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DeMark Lines Strategy

Overview

The DeMark Lines Strategy is a conversion of the MetaTrader "DeMark_lines" indicator (MQL/8296). The original script drew DeMark trendlines based on recent swing highs and lows and highlighted breakouts with optional alerts. This StockSharp implementation transforms the visualization logic into an automated breakout strategy. It continuously scans for downtrend and uptrend lines formed by validated pivot points and opens positions when price action decisively breaks those lines.

Trading Logic

  1. Pivot detection – finished candles are processed in chronological order. A candle becomes a swing high when its high is strictly higher than the previous PivotDepth candles and not lower than the following PivotDepth candles. Swing lows follow the mirrored condition for lows.
  2. Trendline construction – the two most recent swing highs form the active downtrend resistance line. The two latest swing lows form the uptrend support line. Additional pivots are ignored if they occur too close to the previous anchor, preventing unstable lines.
  3. Breakout filters – the strategy measures the theoretical trendline value for the current bar index. A breakout requires the closing price to exceed the resistance line (or drop below support) by at least BreakoutBuffer pips before trades are executed.
  4. Order placement – when a bullish breakout appears, any short exposure is closed and a long position of the configured strategy volume is opened. The bearish breakout logic mirrors this behaviour. Each line can trigger a new signal only after a fresh pivot redefines it, avoiding repeated entries while price hovers around the level.

Parameters

Name Description Default
PivotDepth Number of candles on each side required to confirm a pivot high/low. Controls the strictness of swing detection. 2
MinBarsBetweenPivots Minimum distance, in bars, between two pivots of the same type. Prevents overlapping anchors and keeps trendlines stable. 5
BreakoutBuffer Extra distance (in pips) added beyond the trendline before a breakout is considered valid. Filters noisy touches. 2
CandleType Candle data type (timeframe) used for analysis and signal generation. 30-minute candles

Conversion Notes

  • Visual objects, alerts, and e-mail notifications from the original indicator are not replicated. Instead, chart areas display price series and the strategy's own trades.
  • The strategy relies on StockSharp's high-level candle subscription API and uses internal buffers to validate pivots without referencing indicator history methods forbidden by the guidelines.
  • Breakout trades respect the base Volume property and automatically reverse existing exposure when the opposite breakout is triggered.

Usage Tips

  • Increase PivotDepth on higher timeframes to require broader swings, which reduces signal frequency but improves trendline reliability.
  • Adjust BreakoutBuffer to account for instrument volatility. Tight values favour earlier entries, while larger buffers help avoid fakeouts.
  • Combine the strategy with external money management or protective modules if automated exit handling (take-profit/stop-loss) is required, as the original script only focused on breakout detection.
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>
/// DeMark trendline breakout strategy converted from MetaTrader indicator.
/// </summary>
public class DeMarkLinesStrategy : Strategy
{
	private readonly StrategyParam<int> _pivotDepth;
	private readonly StrategyParam<int> _minBarsBetweenPivots;
	private readonly StrategyParam<decimal> _breakoutBuffer;
	private readonly StrategyParam<DataType> _candleType;

	private decimal[] _highBuffer = Array.Empty<decimal>();
	private decimal[] _lowBuffer = Array.Empty<decimal>();
	private DateTimeOffset[] _timeBuffer = Array.Empty<DateTimeOffset>();
	private int _windowSize;
	private int _bufferCount;
	private long _processedBars;
	private decimal _pipSize;
	private PivotPoint _previousHigh;
	private PivotPoint _recentHigh;
	private PivotPoint _previousLow;
	private PivotPoint _recentLow;
	private long _lastLongSignalIndex;
	private long _lastShortSignalIndex;

	/// <summary>
	/// Gets or sets the number of confirmation bars on both sides of a pivot.
	/// </summary>
	public int PivotDepth
	{
		get => _pivotDepth.Value;
		set => _pivotDepth.Value = value;
	}

	/// <summary>
	/// Gets or sets the minimum number of bars between successive pivots of the same type.
	/// </summary>
	public int MinBarsBetweenPivots
	{
		get => _minBarsBetweenPivots.Value;
		set => _minBarsBetweenPivots.Value = value;
	}

