NinjaScript > Language Reference > Indicator Methods >
On Balance Volume (OBV)
OBV is a simple indicator that adds a period's volume when the close is up and subtracts the period's volume when the close is down. A cumulative total of the volume additions and subtractions forms the OBV line. This line can then be compared with the price chart of the underlying security to look for divergences or confirmation.
... Courtesy of StockCharts
double; Accessing this method via an index value [int barsAgo] returns the indicator value of the referenced bar.
You can view this indicator method source code by selecting the menu Tools > Edit NinjaScript > Indicator within the NinjaTrader Control Center window.