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

NameTypeSummary
Bottom PropertyLower Bollinger Band.
Main PropertyMoving Average (Middle Bollinger Band).
Top PropertyUpper 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