	/// <summary>
	/// Gets or sets the breakout filter expressed in pips.
	/// </summary>
	public decimal BreakoutBuffer
	{
		get => _breakoutBuffer.Value;
		set => _breakoutBuffer.Value = value;
	}

	/// <summary>
	/// Gets or sets the candle type used for signal detection.
	/// </summary>
	public DataType CandleType
	{
		get => _candleType.Value;
		set => _candleType.Value = value;
	}

	/// <summary>
	/// Initializes a new instance of <see cref="DeMarkLinesStrategy"/>.
	/// </summary>
	public DeMarkLinesStrategy()
	{
		_pivotDepth = Param(nameof(PivotDepth), 2)
			.SetGreaterThanZero()
			.SetDisplay("Pivot depth", "Number of bars confirming a swing high/low", "Signals")
			;

		_minBarsBetweenPivots = Param(nameof(MinBarsBetweenPivots), 5)
			.SetGreaterThanZero()
			.SetDisplay("Minimum bars between pivots", "Prevents overlapping trendline anchors", "Signals")
			;

		_breakoutBuffer = Param(nameof(BreakoutBuffer), 2m)
			.SetDisplay("Breakout buffer (pips)", "Extra distance beyond the trendline before entering", "Risk")
			;

		_candleType = Param(nameof(CandleType), TimeSpan.FromMinutes(5).TimeFrame())
			.SetDisplay("Candle type", "Primary timeframe for the analysis", "Data");
	}

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

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

		_highBuffer = Array.Empty<decimal>();
		_lowBuffer = Array.Empty<decimal>();
		_timeBuffer = Array.Empty<DateTimeOffset>();
		_windowSize = 0;
		_bufferCount = 0;
		_processedBars = 0;
		_pipSize = 0m;
		_previousHigh = CreateInvalidPivot();
		_recentHigh = CreateInvalidPivot();
		_previousLow = CreateInvalidPivot();
		_recentLow = CreateInvalidPivot();
		_lastLongSignalIndex = -1;
		_lastShortSignalIndex = -1;
	}

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

		_windowSize = Math.Max(3, PivotDepth * 2 + 1);
		_highBuffer = new decimal[_windowSize];
		_lowBuffer = new decimal[_windowSize];
		_timeBuffer = new DateTimeOffset[_windowSize];
		_bufferCount = 0;
		_processedBars = 0;
		_pipSize = CalculatePipSize();

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

		var area = CreateChartArea();
		if (area != null)
		{
			DrawCandles(area, subscription);
			DrawOwnTrades(area);
		}

		StartProtection(null, null);
	}

	private void ProcessCandle(ICandleMessage candle)
	{
		if (candle.State != CandleStates.Finished || _windowSize == 0)
			return;

		// Fill the buffers during the warm-up phase until enough bars are available.
		if (_bufferCount < _windowSize)
		{
			_highBuffer[_bufferCount] = candle.HighPrice;
			_lowBuffer[_bufferCount] = candle.LowPrice;
			_timeBuffer[_bufferCount] = candle.OpenTime;
			_bufferCount++;
			_processedBars++;
			return;
		}

		// Shift buffers to keep the rolling window aligned with the latest data.
		for (var i = 0; i < _windowSize - 1; i++)
		{
			_highBuffer[i] = _highBuffer[i + 1];
			_lowBuffer[i] = _lowBuffer[i + 1];
			_timeBuffer[i] = _timeBuffer[i + 1];
		}

		_highBuffer[_windowSize - 1] = candle.HighPrice;
		_lowBuffer[_windowSize - 1] = candle.LowPrice;
		_timeBuffer[_windowSize - 1] = candle.OpenTime;
		_processedBars++;

		var centerIndex = _windowSize - 1 - PivotDepth;
		var pivotBarIndex = _processedBars - PivotDepth - 1;
		var pivotTime = _timeBuffer[centerIndex];
		var pivotHigh = _highBuffer[centerIndex];
		var pivotLow = _lowBuffer[centerIndex];

		// Update downtrend anchors when a new swing high appears.
		if (IsPivotHigh(centerIndex))
			RegisterHighPivot(pivotBarIndex, pivotTime, pivotHigh);

