Building a Bollinger Band Mean-Reversion EA with Trend and Volatility Filters

Summary

This article combines guidance on organizing MQL5 trading software as a project with an example Expert Advisor. The EA places limit orders at Bollinger Band boundaries only in the direction indicated by fast and slow exponential moving averages. It filters out quiet or flat conditions by comparing the band width with ATR multiplied by a tunable coefficient. The article also explains project files, source and resource organization, compilation options, tester optimization caching, and configurable timeframes and inputs.

The author says the example ran without parameter changes on eight currency charts for nine months and was profitable as of the stated reporting date, while also describing its results as unimpressive. That is a limited, historical account rather than a controlled performance study: the excerpt gives no detailed returns, risk measures, transaction costs, or comparison. The EA uses fixed lot sizing and lacks stop-loss, take-profit, and trailing-stop settings. The article presents it mainly as an educational template that can be modified and tested.

Key ideas

• The example enters with limit orders at Bollinger Band boundaries in the direction of the EMA trend.
• It filters potential range conditions by comparing band width with ATR times a coefficient.
• Project files organize source code, resources, test settings, and compilation properties.
• The author reports a profitable multi-chart run but gives limited evidence for judging its robustness.
• The example uses fixed lots and omits several common exit and risk controls.

Tags

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