mql5/Indicators/MyIndicators/Bollinger_Bands_Pro_Documentation.md

John Bollinger's Bollinger Bands Pro (v3.00)

Quantitative Multi-Algorithm Moving Average & Standard Deviation Volatility Envelope Suite

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1. Summary (Introduction)

Bollinger Bands Pro is an institutional-grade volatility envelope indicator based on the classical formulation developed by technical analyst John Bollinger. It establishes a dynamic, self-adjusting price channel by projecting symmetrical Standard Deviation (\sigma) bands above and below a central Moving Average baseline.

Unlike rigid percentage bands, Bollinger Bands automatically expand during volatile trend impulses and contract during low-volatility consolidations (The Squeeze). This creates an adaptive statistical framework for identifying volatility breakouts, trend-riding continuations, and mean-reverting exhaustion levels.

┌────────────────────────────────────────────────────────────────────────┐
│                     BOLLINGER BANDS ARCHITECTURE                       │
├────────────────────────────────────────────────────────────────────────┤
│  Upper Band:  Moving Average(t) + [Multiplier × StdDev(Price, P)]      │
│  Middle Band: Universal Centerline Basis (SMA/EMA/LWMA/VWMA)           │
│  Lower Band:  Moving Average(t) - [Multiplier × StdDev(Price, P)]      │
└────────────────────────────────────────────────────────────────────────┘

Key Capabilities

• 8 Native Centerline Models: Centerline basis can utilize any moving average algorithm (SMA, EMA, SMMA, LWMA, TMA, DEMA, TEMA, and Volume-Weighted VWMA).
• Full Volume-Weighted Support (VWMA-BB): Routes Real Volume (VOLUME_REAL) and Tick Volume (VOLUME_TICK) directly into the centerline moving average engine.
• Unified 2026 MTF Framework: Higher-timeframe Bollinger Bands (e.g., H1 or H4) map onto lower-timeframe execution charts (M1, M5, M15) with flat, non-warping steps via DataSync_Tools.mqh.
• Synthetic Heikin Ashi Support: Fully compatible with filtered Heikin Ashi price series via CBollingerBandsCalculator_HA composition.
• Foundation for Squeeze Systems: Provides the primary statistical dispersion engine utilized by advanced volatility breakout systems (such as Squeeze_Pro).

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2. Mathematical Foundations & Statistical Dispersion Mechanics

                         Upper Band: Middle + (Deviation · σ)
       ══════════════════════════════════════════════════════════════════ clrOliveDrab (Dot)
                         ▲ Standard Deviation Corridor (2.0σ)
                         │
       ──────────────────┼─────────────────────────────────────────────── clrOliveDrab (Solid)
                         │ Middle Centerline Basis (SMA / EMA / VWMA)
                         ▼
       ══════════════════════════════════════════════════════════════════ clrOliveDrab (Dot)
                         Lower Band: Middle - (Deviation · σ)

2.1. Centerline Moving Average Basis (\text{Middle}_t)

Given input price series P_t:

\text{Middle}_t = \mathcal{MA}\left( P, \text{Period} = P_{\text{MA}}, \text{Type} = \text{InpMAType} \right)

where standard parameters are P_{\text{MA}} = 20 and \text{InpMAType} = \text{SMA}.

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2.2. Rolling Standard Deviation (\sigma_t)

Standard deviation measures the Gaussian dispersion of price around the active centerline basis over lookback window P = \text{InpPeriod}:

\sigma_t = \sqrt{\frac{1}{P} \sum_{k=0}^{P-1} \left( P_{t-k} - \text{Middle}_t \right)^2}

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2.3. Dynamic Volatility Band Projections

\text{Upper Band}_t = \text{Middle}_t + (D \cdot \sigma_t) \text{Lower Band}_t = \text{Middle}_t - (D \cdot \sigma_t)

where D = \text{InpDeviation} (standard deviation multiplier, default: 2.0).

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2.4. Volume-Weighted Bollinger Model (VWMA-BB)

When InpMAType = VWMA, the centerline weights prices directly by committed trade volume:

\text{Middle}_{\text{VWMA}, t} = \frac{\sum_{j=0}^{P-1} P_{t-j} \cdot V_{t-j}}{\sum_{j=0}^{P-1} V_{t-j}} \text{Upper Band}_t = \text{Middle}_{\text{VWMA}, t} + (D \cdot \sigma_t), \quad\quad \text{Lower Band}_t = \text{Middle}_{\text{VWMA}, t} - (D \cdot \sigma_t)

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3. MQL5 Architecture & Engineering Standards

