BollingerBands

Summary

Bollinger Bands are used to confirm signals. The bands indicate overbought and oversold levels relative to a moving average.

Remarks

Bollinger bands widen in volatile market periods, and contract during less volatile periods. Tightening of the bands is often used a signal that there will shortly be a sharp increase in market volatility.

Syntax

public interface BollingerBands

Members

Name	Type	Summary
Bottom	Property	Lower Bollinger Band.
Main	Property	Moving Average (Middle Bollinger Band).
Top	Property	Upper Bollinger Band.

Example 1

//...
[Robot]
public class SampleRobot : Robot
//...
[Parameter("Source")]
public DataSeries Source { get; set; }
[Parameter("BandPeriods", DefaultValue = 14)]
public int BandPeriod { get; set; }
[Parameter("Std", DefaultValue = 14)]
public int std { get; set; }
[Parameter("MAType")]
public MovingAverageType MAType { get; set; }
//...
private BollingerBands boll;
//...
protected override void OnStart()
{
    boll = Indicators.BollingerBands(Source,BandPeriod,std,MAType);
}
protected override void OnBar()
{
    Print("Current Main Bollinger Band's price is: {0}", boll.Main.LastValue);
    Print("Current Bottom Bollinger Band's price is: {0}", boll.Bottom.LastValue);
    Print("Current Top Bollinger Band's price is: {0}", boll.Top.LastValue);
}
//...

Example 2

using cAlgo.API;
using cAlgo.API.Indicators;
namespace cAlgo.Robots
{
    /// 
    /// This sample cBot shows how to use the Bollinger Bands indicator
    /// 
    [Robot(TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class BollingerBandsSample : Robot
    {
        private double _volumeInUnits;
        private BollingerBands _bollingerBands;
        [Parameter("Volume (Lots)", DefaultValue = 0.01)]
        public double VolumeInLots { get; set; }
        [Parameter("Label", DefaultValue = "Sample")]
        public string Label { get; set; }
        [Parameter("Source")]
        public DataSeries Source { get; set; }
        public Position[] BotPositions
        {
            get
            {
                return Positions.FindAll(Label);
            }
        }
        protected override void OnStart()
        {
            _volumeInUnits = Symbol.QuantityToVolumeInUnits(VolumeInLots);
            _bollingerBands = Indicators.BollingerBands(Source, 14, 2, MovingAverageType.Exponential);
        }
        protected override void OnBar()
        {
            if (Bars.LowPrices.Last(1) <= _bollingerBands.Bottom.Last(1) && Bars.LowPrices.Last(2) > _bollingerBands.Bottom.Last(2))
            {
                ClosePositions(TradeType.Sell);
                ExecuteMarketOrder(TradeType.Buy, SymbolName, _volumeInUnits, Label);
            }
            else if (Bars.HighPrices.Last(1) >= _bollingerBands.Top.Last(1) && Bars.HighPrices.Last(2) < _bollingerBands.Top.Last(2))
            {
                ClosePositions(TradeType.Buy);
                ExecuteMarketOrder(TradeType.Sell, SymbolName, _volumeInUnits, Label);
            }
        }
        private void ClosePositions(TradeType tradeType)
        {
            foreach (var position in BotPositions)
            {
                if (position.TradeType != tradeType) continue;
                ClosePosition(position);
            }
        }
    }
}

Reference