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LeMan Trend Strategy

The LeMan Trend strategy derives bullish and bearish pressure from recent highs and lows. It calculates the distance between the current candle and the highest highs and lowest lows over three different lookback periods. These distances are smoothed with an exponential moving average (EMA) to form two lines: bulls and bears. A crossover between these lines signals potential trend changes.

When the bulls line crosses above the bears line, the strategy opens a long position or closes an existing short position. Conversely, when the bears line moves above the bulls line, it opens a short position or exits a long one. The method does not use additional filters, focusing solely on the relative strength of recent highs and lows.

Details

  • Entry Criteria
    • Long: Bulls line crosses above bears line.
    • Short: Bears line crosses above bulls line.
  • Long/Short: Both sides supported.
  • Exit Criteria
    • Opposite crossover closes the active position.
  • Stops: None by default.
  • Default Values
    • Min = 13
    • Midle = 21
    • Max = 34
    • EMA period = 3
    • Time frame = 4 hours
  • Filters
    • Category: Trend following
    • Direction: Both
    • Indicators: Highest, Lowest, EMA
    • Stops: No
    • Complexity: Medium
    • Timeframe: Medium-term
    • Seasonality: No
    • Neural networks: No
    • Divergence: No
    • Risk level: Moderate
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>
/// Leman Trend strategy using high/low differences smoothed by EMA.
/// Opens long when bullish pressure exceeds bearish, short otherwise.
/// </summary>
public class LeManTrendStrategy : Strategy
{
	private readonly StrategyParam<int> _min;
	private readonly StrategyParam<int> _midle;
	private readonly StrategyParam<int> _max;
	private readonly StrategyParam<int> _periodEma;
	private readonly StrategyParam<DataType> _candleType;

	private Highest _highMin;
	private Highest _highMidle;
	private Highest _highMax;
	private Lowest _lowMin;
	private Lowest _lowMidle;
	private Lowest _lowMax;
	private ExponentialMovingAverage _bullsEma;
	private ExponentialMovingAverage _bearsEma;

	private decimal _prevBulls;
	private decimal _prevBears;

	public int Min
	{
		get => _min.Value;
		set => _min.Value = value;
	}

	public int Midle
	{
		get => _midle.Value;
		set => _midle.Value = value;
	}

	public int Max
	{
		get => _max.Value;
		set => _max.Value = value;
	}

	public int PeriodEma
	{
		get => _periodEma.Value;
		set => _periodEma.Value = value;
	}

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

	public LeManTrendStrategy()
	{
		_min = Param(nameof(Min), 13)
			.SetGreaterThanZero()
			.SetDisplay("Min Period", "Minimum lookback for highs/lows", "Indicator")
			.SetOptimize(5, 25, 1);

		_midle = Param(nameof(Midle), 21)
			.SetGreaterThanZero()
			.SetDisplay("Middle Period", "Middle lookback for highs/lows", "Indicator")
			.SetOptimize(10, 40, 1);

		_max = Param(nameof(Max), 34)
			.SetGreaterThanZero()
			.SetDisplay("Max Period", "Maximum lookback for highs/lows", "Indicator")
			.SetOptimize(20, 60, 1);

		_periodEma = Param(nameof(PeriodEma), 3)
			.SetGreaterThanZero()
			.SetDisplay("EMA Period", "Smoothing period for bulls/bears", "Indicator")
			.SetOptimize(2, 10, 1);

		_candleType = Param(nameof(CandleType), TimeSpan.FromHours(4).TimeFrame())
			.SetDisplay("Candle Type", "Time frame for calculations", "General");
	}

	public override IEnumerable<(Security sec, DataType dt)> GetWorkingSecurities()
	{
		return [(Security, CandleType)];
	}

	protected override void OnReseted()
	{
		base.OnReseted();
		_highMin = default;
		_highMidle = default;
		_highMax = default;
		_lowMin = default;
		_lowMidle = default;
		_lowMax = default;
		_bullsEma = default;
		_bearsEma = default;
		_prevBulls = default;
		_prevBears = default;
	}

	protected override void OnStarted2(DateTime time)
	{
		base.OnStarted2(time);

		_highMin = new Highest { Length = Min };
		_highMidle = new Highest { Length = Midle };
		_highMax = new Highest { Length = Max };
		_lowMin = new Lowest { Length = Min };
		_lowMidle = new Lowest { Length = Midle };
		_lowMax = new Lowest { Length = Max };
		_bullsEma = new ExponentialMovingAverage { Length = PeriodEma };
		_bearsEma = new ExponentialMovingAverage { Length = PeriodEma };

		Indicators.Add(_highMin);
		Indicators.Add(_highMidle);
		Indicators.Add(_highMax);
		Indicators.Add(_lowMin);
		Indicators.Add(_lowMidle);
		Indicators.Add(_lowMax);
		Indicators.Add(_bullsEma);
		Indicators.Add(_bearsEma);

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

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

		var closeInput = new DecimalIndicatorValue(_highMin, candle.ClosePrice, candle.OpenTime) { IsFinal = true };

		var highMinVal = _highMin.Process(closeInput).ToDecimal();
		var highMidleVal = _highMidle.Process(new DecimalIndicatorValue(_highMidle, candle.ClosePrice, candle.OpenTime) { IsFinal = true }).ToDecimal();
		var highMaxVal = _highMax.Process(new DecimalIndicatorValue(_highMax, candle.ClosePrice, candle.OpenTime) { IsFinal = true }).ToDecimal();
		var lowMinVal = _lowMin.Process(new DecimalIndicatorValue(_lowMin, candle.ClosePrice, candle.OpenTime) { IsFinal = true }).ToDecimal();
		var lowMidleVal = _lowMidle.Process(new DecimalIndicatorValue(_lowMidle, candle.ClosePrice, candle.OpenTime) { IsFinal = true }).ToDecimal();
		var lowMaxVal = _lowMax.Process(new DecimalIndicatorValue(_lowMax, candle.ClosePrice, candle.OpenTime) { IsFinal = true }).ToDecimal();

		if (!_highMax.IsFormed || !_lowMax.IsFormed)
			return;

		var hh = (candle.HighPrice - highMinVal) + (candle.HighPrice - highMidleVal) + (candle.HighPrice - highMaxVal);
		var ll = (lowMinVal - candle.LowPrice) + (lowMidleVal - candle.LowPrice) + (lowMaxVal - candle.LowPrice);

		var bullsVal = _bullsEma.Process(new DecimalIndicatorValue(_bullsEma, hh, candle.OpenTime) { IsFinal = true }).ToDecimal();
		var bearsVal = _bearsEma.Process(new DecimalIndicatorValue(_bearsEma, ll, candle.OpenTime) { IsFinal = true }).ToDecimal();

		if (!_bullsEma.IsFormed || !_bearsEma.IsFormed)
			return;

		if (!IsFormedAndOnlineAndAllowTrading())
			return;

		if (_prevBulls <= _prevBears && bullsVal > bearsVal && Position <= 0)
		{
			if (Position < 0)
				BuyMarket();
			BuyMarket();
		}
		else if (_prevBulls >= _prevBears && bullsVal < bearsVal && Position >= 0)
		{
			if (Position > 0)
				SellMarket();
			SellMarket();
		}

		_prevBulls = bullsVal;
		_prevBears = bearsVal;
	}
}