Bollinger Bands overlay displays upper and lower limits of the price movements over the time. These are volatility bands based on standard deviation, and are placed above and below a moving average. Bollinger Bands are helpful in providing a relative definition of high and low price. Prices plotted near the upper band are considered high, while prices near the lower band are low. The width of the band depicts the measure of volatility. The price values touching the top of the Bollinger Band are supposed to be over extended above the intermediate trend, and the prices touching the bottom of the Bollinger band are supposed to be over extended below the intermediate trend.
To use Bollinger Bands overlay in FinancialChart, add a FinancialChart control to your application and bind it to an appropriate data source. ItemsSource object enables data binding or populating data in FinancialChart. BollingerBands class exposes Multiplier property, to specify standard deviations for upper and lower bands, and IndicatorBase class provides the Period property, which takes integer value for calculating Simple Moving Average for the middle band. Based on the values of these properties, data points for Bollinger Bands overlay are calculated and plotted on FinancialChart.
FinancialChart also enables users to fetch the calculated Lower y values, Middle y values, Upper y values, and x values in the run time, for the purpose of creating alerts in application or maintaining logs while working with dynamic data.
The following example considers stock data for a company Box Inc. over a period of time and plots Bollinger Bands overlay on the same financial chart, as shown in the image above. The example uses data from a json file, and DataService.cs class is created to access this json file.
Make sure to add the following references in DataService.cs:
Json Data
[ { "date": "01/23/15", "open": 20.2, "high": 24.73, "low": 20.16, "close": 23.23, "volume": 42593223 }, { "date": "01/26/15", "open": 23.67, "high": 24.39, "low": 22.5, "close": 22.6, "volume": 8677164 }, { "date": "01/27/15", "open": 22, "high": 22.47, "low": 21.17, "close": 21.3, "volume": 3272512 }, { "date": "01/28/15", "open": 21.62, "high": 21.84, "low": 19.6, "close": 19.78, "volume": 5047364 }, { "date": "01/29/15", "open": 19.9, "high": 19.95, "low": 18.51, "close": 18.8, "volume": 3419482 }, { "date": "01/30/15", "open": 18.47, "high": 19.48, "low": 18.22, "close": 18.81, "volume": 2266439 }, { "date": "02/02/15", "open": 19.18, "high": 19.3, "low": 18.01, "close": 18.02, "volume": 2071168 }, { "date": "02/03/15", "open": 18.22, "high": 18.64, "low": 18.12, "close": 18.24, "volume": 1587435 }, { "date": "02/04/15", "open": 18.2, "high": 18.35, "low": 17, "close": 17.1, "volume": 2912224 }, { "date": "02/05/15", "open": 17.3, "high": 17.31, "low": 16.41, "close": 16.66, "volume": 2682187 }, { "date": "02/06/15", "open": 17.39, "high": 18.88, "low": 17.21, "close": 18.12, "volume": 3929164 }, { "date": "02/09/15", "open": 18.86, "high": 19.95, "low": 18.45, "close": 19.6, "volume": 3226650 }, { "date": "02/10/15", "open": 20.5, "high": 21, "low": 19.63, "close": 20.99, "volume": 2804409 }, { "date": "02/11/15", "open": 20.89, "high": 21, "low": 20.2, "close": 20.96, "volume": 1698365 }, { "date": "02/12/15", "open": 20.66, "high": 20.85, "low": 19.75, "close": 20.17, "volume": 1370320 }, { "date": "02/13/15", "open": 20.19, "high": 20.68, "low": 20, "close": 20.18, "volume": 711951 }, { "date": "02/17/15", "open": 19.5, "high": 20.1, "low": 18.8, "close": 19.05, "volume": 