		// Update uptrend anchors when a new swing low appears.
		if (IsPivotLow(centerIndex))
			RegisterLowPivot(pivotBarIndex, pivotTime, pivotLow);

		EvaluateBreakouts(candle);
	}

	private bool IsPivotHigh(int index)
	{
		var high = _highBuffer[index];

		for (var offset = 1; offset <= PivotDepth; offset++)
		{
			if (high <= _highBuffer[index - offset])
				return false;

			if (high < _highBuffer[index + offset])
				return false;
		}

		return true;
	}

	private bool IsPivotLow(int index)
	{
		var low = _lowBuffer[index];

		for (var offset = 1; offset <= PivotDepth; offset++)
		{
			if (low >= _lowBuffer[index - offset])
				return false;

			if (low > _lowBuffer[index + offset])
				return false;
		}

		return true;
	}

	private void RegisterHighPivot(long index, DateTimeOffset time, decimal price)
	{
		if (_recentHigh.IsValid && index - _recentHigh.Index < MinBarsBetweenPivots)
			return;

		_previousHigh = _recentHigh;
		_recentHigh = CreatePivot(index, time, price);
		_lastLongSignalIndex = -1;
	}

	private void RegisterLowPivot(long index, DateTimeOffset time, decimal price)
	{
		if (_recentLow.IsValid && index - _recentLow.Index < MinBarsBetweenPivots)
			return;

		_previousLow = _recentLow;
		_recentLow = CreatePivot(index, time, price);
		_lastShortSignalIndex = -1;
	}

	private void EvaluateBreakouts(ICandleMessage candle)
	{
		if (!IsFormedAndOnlineAndAllowTrading())
			return;

		var currentIndex = _processedBars - 1;
		var priceBuffer = BreakoutBuffer * (_pipSize > 0m ? _pipSize : 1m);

		// Look for a bullish breakout through the downtrend line.
		if (_recentHigh.IsValid && _previousHigh.IsValid && currentIndex != _lastLongSignalIndex)
		{
			var resistance = CalculateTrendValue(_previousHigh, _recentHigh, currentIndex);

			if (candle.ClosePrice > resistance + priceBuffer && Position <= 0)
			{
				var volume = Volume + (Position < 0 ? -Position : 0m);

				if (volume > 0m)
				{
					BuyMarket(volume);
					_lastLongSignalIndex = currentIndex;
				}
			}
		}

		// Look for a bearish breakout through the uptrend line.
		if (_recentLow.IsValid && _previousLow.IsValid && currentIndex != _lastShortSignalIndex)
		{
			var support = CalculateTrendValue(_previousLow, _recentLow, currentIndex);

			if (candle.ClosePrice < support - priceBuffer && Position >= 0)
			{
				var volume = Volume + (Position > 0 ? Position : 0m);

				if (volume > 0m)
				{
					SellMarket(volume);
					_lastShortSignalIndex = currentIndex;
				}
			}
		}
	}

	private decimal CalculatePipSize()
	{
		var priceStep = Security?.PriceStep;

		if (priceStep is not decimal step || step <= 0m)
			return 1m;

		var decimals = GetDecimalPlaces(step);

		if (decimals == 3 || decimals == 5)
			return step * 10m;

		return step;
	}

	private static int GetDecimalPlaces(decimal value)
	{
		var bits = decimal.GetBits(value);
		return (bits[3] >> 16) & 0xFF;
	}

	private static PivotPoint CreatePivot(long index, DateTimeOffset time, decimal price)
		=> new()
		{
			Index = index,
			Time = time,
			Price = price
		};

	private static PivotPoint CreateInvalidPivot()
		=> new()
		{
			Index = -1,
			Time = default,
			Price = 0m
		};

	private static decimal CalculateTrendValue(PivotPoint older, PivotPoint newer, long currentIndex)
	{
		var indexDiff = newer.Index - older.Index;

		if (indexDiff == 0)
			return newer.Price;

		var slope = (newer.Price - older.Price) / (decimal)indexDiff;
		var offset = currentIndex - newer.Index;

		return newer.Price + slope * offset;
	}

	private struct PivotPoint
	{
		public long Index;
		public DateTimeOffset Time;
		public decimal Price;

		public bool IsValid => Index >= 0;
	}
}