Fibonacci retracement levels explained: 38.2%, 50% and 61.8%
Fibonacci retracements mark where a pullback might pause by cutting a prior move at 23.6%, 38.2%, 50%, 61.8% and 78.6% of its length.
What Fibonacci retracements are
After a strong move, prices rarely continue in a straight line — they pull back before the trend resumes or fails. Fibonacci retracements are horizontal levels that divide the previous move into proportions taken from the Fibonacci sequence (0, 1, 1, 2, 3, 5, 8, 13, 21, …), in which each number is the sum of the two before it.
Divide any number in the sequence by the next one and the result approaches 0.618; divide it by the number two places further on and you get about 0.382, three places on about 0.236. Those ratios, plus 50% and 78.6% (the square root of 0.618), became the standard retracement levels.
How the levels are calculated
Pick a meaningful swing low (L) and swing high (H). For a pullback within an uptrend:
Level = H − (H − L) × ratio ratios: 0.236 · 0.382 · 0.5 · 0.618 · 0.786
In a downtrend you measure from the high down to the low and add instead: level = L + (H − L) × ratio. The reference-levels card on our asset pages does this automatically over the recent high–low range and adds extensions beyond both ends.
A worked example
A stock climbs from 100 to 150, a move of 50. The retracement levels are 150 − 50 × 0.236 = 138.2; 150 − 50 × 0.382 = 130.9; 150 − 25 = 125 (the 50% level); 150 − 50 × 0.618 = 119.1; and 150 − 50 × 0.786 = 110.7. A shallow pullback that holds near 138 or 131 suggests a strong trend; a drop through 119 and then 111 means most of the advance has been given back, and many traders would start to doubt the uptrend.
Traders look for confluence: if the 61.8% level at 119 also coincides with an old resistance level and the 200-day moving average, it is a far more credible zone to watch than a Fibonacci line on its own.
Limitations and common mistakes
The result depends entirely on which high and low you choose, and different choices give different levels — so in hindsight it is always easy to find a level that 'worked'. There is no robust evidence that markets respect these particular ratios more than any others; much of their effect is probably self-fulfilling, because many participants watch the same lines.
Treat the levels as a map of where a reaction is plausible, not as predictions. Look for confirmation — a reversal candle, a momentum shift on RSI or MACD, rising volume — and decide in advance where you would be wrong.
Frequently asked questions
What is the most important Fibonacci retracement level?
The 61.8% level, often called the golden ratio, is the most watched, followed by 38.2% and 50%. None is reliable on its own; they matter most when they coincide with other support or resistance.
Is 50% a Fibonacci number?
No. The 50% retracement comes from older market theory — the observation that prices often give back about half of a move — but nearly every platform shows it alongside the Fibonacci ratios.
What is the difference between a retracement and an extension?
Retracements sit inside the previous move and estimate where a pullback might stop. Extensions, such as 127.2% or 161.8%, project beyond it and are used to estimate where a trend might run next.