2093602 }, { "date": "02/18/15", "open": 18.31, "high": 18.5, "low": 17.96, "close": 18, "volume": 1849490 }, { "date": "02/19/15", "open": 18.33, "high": 19.25, "low": 17.91, "close": 18.96, "volume": 1311518 }, { "date": "02/20/15", "open": 18.68, "high": 19.3, "low": 18.65, "close": 18.85, "volume": 1001692 }, { "date": "02/23/15", "open": 18.8, "high": 18.89, "low": 18.11, "close": 18.21, "volume": 670087 }, { "date": "02/24/15", "open": 18.46, "high": 19, "low": 18.27, "close": 18.83, "volume": 759263 }, { "date": "02/25/15", "open": 18.83, "high": 19.48, "low": 18.47, "close": 18.67, "volume": 915580 }, { "date": "02/26/15", "open": 18.64, "high": 19.2, "low": 18.64, "close": 18.94, "volume": 461283 }, { "date": "02/27/15", "open": 18.8, "high": 19.12, "low": 18.55, "close": 18.66, "volume": 617199 }, { "date": "03/02/15", "open": 18.66, "high": 19.09, "low": 18.65, "close": 18.79, "volume": 519605 }, { "date": "03/03/15", "open": 18.79, "high": 19.21, "low": 18.45, "close": 18.59, "volume": 832415 }, { "date": "03/04/15", "open": 18.64, "high": 19.05, "low": 18.32, "close": 19, "volume": 539688 }, { "date": "03/05/15", "open": 19.2, "high": 19.2, "low": 18.8, "close": 19.14, "volume": 486149 }, { "date": "03/06/15", "open": 19.03, "high": 19.1, "low": 18.7, "close": 18.91, "volume": 685659 }, { "date": "03/09/15", "open": 18.98, "high": 20.15, "low": 18.96, "close": 19.4, "volume": 1321363 }, { "date": "03/10/15", "open": 19.3, "high": 19.8, "low": 18.85, "close": 19.64, "volume": 615743 }, { "date": "03/11/15", "open": 20.08, "high": 20.65, "low": 19.24, "close": 20.53, "volume": 2167167 }, { "date": "03/12/15", "open": 17.17, "high": 18.2, "low": 16.76, "close": 18.2, "volume": 6837638 }, { "date": "03/13/15", "open": 18.05, "high": 18.05, "low": 17.3, "close": 17.88, "volume": 1715629 }, { "date": "03/16/15", "open": 17.91, "high": 18, "low": 17.01, "close": 17.13, "volume": 1321313 }, { "date": "03/17/15", "open": 17.28, "high": 17.37, "low": 16.6, "close": 17.12, "volume": 1272242 }, { "date": "03/18/15", "open": 17.1, "high": 17.27, "low": 16.91, "close": 17.01, "volume": 530063 }, { "date": "03/19/15", "open": 17, "high": 17.28, "low": 17, "close": 17.06, "volume": 536427 }, { "date": "03/20/15", "open": 17.13, "high": 17.24, "low": 16.88, "close": 17.21, "volume": 1320237 }, { "date": "03/23/15", "open": 17.21, "high": 17.23, "low": 17.01, "close": 17.11, "volume": 509798 }, { "date": "03/24/15", "open": 17.02, "high": 17.18, "low": 16.82, "close": 17, "volume": 962149 }, { "date": "03/25/15", "open": 16.92, "high": 16.99, "low": 16.82, "close": 16.97, "volume": 565673 }, { "date": "03/26/15", "open": 16.83, "high": 17.56, "low": 16.83, "close": 17.54, "volume": 884523 }, { "date": "03/27/15", "open": 17.58, "high": 18.3, "low": 17.11, "close": 18.3, "volume": 705626 }, { "date": "03/30/15", "open": 18.5, "high": 19.4, "low": 18.4, "close": 19.05, "volume": 1151620 }, { "date": "03/31/15", "open": 19.08, "high": 20.58, "low": 18.4, "close": 19.75, "volume": 2020679 }, { "date": "04/01/15", "open": 19.69, "high": 19.69, "low": 18.55, "close": 18.65, "volume": 961078 }, { "date": "04/02/15", "open": 18.56, "high": 18.66, "low": 17.85, "close": 17.9, "volume": 884233 }, { "date": "04/06/15", "open": 17.78, "high": 17.94, "low": 17.51, "close": 17.66, "volume": 605252 }, { "date": "04/07/15", "open": 17.62, "high": 17.9, "low": 17.53, "close": 17.61, "volume": 591988 }, { "date": "04/08/15", "open": 17.64, "high": 17.85, "low": 17.32, "close": 17.36, "volume": 618855 }, { "date": "04/09/15", "open": 