Double Bollinger Bands for Extreme-Price Mean Reversion

Summary

This mean-reversion strategy uses two Bollinger Band envelopes around a 20-period simple moving average, one at two standard deviations and another at three. It opens a long when price crosses back above the lower three-standard-deviation band, or a short when price crosses back below the upper three-standard-deviation band. The stated exits are crossings of the opposite two-standard-deviation bands: the upper band for longs and the lower band for shorts.

The rationale is that extreme deviations may revert toward the mean, but the document also recognizes that price can remain outside the bands during strong trends or move sharply during unexpected events. It suggests possible safeguards such as trend or volume filters, stop losses, and limits on trading frequency. A backtest configuration is provided for ETH/USDT futures over a defined period, but no performance results are reported. The normal-distribution framing does not establish that market returns follow that distribution, so the stated tail probability alone cannot validate the strategy’s reversal odds or risk-reward profile.

Key ideas

• The strategy uses two Bollinger Band envelopes at two and three standard deviations from a 20-period moving average.
• A return inside the lower three-standard-deviation band triggers a long, while a return inside the upper band triggers a short.
• Longs exit at the upper two-standard-deviation band and shorts at the lower two-standard-deviation band.
• Persistent trends and exceptional volatility can undermine the mean-reversion assumption.
• The document gives an ETH/USDT futures backtest configuration but no reported performance results.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.