing by the number one, two or three places later settles near 0.618, 0.382 or 0.236.
The 50% line marks the exact midpoint of the measured swing and is included as a charting convention.
Level spacing scales with the swing. On a $4 swing, the gaps between the four internal levels shrink to $0.58, $0.47 and $0.47, so check that the distance clears the spread before you plan a setup around one level.
Fibonacci retracement example: a 38.2% reclaim
Bar 15 reaches a low of $124.20. The pullback depth is ($140 − $124.20) / $40 = 39.5%.
That bar closes at $124.90, back above the $124.72 level, the reclaim that triggers the long. The next three closes run to $128, $131.50 and $134.50.
Choose the trigger before entry: a touch, an intrabar cross or a close back above the level. Each fires at a different moment.
How to trade a Fibonacci retracement
Select the swing, the wick or closing-price convention, and the rule that confirms the two endpoints. Once both anchors are confirmed, the grid stays fixed for the trade.
Compare the chosen level with Support and Resistance and define entry, invalidation, position size and target. For targets based on a later pullback anchor, use the separate Fibonacci Extension construction.
Once price reclaims the level, Options Flow shows whether calls are being bought into the pullback, and the Options Profit Calculator prices the trade from the reclaim to your target with its breakeven and maximum loss.
Limitations of Fibonacci retracement
- Fix the anchors before you read a level. A different swing, or wick instead of closing-price anchors, produces a different grid on the same chart.
- The levels sit close together. On the $40 swing, adjacent internal levels are $4.72 to $5.84 apart, so a pullback that stops anywhere in the grid lands near one. Enter on the close back above the level, as bar 15 does at $124.90.
- Weight the levels that line up with prior support or resistance. The grid is arithmetic on the swing, so the confirmation comes from the chart’s own structure.
- Match the chart scale to your construction. Arithmetic and logarithmic scales give different levels on large swings, so the platform setting changes the prices.
- Name the trigger and the stop before entry. A touch, an intrabar cross and a close back above the level are different events, and a stop below the reaction low, $124.20 here, handles a pullback that cuts through the grid.
Bottom line
A Fibonacci retracement converts a completed swing into a grid of pullback prices at 23.6%, 38.2%, 50% and 61.8%. Fix the anchors and scale first, treat each level as a place to watch, and act on a defined price event such as a close back above the level.
Clear answers
Frequently Asked Questions
Sources and Further Reading
- Fidelity: What Is A Fibonacci Retracement?
- Fidelity: Fibonacci Fan Lines
- Fidelity: Support and Resistance
How entries are sourced, calculated and updated: editorial methodology.