{"schemaVersion":"1.0","type":"BacktestEvidence","id":"https://formiq.jp/evidence/bollinger-band-settings/data.json","evidencePage":"https://formiq.jp/evidence/bollinger-band-settings","language":"en","article":{"title":"Bollinger Bands: Mean Reversion or Breakout? 315 Settings Tested","url":"https://formiq.jp/blog/bollinger-band-settings","published":"2026-08-25","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":"Traded both ways, does fading or breaking out of the Bollinger bands keep the money?","finding":"The higher win rate lost and the lower one won. On USDJPY hourly bars the long fade had a 60.4% mean win rate but was profitable in both 2024 and 2025 in only 25 of 140 settings, and the short fade in 0 of 140. The breakout, at a 40.4% mean win rate, was profitable in both years in 23 of 35 settings. The cause is the asymmetry of the two sides: averaged over every hourly setting in 2025 the fade won 41.3 pips and lost 68.6, while the breakout won 123.8 and lost 80.9. The textbook period 20 at 2σ reversed with the rule as well — traded as a fade it made 71.0 pips in 2025 and lost 597.6 in 2024 on the hourly chart, and traded as a breakout it made 1,177.5 and 1,434.6 pips.","methodology":"Measured with Formiq's backtester. The fade buys at the close of a bar whose low touched the lower band and exits at the close of a bar whose high touched the upper band. The breakout buys when a close clears the upper band and sells when a close clears the lower one, reversing on the same bar that closes beyond the opposite band. No stop or target in the main sweep.","scope":["USDJPY, 2025-01-01 to 2025-12-31, with 2024 run identically for comparison","15-minute, hourly and four-hour bars; 24,903 15-minute bars in 2025, 6,226 hourly and 1,610 four-hour","Fade: 7 periods (10 to 50) x 5 deviations (1 to 3σ) x 4 exit deviations (0.5 to 2σ) = 140 settings, run separately for each side. Breakout: 7 periods x 5 deviations = 35","Flat 0.3 pip spread, 0.1 lots, no slippage"],"keyResults":[{"label":"Profitable in both years on hourly bars","value":"long fade 25 of 140, short fade 0 of 140, breakout 23 of 35"},{"label":"Mean win rate","value":"60.4% for the long fade, 40.4% for the breakout"},{"label":"Average win and loss on hourly bars in 2025","value":"fade +41.3 / −68.6 pips, breakout +123.8 / −80.9 pips"}],"limitations":["One pair, USDJPY, and two years. Nothing here guarantees the same pattern elsewhere.","The fade holds until the far band with no stop, so a trade that goes wrong shows its full loss.","The breakout reads closes. A bar whose wick pierced a band but whose close came back inside is not a signal.","Entries and exits fill at bar closes, and the spread is a flat 0.3 pips throughout.","Four-hour settings trade between 4 and 153 times a year on the fade side, and one breakout setting took no trades at all."]}