Fibonacci Retracement

A drawing tool that marks proportional levels between a chosen swing high and swing low.

What it is

Fibonacci Retracement is a charting tool, not a calculated indicator like a moving average. You pick two points — usually a swing high and a swing low — and the tool draws horizontal lines at fixed percentages of that range: commonly 23.6%, 38.2%, 50%, 61.8%, and 78.6%. The 0% line sits at one end of the move and 100% at the other. Traders use these lines as reference areas to watch how price behaves after a move. The percentages come from ratios associated with the Fibonacci number sequence (the 50% line is a common addition that is not actually a Fibonacci ratio). It is educational and descriptive only — it does not predict price, it is not a buy or sell signal, and no indicator removes the risk of loss.

How it works

First you identify a price move you care about — a rally from a low to a high, or a drop from a high to a low. The tool measures the vertical distance between those two anchor points and places lines at set fractions of that distance. For an upmove, 0% is at the high and 100% at the low, so the levels show how far price has pulled back from the high toward the starting low. The math is simple: each level is the high minus the chosen percentage of the high-low range (or, for a downmove, the low plus that percentage). Because the result depends entirely on which two points you select, the same chart can produce very different levels for different traders. Nothing about the tool reacts to volume, momentum, or future bars — it only reflects the two anchors you chose, so the levels stay fixed until you re-anchor them.

How traders read it

• Traders often watch the 38.2%, 50%, and 61.8% levels as areas where a pullback might pause, since these are the most commonly referenced retracement zones — but watching is not the same as a signal to act.
• A move that stalls or reverses near a level is sometimes read as that area acting as temporary support or resistance, though this is an observation after the fact and never a guarantee of what comes next.
• Many traders treat the levels as zones rather than exact lines, because price rarely respects a single price to the tick.
• Some traders combine retracement levels with other context, such as a prior swing point, a trendline, or a moving average sitting in the same area, and view overlap as a level worth more attention.
• If price moves cleanly through a level without reacting, traders often read that as the level offering little influence for the current move.
• Levels shift the moment you re-anchor the tool to a different swing, so two charts of the same market can disagree — there is no single 'correct' set of levels.

Common settings

Standard levels are 23.6%, 38.2%, 50%, 61.8%, and 78.6%, with 0% and 100% at the anchors. Some traders add 88.6% or extension levels like 161.8% beyond the original move. The only real 'setting' is which swing high and swing low you anchor to.

Strengths

• Simple and transparent — every level is just a fixed percentage of a range you can verify by hand.
• Helps structure attention by marking a handful of reference areas inside a larger move.
• Works on any market and any timeframe because it only depends on the two anchor points you choose.
• Pairs naturally with other context (trendlines, prior swings, moving averages) when traders look for overlapping areas.

Pitfalls to watch

• Anchor selection is subjective. Different traders pick different swing highs and lows, so the 'levels' are not objective facts about the market.
• It is descriptive, not predictive. A level reacting in the past says nothing certain about future price, and no indicator removes the risk of loss.
• Hindsight bias is common — it is easy to point at levels that 'worked' after the fact while ignoring the many that price ignored.
• Over-plotting multiple retracements can fill a chart with lines until almost any price sits near 'a level,' making the tool meaningless.
• The 50% line is widely used but is not a true Fibonacci ratio; treating it as having special mathematical significance is a misunderstanding.
• If you auto-anchor to a rolling high/low (as in the example below), the levels re-draw as new bars arrive, so historical levels you see now may not match what was on screen at the time.

Pine v6 example

//@version=6
indicator("Fib Retracement (auto swing)", overlay = true)

length = input.int(100, "Swing lookback (bars)", minval = 2)

// Anchor to the highest high and lowest low over the lookback window
hi = ta.highest(high, length)
lo = ta.lowest(low, length)
rng = hi - lo

// Levels measured down from the swing high (common upmove convention)
level(ratio) => hi - rng * ratio

plot(level(0.0),   "0%",    color = color.gray)
plot(level(0.236), "23.6%", color = color.teal)
plot(level(0.382), "38.2%", color = color.teal)
plot(level(0.5),   "50%",   color = color.orange)
plot(level(0.618), "61.8%", color = color.teal)
plot(level(0.786), "78.6%", color = color.teal)
plot(level(1.0),   "100%",  color = color.gray)

Pro tip: Pick your two anchor points before you have an opinion about direction. If you find yourself re-dragging the tool until the levels line up with where you already wanted price to react, you are fitting the tool to your bias rather than reading the chart.

Educational only — not financial advice, not a recommendation to trade. No indicator is predictive; trading involves substantial risk of loss.