bb_upper
Bollinger Bands Upper Band (MA + num_stdev * stdev)
bb_upper(source, period, num_stdev, matype="sma")
Parameters
| Name | Type | Description |
|---|---|---|
source |
field | Data series (typically close) |
period |
int | MA and stdev period |
num_stdev |
float | Number of standard deviations |
Formula
BB Upper = MA(source, period) + num_stdev * stdev(source, period)Examples
close > bb_upper(close, 20, 2); // Price breakout above upper band/* price pierced above upper band, but closed below */
high > bb_upper(close, 20, 2.5) and close < bb_upper(close, 20, 2.5);/* upper bollinger band rising (expanding volatility) for 3 consecutive bars */
rising(bb_upper(close, 20, 2.0), 3) == true;/* upper bollinger band falling (contracting volatility) for 3 consecutive bars */
falling(bb_upper(close, 20, 2.0), 3) == true;Returns
float
Range
period is bound by matype's MA family (2-210 ema, 2-105 wilder) or the 2-400 windowed range for the default sma/wma, whichever is tighter, since the same period also sizes stdev()