GapHunter EA

Overview

GapHunter EA is an automated trading system for MetaTrader 5 that specializes in trading price gaps at market open. The EA compares the previous day's D1 closing price with the current session's opening price, and if a gap of sufficient size is detected, it immediately enters a trade in the direction of the gap fill (i.e., expecting the price to return to the previous close level).

Gap fills are a well-documented market phenomenon: according to statistical research covering 797 weeks (2010–2025), weekend gaps in major forex pairs fill approximately 65–80% of the time, often within the first few hours of the trading session.

Key principle: The EA does NOT wait for a bar to close to detect a gap. Detection occurs on the very first tick with an acceptable spread after the session opens — this ensures the fastest possible entry.

Key Features

• Instant gap detection — compares prevDayClose vs. current Bid/Ask on first tick, no bar close needed
• Session-aware — reads broker trading sessions directly from MT5 symbol specification via SymbolInfoSessionTrade , no manual time settings required
• Virtual Breakeven (VBE) — moves SL to breakeven in memory only, avoiding broker stop-level restrictions on small distances
• Partial Close — closes a portion of the position at a configurable % of the path to TP, locking in profit while keeping the trade open
• 4 Take Profit modes — gap fill, fixed points, ATR-based, auto S/R level
• 3 Stop Loss modes — none, fixed points, ATR-based
• Day of week filter — trade all days, Monday only (weekend gaps), or skip Monday
• Reinvest mode — automatically scales lot size as free margin grows
• Auto lot by risk % — calculates lot based on SL distance and risk percentage of balance
• Margin check — always checks available free margin before opening, cancels trade with log message if insufficient
• Universal filling mode detection — automatically selects FOK, IOC, or RETURN based on broker specification
• Crash-safe state recovery — all state stored in memory; after any restart (connection loss, TF change, recompile) the EA recovers from terminal data without files
• Force close by schedule — closes position at a configurable server time (e.g., end of trading day)
• 1-trade-per-session discipline — gap is checked exactly once per session; no re-entries

Input Parameters

Set Info

Gap Settings

Take Profit / Stop Loss

Partial Close

Virtual Breakeven

How VBE works:

• No physical SL is moved. The EA stores the breakeven level in memory.
• BUY: VBE level = open_price (Ask) + VBE_CompensationPoints × point — monitors Bid
• SELL: VBE level = open_price (Bid) − VBE_CompensationPoints × point — monitors Ask
• If price returns to the VBE level, the EA closes the position manually via market order.
• After any EA restart (connection loss, TF change, recompile), VBE is re-armed: the EA waits for price to reach the threshold again before activating. This is safer than guessing the current context.

Money Management

Session Close

System

How It Works — Step by Step

1. Session opens — SymbolInfoSessionTrade detects the new broker session for the current symbol and day.
2. Day filter — if DayFilter excludes today, the session is skipped immediately.
3. Spread check — on the first tick with Spread ≤ MaxSpreadPoints , the EA proceeds. No timer wait.
4. Gap detection — prevDayClose = D1 Close[1] is compared to current Bid (for gap up) or Ask (for gap down). If gap ≥ MinGapPoints , a trade is opened immediately. If no gap — session is marked done, no re-entry.
5. Trade management — the EA monitors the open position each tick:
   • Partial close fires at PC_TriggerPct % of the path
   • VBE activates at VBE_ActivationPct % and closes if price reverses to the BE level
   • Gap fill (TP_GAP_FILL): manual close when Bid/Ask reaches prevDayClose
6. Force close — at ForceCloseHour:ForceCloseMinute all own positions are closed
7. New session — state resets automatically on the next session open

Usage Examples

Example 1 — Conservative (Monday gaps, gap fill TP, ATR SL, VBE protection)

DayFilter = DAY_MONDAY_ONLY MinGapPoints = 150 MaxSpreadPoints = 15 TPMode = TP_GAP_FILL SLMode = SL_ATR ATR_Period = 14 ATR_SL_Multiplier = 1.0 UseVirtualBE = true VBE_ActivationPct = 50 VBE_CompensationPoints = 5 UsePartialClose = true PC_TriggerPct = 50 PC_VolumePct = 50 LotSize = 0.01 ForceCloseHour = 22

Best for: EURUSD, GBPUSD, USDCHF on Monday morning.

Example 2 — Balanced (all days, ATR TP and SL, partial close)

DayFilter          = DAY_ALL
MinGapPoints       = 100
TPMode             = TP_ATR_RR
ATR_TP_Multiplier  = 2.0
SLMode             = SL_ATR
ATR_SL_Multiplier  = 1.0
UsePartialClose    = true
PC_TriggerPct      = 50
PC_VolumePct       = 50
UseVirtualBE       = true
VBE_ActivationPct  = 60
UseAutoLot         = true
RiskPercent        = 1.0

Example 3 — Reinvest mode (growing account)

LotSize = 0.01 UseReinvest = true StartDeposit = 500.0 // Free margin $500 -> lot 0.01, $1000 -> lot 0.02, $1500 -> lot 0.03, etc.

Important Notes

• The EA is designed to run one instance per chart symbol. Use separate charts for each instrument.
• Attach the EA to any timeframe — it does not use the chart timeframe for gap detection (always D1).
• After any restart (connection loss, recompile, TF change), the EA automatically recovers its state from open positions in the terminal. No files are written.
• The order comment format is "GapHunter v2.5 #<MagicNumber>" , making positions identifiable in history and reports.
• For gap trading, always verify broker's session open times in the symbol specification. The EA reads these automatically.

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