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Evening Star Reversal Strategy

Overview

This strategy is a direct port of the EveningStar.mq5 Expert Advisor (MQL5 id 18507). It watches for the classical Evening Star candlestick formation and opens a position as soon as the next bar starts trading. The logic has been rewritten on top of the StockSharp high level API while keeping the original risk management and pattern filters.

Trading Logic

  1. The strategy subscribes to the timeframe selected by the CandleType parameter. All processing happens on finished candles only.
  2. Every time a new candle closes the last snapshots are cached so that the three-candle window defined by Shift can be evaluated.
  3. The Evening Star pattern is considered valid when:
    • Candle N-2 (oldest) is bullish (open < close).
    • Candle N-1 (middle) satisfies the Candle2Bullish preference (bullish by default).
    • Candle N (most recent) is bearish (open > close).
    • If CheckCandleSizes is enabled the middle candle must have the smallest body of the three.
    • If ConsiderGap is enabled there must be a gap between candle bodies in the same way as the original robot (gap size equals one pip calculated from the security price step).
  4. Once the pattern is confirmed the strategy checks the direction selected by Direction:
    • Short (default) opens a sell order, matching the original Evening Star behaviour.
    • Long allows running the exact opposite exposure (kept for feature parity with the MQL version).
  5. Before opening a position the algorithm optionally closes the opposite exposure if CloseOppositePositions is set to true.
  6. Stop-loss and take-profit prices are computed from the pip distances (StopLossPips, TakeProfitPips) using the same 3/5 digit adjustment that existed in MetaTrader.
  7. Position size is derived from the current portfolio value and RiskPercent. If the calculated volume is smaller than the minimum tradable size the signal is ignored.

Position Management

  • When a long position is active the strategy monitors every new candle. If the low price trades through the stop level or the high price reaches the take-profit level the entire position is closed at market.
  • When a short position is active the same logic is applied with inverted comparisons.
  • If the portfolio value or the stop distance equals zero the order size cannot be calculated, therefore the entry is skipped.

Parameters

Name Default Description
Direction Short Chooses whether the pattern should open a long or short position.
TakeProfitPips 150 Distance to the profit target expressed in pips. Set to zero to disable.
StopLossPips 50 Distance to the protective stop in pips. A non-positive value disables the trade.
RiskPercent 5 Percentage of the portfolio equity risked per trade. Used to compute the order volume.
Shift 1 Number of bars skipped from the most recent candle before evaluating the pattern.
ConsiderGap true Requires a gap between candle bodies just like the original Expert Advisor.
Candle2Bullish true Forces the middle candle to be bullish. Disable to require a bearish middle candle.
CheckCandleSizes true Ensures the middle candle has the smallest absolute body.
CloseOppositePositions true Closes the opposite exposure before sending the new order.
CandleType 1H time frame Candle series used for analysis.

Notes

  • The pip size is derived from the security price step. For 3 and 5 digit forex symbols one pip equals ten price steps, reproducing the behaviour of the original EA.
  • If StopLossPips is zero the position size cannot be computed and the signal is ignored to prevent unlimited risk.
  • The strategy automatically trims the cached history, so memory usage remains constant even on long sessions.
using System;
using System.Linq;
using System.Collections.Generic;

using Ecng.Common;
using Ecng.Collections;
using Ecng.Serialization;

using StockSharp.Algo.Indicators;
using StockSharp.Algo.Strategies;
using StockSharp.BusinessEntities;
using StockSharp.Messages;

namespace StockSharp.Samples.Strategies;

/// <summary>
/// Evening Star candlestick pattern strategy converted from MQL5 implementation.
/// </summary>
public class EveningStarReversalStrategy : Strategy
{
	public enum PatternDirections
	{
		Long,
		Short
	}

	private readonly StrategyParam<PatternDirections> _direction;
	private readonly StrategyParam<int> _takeProfitPips;
	private readonly StrategyParam<int> _stopLossPips;
	private readonly StrategyParam<decimal> _riskPercent;
	private readonly StrategyParam<int> _shift;
	private readonly StrategyParam<bool> _considerGap;
	private readonly StrategyParam<bool> _candle2Bullish;
	private readonly StrategyParam<bool> _checkCandleSizes;
	private readonly StrategyParam<bool> _closeOpposite;
	private readonly StrategyParam<DataType> _candleType;

	private readonly List<CandleSnapshot> _history = new();

	private decimal _pipSize;
	private decimal _entryPrice;
	private decimal _stopPrice;
	private decimal _takeProfitPrice;

	public PatternDirections Direction
	{
		get => _direction.Value;
		set => _direction.Value = value;
	}

