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Bollinger Bands®

Created by John Bollinger, Bollinger Bands price channels depict volatility as standard deviation boundary line range from a moving average of price. Bollinger Bands® is a registered trademark of John A. Bollinger. [Discuss] 💬

// C# usage syntax
IEnumerable<BollingerBandsResult> results =
  quotes.GetBollingerBands(lookbackPeriods, standardDeviations);

Parameters

lookbackPeriods int - Number of periods (N) for the center line moving average. Must be greater than 1 to calculate; however we suggest a larger period for statistically appropriate sample size. Default is 20.

standardDeviations double - Width of bands. Standard deviations (D) from the moving average. Must be greater than 0. Default is 2.

Historical quotes requirements

You must have at least N periods of quotes to cover the warmup periods.

quotes is a collection of generic TQuote historical price quotes. It should have a consistent frequency (day, hour, minute, etc). See the Guide for more information.

Response

IEnumerable<BollingerBandsResult>

• This method returns a time series of all available indicator values for the quotes provided.
• It always returns the same number of elements as there are in the historical quotes.
• It does not return a single incremental indicator value.
• The first N-1 periods will have null values since there’s not enough data to calculate.

BollingerBandsResult

Date DateTime - Date from evaluated TQuote

Sma double - Simple moving average (SMA) of price (center line)

UpperBand double - Upper line is D standard deviations above the SMA

LowerBand double - Lower line is D standard deviations below the SMA

PercentB double - %B is the location within the bands. (Price-LowerBand)/(UpperBand-LowerBand)

ZScore double - Z-Score of current price (number of standard deviations from mean)

Width double - Width as percent of SMA price. (UpperBand-LowerBand)/Sma

Utilities

• .Condense()
• .Find(lookupDate)
• .RemoveWarmupPeriods()
• .RemoveWarmupPeriods(qty)

See Utilities and helpers for more information.

Chaining

This indicator may be generated from any chain-enabled indicator or method.

// example
var results = quotes
    .Use(CandlePart.HL2)
    .GetBollingerBands(..);

Results can be further processed on PercentB with additional chain-enabled indicators.

// example
var results = quotes
    .GetBollingerBands(..)
    .GetRsi(..);