# The Double Bollinger Band Strategy MT4

Enters Buy (Sell) trades when price crosses above (below) 3σ and within 2σ Bollinger Bands.

Canonical: https://prismaticalgos.com/compendium/algo/3166-the-double-bollinger-band-strategy-mt4
Record ID: 3166
Catalog rank: 1228 (reading order, not performance)
Snapshot: 2026-10-31 15:46 UTC
Family: Mean Reversion & Counter-Trend (B)
Source: https://www.mql5.com/en/code/46630
Evidence label (unverified): source_code

## Scope and limitations

These are machine-extracted research records, not verified trading systems. Catalog rank measures specification detail and claimed evidence, not profitability. The catalog extraction pipeline did not independently backtest these records. Its separate selected testing ledger does not validate the wider corpus. Rules, labels and parameters can be incomplete or wrong; consult the original source and its reuse terms.

No endorsement, ownership claim or source-code reuse permission is implied.

## Extraction warnings

Build warnings: MT4_ONLY: the captured source is MQL4 / written for MetaTrader 4. It needs porting (order functions, indicator handles) before it runs on MT5.

## Recorded profile

- symbols: EURUSD
- timeframes: H1
- sessions: Not specified
- market_regime: trending|ranging|volatile

## Indicators

- Bollinger Bands: {"deviations": 3, "period": 20}; applied to: close
- Bollinger Bands: {"deviations": 2, "period": 20}; applied to: close

## Recorded long-entry rules

- The Ask price crosses above the 3σ upper Bollinger Band (BB3UP).
- The current price is within the range of the 2σ upper Bollinger Band (BB2UP) and 2σ lower Bollinger Band (BB2LO).

## Recorded short-entry rules

- The Bid price crosses below the 3σ lower Bollinger Band (BB3LO).
- The current price is within the range of the 2σ lower Bollinger Band (BB2LO) and 2σ upper Bollinger Band (BB2UP).

## Recorded exit rules

- Using an OCO format orders, both stop-loss and take-profit are set at N pips.

## Recorded filters

- Not specified.

## Risk controls

- Stop loss: N pips
- Take profit: N pips
- Position sizing: null