17.33, "high": 17.54, "low": 17.1, "close": 17.1, "volume": 761855 }, { "date": "04/10/15", "open": 17.08, "high": 17.36, "low": 17, "close": 17.05, "volume": 568373 }, { "date": "04/13/15", "open": 17.24, "high": 17.26, "low": 16.81, "close": 17.1, "volume": 667142 }, { "date": "04/14/15", "open": 17.1, "high": 17.89, "low": 17.02, "close": 17.52, "volume": 870138 }, { "date": "04/15/15", "open": 17.6, "high": 17.99, "low": 17.5, "close": 17.69, "volume": 530456 }, { "date": "04/16/15", "open": 17.95, "high": 18, "low": 17.6, "close": 17.82, "volume": 548730 }, { "date": "04/17/15", "open": 17.75, "high": 17.79, "low": 17.5, "close": 17.79, "volume": 446373 }, { "date": "04/20/15", "open": 17.63, "high": 17.98, "low": 17.52, "close": 17.93, "volume": 487017 }, { "date": "04/21/15", "open": 17.96, "high": 17.98, "low": 17.71, "close": 17.92, "volume": 320302 }, { "date": "04/22/15", "open": 17.88, "high": 18.33, "low": 17.57, "close": 18.29, "volume": 644812 }, { "date": "04/23/15", "open": 18.29, "high": 18.61, "low": 18.18, "close": 18.28, "volume": 563879 }, { "date": "04/24/15", "open": 18.5, "high": 18.5, "low": 17.61, "close": 17.75, "volume": 650762 }, { "date": "04/27/15", "open": 17.97, "high": 18.05, "low": 17.45, "close": 17.57, "volume": 437294 }, { "date": "04/28/15", "open": 17.65, "high": 17.79, "low": 17.39, "close": 17.5, "volume": 224519 }, { "date": "04/29/15", "open": 17.68, "high": 17.68, "low": 17.1, "close": 17.21, "volume": 495706 }, { "date": "04/30/15", "open": 17.22, "high": 17.3, "low": 17, "close": 17.11, "volume": 391040 }, { "date": "05/01/15", "open": 17.11, "high": 17.55, "low": 16.85, "close": 17.5, "volume": 563075 }, { "date": "05/04/15", "open": 17.56, "high": 17.85, "low": 17.3, "close": 17.4, "volume": 253138 }, { "date": "05/05/15", "open": 17.68, "high": 17.68, "low": 17.09, "close": 17.43, "volume": 290935 }, { "date": "05/06/15", "open": 17.48, "high": 17.48, "low": 17, "close": 17.04, "volume": 313662 }, { "date": "05/07/15", "open": 17.05, "high": 17.19, "low": 16.92, "close": 17.04, "volume": 360284 }, { "date": "05/08/15", "open": 17.13, "high": 17.21, "low": 16.91, "close": 17.1, "volume": 297653 }, { "date": "05/11/15", "open": 17.16, "high": 17.44, "low": 17.13, "close": 17.31, "volume": 268504 }, { "date": "05/12/15", "open": 17.28, "high": 17.44, "low": 16.99, "close": 17.24, "volume": 376961 }, { "date": "05/13/15", "open": 17.24, "high": 17.3, "low": 17.06, "close": 17.2, "volume": 244617 }, { "date": "05/14/15", "open": 17.24, "high": 17.25, "low": 17.02, "close": 17.08, "volume": 252526 }, { "date": "05/15/15", "open": 17.06, "high": 17.16, "low": 16.95, "close": 16.95, "volume": 274783 }, { "date": "05/18/15", "open": 16.95, "high": 17.01, "low": 16.76, "close": 16.87, "volume": 418513 }, { "date": "05/19/15", "open": 16.93, "high": 16.94, "low": 16.6, "close": 16.83, "volume": 367660 }, { "date": "05/20/15", "open": 16.8, "high": 16.9, "low": 16.65, "close": 16.86, "volume": 297914 }, { "date": "05/21/15", "open": 16.9, "high": 17.08, "low": 16.79, "close": 16.88, "volume": 229346 }, { "date": "05/22/15", "open": 16.9, "high": 17.05, "low": 16.85, "close": 17, "volume": 253279 }, { "date": "05/26/15", "open": 17.03, "high": 17.08, "low": 16.86, "close": 17.01, "volume": 212640 }, { "date": "05/27/15", "open": 17.01, "high": 17.99, "low": 16.87, "close": 17.75, "volume": 857109 }, { "date": "05/28/15", "open": 17.77, "high": 17.77, "low": 17.44, "close": 17.62, "volume": 338482 } ]
Make sure to add the following references in code view: