bollinger_band_strategy.pinescript

//@version=4
// this script was taken from https://kodify.net/tradingview/strategies/bollinger-breakout/ and modified for demonstration purposes
strategy(title="Bollinger Breakout", overlay=true, initial_capital=1000)

smaLength = input(title="SMA Length", type=integer, defval=350)

ubOffset = input(title="Upper Band Offset", type=float, defval=2.5, step=0.5)
lbOffset = input(title="Lower Band Offset", type=float, defval=2.5, step=0.5)

//usePosSize = input(title="Use Position Sizing?", type=bool, defval=true)
//riskPerc   = input(title="Risk %", type=float, defval=0.5, step=0.25)

smaValue = sma(close, smaLength)
stdDev   = stdev(close, smaLength)

upperBand = smaValue + (stdDev * ubOffset)
lowerBand = smaValue - (stdDev * lbOffset)

//riskEquity  = (riskPerc / 100) * strategy.equity
//atrCurrency = (atr(20) * syminfo.pointvalue)
//posSize     = usePosSize ? floor(riskEquity / atrCurrency) : 1

plot(series=smaValue, title="SMA", color=teal)
plot(series=upperBand, title="UB", color=green, linewidth=2)
plot(series=lowerBand, title="LB", color=red, linewidth=2)

enterLong = crossover(close, upperBand)
exitLong  = crossunder(close, smaValue)

enterShort = crossunder(close, lowerBand)
exitShort  = crossover(close, smaValue)

strategy.entry(id="long_entry", long=true, qty=10, when=enterLong)
strategy.entry(id="short_entry", long=false, qty=10, when=enterShort)

strategy.close(id="long_entry", when=exitLong)
strategy.close(id="short_entry", when=exitShort)