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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.

Signature 

1
public abstract interface BollingerBands

Namespace

cAlgo.API.Indicators

Examples

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 //...
 [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);
 }
 //...

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 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);
             }
         }
     }
 }

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 import clr
 clr.AddReference("cAlgo.API")
 # Import cAlgo API types
 from cAlgo.API import *
 # Import trading wrapper functions
 from robot_wrapper import *
 class Test():
     def on_start(self):
         # Source, Periods, Std, and MaType are parameters defined in C# file of cBot
         self.bollingerBands = api.Indicators.BollingerBands(api.Source, api.Periods, api.Std, api.MaType)
     def on_bar(self):
         print(f"Current Main Bollinger Band's price is: {self.bollingerBands.Main.LastValue}")
         print(f"Current Bottom Bollinger Band's price is: {self.bollingerBands.Bottom.LastValue}")
         print(f"Current Top Bollinger Band's price is: {self.bollingerBands.Top.LastValue}")

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 """
 VolumeInLots, Source, Periods, StandardDeviations, MaType, and Label are parameters defined in C# file of cBot.
 """
 import clr
 clr.AddReference("cAlgo.API")
 # Import cAlgo API types
 from cAlgo.API import *
 # Import trading wrapper functions
 from robot_wrapper import *
 class BollingerBandsSample():
     def on_start(self):
         self.volumeInUnits = api.Symbol.QuantityToVolumeInUnits(api.VolumeInLots)
         self.bollingerBands = api.Indicators.BollingerBands(api.Source, api.Periods, api.StandardDeviations, api.MaType)
     def on_bar_closed(self):
         if api.Bars.LowPrices.Last(0) <= self.bollingerBands.Bottom.Last(0) and api.Bars.LowPrices.Last(1) > self.bollingerBands.Bottom.Last(1):
             self.close_positions(TradeType.Sell)
             api.ExecuteMarketOrder(TradeType.Buy, api.SymbolName, self.volumeInUnits, api.Label)
         elif api.Bars.HighPrices.Last(0) >= self.bollingerBands.Top.Last(0) and api.Bars.HighPrices.Last(1) < self.bollingerBands.Top.Last(1):
             self.close_positions(TradeType.Buy)
             api.ExecuteMarketOrder(TradeType.Sell, api.SymbolName, self.volumeInUnits, api.Label)
     def get_bot_positions(self):
         return api.Positions.FindAll(api.Label)
     def close_positions(self, tradeType):
         for position in self.get_bot_positions():
             if position.TradeType != tradeType:
                 continue
             api.ClosePosition(position)

Properties

Main

Summary

Moving Average (Middle Bollinger Band).

Signature 

1
public abstract IndicatorDataSeries Main {get;}

Return Value

IndicatorDataSeries

Examples

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 //...
 [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);
 }
 //...

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 import clr
 clr.AddReference("cAlgo.API")
 # Import cAlgo API types
 from cAlgo.API import *
 # Import trading wrapper functions
 from robot_wrapper import *
 class Test():
     def on_start(self):
         # Source, Periods, Std, and MaType are parameters defined in C# file of cBot
         self.bollingerBands = api.Indicators.BollingerBands(api.Source, api.Periods, api.Std, api.MaType)
     def on_bar(self):
         print(f"Current Main Bollinger Band's price is: {self.bollingerBands.Main.LastValue}")

Top

Summary

Upper Bollinger Band.

Signature 

1
public abstract IndicatorDataSeries Top {get;}

Return Value

IndicatorDataSeries

Examples

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 //...
 [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 Top Bollinger Band's price is: {0}", boll.Top.LastValue);
 }
 //...

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 import clr
 clr.AddReference("cAlgo.API")
 # Import cAlgo API types
 from cAlgo.API import *
 # Import trading wrapper functions
 from robot_wrapper import *
 class Test():
     def on_start(self):
         # Source, Periods, Std, and MaType are parameters defined in C# file of cBot
         self.bollingerBands = api.Indicators.BollingerBands(api.Source, api.Periods, api.Std, api.MaType)
     def on_bar(self):
         print(f"Current Top Bollinger Band's price is: {self.bollingerBands.Top.LastValue}")

Bottom

Summary

Lower Bollinger Band.

Signature 

1
public abstract IndicatorDataSeries Bottom {get;}

Return Value

IndicatorDataSeries

Examples

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 //...
 [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 Bottom Bollinger Band's price is: {0}", boll.Bottom.LastValue);
 }
 //...

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 import clr
 clr.AddReference("cAlgo.API")
 # Import cAlgo API types
 from cAlgo.API import *
 # Import trading wrapper functions
 from robot_wrapper import *
 class Test():
     def on_start(self):
         # Source, Periods, Std, and MaType are parameters defined in C# file of cBot
         self.bollingerBands = api.Indicators.BollingerBands(api.Source, api.Periods, api.Std, api.MaType)
     def on_bar(self):
         print(f"Current Bottom Bollinger Band's price is: {self.bollingerBands.Bottom.LastValue}")