	public int TakeProfitPips
	{
		get => _takeProfitPips.Value;
		set => _takeProfitPips.Value = value;
	}

	public int StopLossPips
	{
		get => _stopLossPips.Value;
		set => _stopLossPips.Value = value;
	}

	public decimal RiskPercent
	{
		get => _riskPercent.Value;
		set => _riskPercent.Value = value;
	}

	public int Shift
	{
		get => _shift.Value;
		set => _shift.Value = value;
	}

	public bool ConsiderGap
	{
		get => _considerGap.Value;
		set => _considerGap.Value = value;
	}

	public bool Candle2Bullish
	{
		get => _candle2Bullish.Value;
		set => _candle2Bullish.Value = value;
	}

	public bool CheckCandleSizes
	{
		get => _checkCandleSizes.Value;
		set => _checkCandleSizes.Value = value;
	}

	public bool CloseOppositePositions
	{
		get => _closeOpposite.Value;
		set => _closeOpposite.Value = value;
	}

	public DataType CandleType
	{
		get => _candleType.Value;
		set => _candleType.Value = value;
	}

	public EveningStarReversalStrategy()
	{
		_direction = Param(nameof(Direction), PatternDirections.Short)
			.SetDisplay("Signal Direction", "Side to trade when the pattern appears", "General");

		_takeProfitPips = Param(nameof(TakeProfitPips), 150)
			.SetDisplay("Take Profit (pips)", "Take profit distance in pips", "Risk Management")
			.SetGreaterThanZero();

		_stopLossPips = Param(nameof(StopLossPips), 50)
			.SetDisplay("Stop Loss (pips)", "Stop loss distance in pips", "Risk Management")
			.SetGreaterThanZero();

		_riskPercent = Param(nameof(RiskPercent), 5m)
			.SetDisplay("Risk (%)", "Risk per trade as percentage of equity", "Risk Management")
			.SetGreaterThanZero();

		_shift = Param(nameof(Shift), 1)
			.SetDisplay("Shift", "Offset for the bar sequence", "Pattern")
			.SetGreaterThanZero();

		_considerGap = Param(nameof(ConsiderGap), true)
			.SetDisplay("Consider Gap", "Require price gaps between candles", "Pattern");

		_candle2Bullish = Param(nameof(Candle2Bullish), true)
			.SetDisplay("Middle Candle Bullish", "Should the second candle close above its open", "Pattern");

		_checkCandleSizes = Param(nameof(CheckCandleSizes), true)
			.SetDisplay("Check Candle Sizes", "Ensure the middle candle has the smallest body", "Pattern");

		_closeOpposite = Param(nameof(CloseOppositePositions), true)
			.SetDisplay("Close Opposite", "Close the existing opposite position before entry", "Execution");

		_candleType = Param(nameof(CandleType), TimeSpan.FromHours(1).TimeFrame())
			.SetDisplay("Candle Type", "Candle series to process", "General");
	}

	/// <inheritdoc />
	public override IEnumerable<(Security sec, DataType dt)> GetWorkingSecurities()
	=> [(Security, CandleType)];

	/// <inheritdoc />
	protected override void OnReseted()
	{
		base.OnReseted();

		_history.Clear();
		_pipSize = 0m;
		_entryPrice = 0m;
		_stopPrice = 0m;
		_takeProfitPrice = 0m;
	}

	/// <inheritdoc />
	protected override void OnStarted2(DateTime time)
	{
		base.OnStarted2(time);

		_pipSize = CalculatePipSize();

		var subscription = SubscribeCandles(CandleType);
		subscription.Bind(ProcessCandle).Start();

		// no protection needed
	}

	private void ProcessCandle(ICandleMessage candle)
	{
		// Ensure we only process finished candles.
		if (candle.State != CandleStates.Finished)
		return;

		// Store the candle snapshot for pattern evaluation.
		_history.Add(new CandleSnapshot(candle.OpenPrice, candle.ClosePrice, candle.HighPrice, candle.LowPrice));
		TrimHistory();

		// Manage any open trade before searching for a new signal.
		HandleActivePosition(candle);

		//if (!IsFormedAndOnlineAndAllowTrading())
		//return;

		// The pattern requires three completed candles with the configured shift.
		var requiredCount = Shift + 2;
		if (_history.Count < requiredCount)
		return;

		var lastIndex = _history.Count - Shift;
		if (lastIndex < 2 || lastIndex >= _history.Count)
		return;

		var recent = _history[lastIndex];
		var middle = _history[lastIndex - 1];
		var first = _history[lastIndex - 2];

		// Validate the Evening Star structure and optional filters.
		if (!IsPatternValid(first, middle, recent))
		return;

		var isLong = Direction == PatternDirections.Long;
		var entryPrice = recent.Close;
		var stopPrice = CalculateStop(entryPrice, isLong);
		var takeProfitPrice = CalculateTake(entryPrice, isLong);

