CluenexWhat is a Fibonacci retracement?
A Fibonacci retracement is a set of horizontal lines drawn between a swing low and a swing high. Each line marks a percentage of the prior move that price might give back before the trend resumes.
The idea comes from the Fibonacci sequence, but there is no proven law of markets behind it. It is a popular drawing tool, not a measured rule of price behavior.
Where do the Fibonacci ratios come from?
The sequence runs 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, and each number is the sum of the two before it. Divide a number by the one after it and the result approaches 0.618, called the golden ratio, as the numbers grow. For example, 34 / 55 = 0.618.
The other ratios come from related divisions:
| Ratio | Where it comes from |
|---|---|
| 23.6% | A number divided by the number three places later, such as 13 / 55 |
| 38.2% | A number divided by the number two places later, such as 21 / 55, and also 1 minus 0.618 |
| 50% | Not Fibonacci. It is the midpoint, added because traders and Dow Theory commonly watch half retracements |
| 61.8% | A number divided by the next one, such as 34 / 55 |
| 78.6% | The square root of 0.618 |
How do you calculate retracement levels?
For an uptrend, subtract the ratio times the size of the move from the swing high. For a downtrend, add it to the swing low.
Worked example with a swing low of $100 and a swing high of $200, a move of $100:
| Level | Calculation | Price |
|---|---|---|
| 23.6% | $200 - ($100 x 0.236) | $176.40 |
| 38.2% | $200 - ($100 x 0.382) | $161.80 |
| 50% | $200 - ($100 x 0.50) | $150.00 |
| 61.8% | $200 - ($100 x 0.618) | $138.20 |
| 78.6% | $200 - ($100 x 0.786) | $121.40 |
If a stock then falls from $200 to $162, it has given back about 38% of the move. Charting software draws these lines automatically once you pick the two points.
How do you pick the swing points?
Use the most recent clear swing low and swing high on the timeframe you care about. A swing high is a peak with lower prices on both sides, and a swing low is a trough with higher prices on both sides.
This is the weak spot of the method. Two people can choose different swings on the same chart and get different levels. Longer timeframes, such as daily and weekly charts, produce fewer and less noisy swings than 1-minute charts.
What does each level suggest?
The common reading is simple: the deeper the pullback, the weaker the prior trend looks. Think of this as a way to describe a pullback, not predict it.
- 23.6% to 38.2%: a shallow pullback. Buyers stayed in control.
- 50%: a moderate pullback, half the move erased.
- 61.8% to 78.6%: a deep pullback. Much of the move is gone, and a fall below 78.6% is usually read as the trend failing.
- Beyond 100%: price has passed the start of the move, so the original swing no longer applies and the levels should be redrawn.
Do Fibonacci retracements actually work?
There is no solid evidence that price reverses at these levels more often than at other levels. Claims of exact bounce rates, such as 60% to 70%, are not backed by published research, and none are used here.
Two reasons explain why prices sometimes seem to respect them. First, many traders watch the same lines, so orders can cluster there. Second, with five or more levels on a chart, price is always near one of them, and people remember the hits more than the misses. Studies of technical analysis in general have found mixed results, and profits often shrink after trading costs. See the sources for investor education on technical analysis.
Where do Fibonacci retracements fail?
They fail whenever the swing is ambiguous, the trend is not clear, or news changes the picture. A level does not know about earnings, interest rates or a lawsuit.
Common mistakes:
- Treating the line as exact. Price rarely stops at $138.20. If a bounce at $140 counts and a bounce at $135 counts, nearly any outcome fits the theory.
- Drawing too many levels. With five lines, something always lines up. Decide the levels before looking at price.
- Redrawing after the fact. Moving the swing points until the chart looks right is hindsight, not analysis.
- Ignoring the bigger trend. A pullback in a falling market is not the same as a pullback in a rising one.
- Relying on one tool. Combining several chart tools that all depend on the same price history adds less information than it appears to.
How do Fibonacci levels compare with other chart tools?
Fibonacci levels are projected from two points you choose. Support and resistance lines come from prices where the market actually turned before. Moving averages come from a fixed formula, so two people get the same line. See Support and Resistance Levels and Moving Averages Explained for those.
If a Fibonacci level lands at a spot where price has turned before, that overlap is more meaningful than the ratio alone, because earlier turns are real history.
What this means for you
If you have a regular job and a brokerage account, treat Fibonacci lines as a way to frame a pullback, not as a reason to buy or sell. A stock sitting at a 61.8% line is not a bargain, and one slicing through it is not necessarily broken.
Practical habits:
- Decide what you own and why from the business first. A price level cannot tell you what a company is worth.
- Use a chart level, if at all, to decide how much to buy at once, or to set a point where you will re-check your thesis. See Position Sizing.
- Write down your swing points before the pullback, so you cannot move them afterward.
- Do not trade on any claimed bounce rate you cannot trace to a published test.
Cluenex shows charts with common technical indicators and harmonic pattern zones, but treats chart patterns as context, not as buy or sell signals, because its own tests found no reliable directional edge in them. Its verdicts on stock pages come from fair value work, described at how Cluenex values stocks.