{"schemaVersion":"1.0","type":"BacktestEvidence","id":"https://formiq.jp/evidence/fibonacci-retracement-levels/data.json","evidencePage":"https://formiq.jp/evidence/fibonacci-retracement-levels","language":"en","article":{"title":"Does Fibonacci 61.8% Really Hold? 2 Years of USD/JPY Tested","url":"https://formiq.jp/blog/fibonacci-retracement-levels","published":"2026-08-26","updated":"2026-08-30"},"author":{"name":"Yuichi Saiki","alternateName":"斉木勇一","url":"https://formiq.jp/about/yuichi-saiki"},"verified":"2026-08-30","question":"Which Fibonacci retracement level actually holds, and is 61.8% special?","finding":"No ratio had an effect of its own. Measuring strength as the share of pullbacks that ended at the level, across 6,266 USDJPY swings 45% came first at 4.29%, then 50% at 4.27%, 61.8% at 4.22%, 78.6% at 3.95%, 38.2% at 3.94% and 23.6% at 2.73% — and the leader is not a Fibonacci ratio. The 61.8% level turned 4.22% while 62.0% turned 4.30% and 61.0% turned 4.22%; against the depths within three points either side the five Fibonacci ratios averaged −0.037 points and came out ahead in 31 of 60 cells. What did matter was depth: 23.6% was reached on 95.9% of swings, 38.2% on 87.2%, 50% on 78.8%, 61.8% on 71.4% and 78.6% on 62.3%. In trading, the 256 settings that bought the level won 61.17% of trades for a median of −629.1 pips a year, while the 217 that traded the break won 43.23% for +206.1 pips.","methodology":"Measured with Formiq's backtester. Swings are detected automatically — a bar beating the five bars on each side — and repeated at 3, 8, 13 and 21 bars as a sensitivity check. The turn rate is the share of swings reaching a depth whose pullback ended within 5 points of it, also computed at 2.5 and 10 points. Depths that are not Fibonacci ratios are mixed into the same grid as the control.","scope":["USDJPY, 2025-01-01 to 2025-12-31, with 2024 run identically for comparison","M15, H1 and H4; 6,266 swings (M15 4,752 / H1 1,176 / H4 338)","Depth grid 10.0% to 90.0% in 0.2% steps = 401 levels. Trading: 9 levels (5 Fibonacci, 4 controls) x 5 swing definitions x 2 triggers = 90 settings per timeframe per window","0.3 pip spread, 0.1 lots, zero slippage"],"keyResults":[{"label":"Share of pullbacks that ended at the level","value":"45% at 4.29%, 50% at 4.27%, 61.8% at 4.22%, 23.6% at 2.73%"},{"label":"Fibonacci ratios against the depths three points either side","value":"−0.037 points on average, ahead in 31 of 60 cells"},{"label":"Share of swings that reached each level","value":"95.9% at 23.6%, 87.2% at 38.2%, 78.8% at 50%, 71.4% at 61.8%, 62.3% at 78.6%"}],"limitations":["One pair, USDJPY, and two years. Nothing here guarantees the same behaviour on another pair or another period.","Swings are detected, not drawn. A person choosing anchors by hand may pick different waves, and this test cannot measure that choice. Five detection widths were run and the ordering did not change.","The 5-point window that counts as 'ended here' is arbitrary. It was also computed at 2.5 and 10 points, and the relationship between levels did not change.","The turn rate asks whether the pullback finished at the level. A pause that resumed lower is not counted as a turn.","The 401 depths overlap, so neighbouring figures are not independent. The maximum cannot be read as the result of 401 independent trials.","Entries and exits use bar closes, and the spread is held at 0.3 pips throughout."]}