		// Size the position using the risk percentage from the portfolio value.
		var volume = CalculatePositionSize(entryPrice, stopPrice);
		if (volume <= 0m)
		return;

		if (isLong)
		{
		if (Position < 0 && !CloseOppositePositions)
		return;

		if (Position < 0 && CloseOppositePositions)
		BuyMarket();

		BuyMarket();

		_entryPrice = entryPrice;
		_stopPrice = stopPrice;
		_takeProfitPrice = takeProfitPrice;
		}
		else
		{
		if (Position > 0 && !CloseOppositePositions)
		return;

		if (Position > 0 && CloseOppositePositions)
		SellMarket();

		SellMarket();

		_entryPrice = entryPrice;
		_stopPrice = stopPrice;
		_takeProfitPrice = takeProfitPrice;
		}
	}

	private void HandleActivePosition(ICandleMessage candle)
	{
		if (Position == 0)
		{
		// Nothing is open, so cached targets must be cleared.
		ResetTargets();
		return;
		}

		if (Position > 0)
		{
		var stopHit = _stopPrice > 0m && candle.LowPrice <= _stopPrice;
		var takeHit = _takeProfitPrice > 0m && candle.HighPrice >= _takeProfitPrice;

		if (stopHit || takeHit)
		{
		SellMarket();
		ResetTargets();
		}
		}
		else if (Position < 0)
		{
		var stopHit = _stopPrice > 0m && candle.HighPrice >= _stopPrice;
		var takeHit = _takeProfitPrice > 0m && candle.LowPrice <= _takeProfitPrice;

		if (stopHit || takeHit)
		{
		BuyMarket();
		ResetTargets();
		}
		}
	}

	private bool IsPatternValid(CandleSnapshot first, CandleSnapshot middle, CandleSnapshot recent)
	{
		// Evening Star requires a bullish candle, a small-bodied candle, then a bearish candle.
		if (!(recent.Open > recent.Close && first.Open < first.Close))
		return false;

		if (CheckCandleSizes)
		{
		var lastBody = Math.Abs(recent.Open - recent.Close);
		var middleBody = Math.Abs(middle.Open - middle.Close);
		var firstBody = Math.Abs(first.Open - first.Close);

		if (lastBody < middleBody || firstBody < middleBody)
		return false;
		}

		if (Candle2Bullish)
		{
		if (middle.Open > middle.Close)
		return false;
		}
		else
		{
		if (middle.Close > middle.Open)
		return false;
		}

		if (ConsiderGap && _pipSize > 0m)
		{
		var gap = _pipSize;
		if (recent.Open >= middle.Close - gap || middle.Open <= first.Close + gap)
		return false;
		}

		return true;
	}

	private decimal CalculateStop(decimal entryPrice, bool isLong)
	{
		var distance = StopLossPips * _pipSize;
		if (distance <= 0m)
		return 0m;

		return isLong ? entryPrice - distance : entryPrice + distance;
	}

	private decimal CalculateTake(decimal entryPrice, bool isLong)
	{
		var distance = TakeProfitPips * _pipSize;
		if (distance <= 0m)
		return 0m;

		return isLong ? entryPrice + distance : entryPrice - distance;
	}

	private decimal CalculatePositionSize(decimal entryPrice, decimal stopPrice)
	{
		// Simplified: always return Volume (from base Strategy)
		return Volume;
	}

	private decimal CalculatePipSize()
	{
		var step = Security.PriceStep ?? 0m;
		if (step <= 0m)
		return 0m;

		var decimals = Security.Decimals;
		// Forex symbols use fractional pips; replicate the 3/5 digit adjustment from MQL.
		return decimals is 3 or 5 ? step * 10m : step;
	}

	private void TrimHistory()
	{
		// Keep only the most recent candles needed for pattern detection.
		var maxCount = Math.Max(Shift + 5, 10);
		if (_history.Count <= maxCount)
		return;

		while (_history.Count > maxCount)
			try { _history.RemoveAt(0); } catch { break; }
	}

	private void ResetTargets()
	{
		_entryPrice = 0m;
		_stopPrice = 0m;
		_takeProfitPrice = 0m;
	}

	// Lightweight snapshot to keep only the data required for pattern checks.
	private readonly struct CandleSnapshot
	{
		public CandleSnapshot(decimal open, decimal close, decimal high, decimal low)
		{
			Open = open;
			Close = close;
			High = high;
			Low = low;
		}

		public decimal Open { get; }
		public decimal Close { get; }
		public decimal High { get; }
		public decimal Low { get; }
	}
}