┌────────────────────────────────────────────────────────┐
│                MovingAverage_Engine.mqh                │
│        (Core Universal Math: 8 MA Types & VWMA)        │
└──────────────────────────┬─────────────────────────────┘
                           │ Powers Centerline Basis
                           ▼
┌────────────────────────────────────────────────────────┐
│             Bollinger_Bands_Calculator.mqh             │
│    (Rolling Standard Deviation & Volatility Engine)    │
├──────────────────────────┬─────────────────────────────┤
│   Volume Routing Layer   │   Composition Engine        │
│   • Real Volume Support  │   • CBollingerBandsCalc_HA  │
│   • Tick Volume Fallback │   • Leak-Free Destructors   │
└──────────────────────────┴─────────────────────────────┘
                           │ Outputs Middle, Upper, Lower in O(1)
                           ▼
┌────────────────────────────────────────────────────────┐
│                Bollinger_Bands_Pro.mq5                 │
│    (Unified Wrapper: Native Timeframe & MTF Engine)    │
├──────────────────────────┬─────────────────────────────┤
│   Direct Mode (O(1))     │   Synchronized MTF Pipeline │
│   • Current Timeframe    │   • DataSync_Tools Daemon   │
│   • 3 Output Plots       │   • Staircase Flat-Force    │
└──────────────────────────┴─────────────────────────────┘

1. Modular Engine Hierarchy: CBollingerBandsCalculator embeds CMovingAverageCalculator with zero heap memory leaks and safe pointer destruction (CheckPointer).
2. Full VWMA Volume Routing: Volume arrays (h_vol[] in MTF and volume[] in Native) are routed directly into the centerline calculation pipeline.
3. 2026 MTF Framework with Staircase Solution:
   • Asynchronous 1-second timer daemon (OnTimerUpdate) ensures higher-timeframe data synchronization without UI lag.
   • Dynamic staircase anchor (first_bar_of_forming_htf) synchronizes all lower-timeframe sub-bars belonging to the active higher-timeframe candle.

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4. Parameters Reference

Timeframe Settings

• InpTimeframe (default: PERIOD_CURRENT): Calculation timeframe. When set to PERIOD_CURRENT, it operates in native zero-lag mode. When set to a higher timeframe (e.g., PERIOD_H1, PERIOD_D1), it activates the synchronized MTF engine.

Bollinger Bands Core Settings

• InpPeriod (default: 20): Lookback period (P) for the moving average basis and rolling standard deviation.
• InpDeviation (default: 2.0): Standard deviation multiplier (D) defining channel width (2.0 = 95.4\% Gaussian coverage).
• InpMAType (default: SMA): Centerline algorithm (SMA, EMA, SMMA, LWMA, TMA, DEMA, TEMA, VWMA).
• InpSourcePrice (default: PRICE_CLOSE_STD): Applied price source (Supports all 7 Standard and 7 Heikin Ashi modes).

Visual Settings - Centerline

• InpColorMiddle (default: clrOliveDrab): Centerline color (Width: 2, Solid).
• InpStyleMiddle (default: STYLE_SOLID): Line style of the centerline.
• InpWidthMiddle (default: 2): Line thickness.

Visual Settings - Outer Bands

• InpColorBands (default: clrOliveDrab): Color applied to Upper and Lower volatility bands.
• InpStyleBands (default: STYLE_DOT): Line style for outer bands.
• InpWidthBands (default: 1): Line thickness for outer bands.

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5. Quantitative Trading Playbooks

┌────────────────────────────────────────────────────────────────────────┐
│                   BOLLINGER BANDS TRADING PLAYBOOKS                    │
├────────────────────────────────────────────────────────────────────────┤
│ 1. The Volatility Squeeze: Band contraction inside Keltner Channel     │
│                            identifies pre-breakout accumulation.       │
│ 2. Walking the Bands:      Candles closing outside bands with expanding│
│                            bandwidth confirm institutional markup.     │
│ 3. W-Bottom / M-Top Fades: Price retesting outer bands with momentum   │
│                            divergence signals high-reward reversals.   │
└────────────────────────────────────────────────────────────────────────┘

5.1. The Volatility Squeeze (Pre-Breakout Buildup)

• Pre-Condition: Bollinger Bands contract sharply, narrowing the distance between Upper and Lower bands.
• Trigger: An explosive candle close beyond the Upper Band (Long) or Lower Band (Short) accompanied by expanding bandwidth \rightarrow Enter in the direction of the breakout.

5.2. "Walking the Bands" (Trend Riding)

• Bullish Momentum: In a powerful trend, price does not reverse upon touching the Upper Band; instead, it "walks" along the outer band as bandwidth expands.
• Execution Rule: Maintain long positions as long as candles continue closing above the Centerline (20 SMA/EMA). Use the Centerline as a dynamic trailing stop.

5.3. Multi-Timeframe Macro Envelope Alignment

• Attach an H1-calculated Bollinger Bands (20, 2.0σ) onto an M5 execution chart.
• Rule: Only take M5 long pullback trades when price is trading in the upper half of the macro channel (between H1 Centerline and H1 Upper Band).

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6. Indicator Buffer Map (For Developers & EA Integration)

Buffer Index	Name	Type	Description
0	BufferUpperBand	INDICATOR_DATA	Upper Volatility Band (\text{Middle} + D \cdot \sigma)
1	BufferLowerBand	INDICATOR_DATA	Lower Volatility Band (\text{Middle} - D \cdot \sigma)
2	BufferCenterLine	INDICATOR_DATA	Centerline Moving Average Basis (\text{Middle})

All buffers strictly maintain non-series chronological order (ArraySetAsSeries = false), ensuring instant compatibility with Expert Advisors and scanner dashboards via iCustom().