2 tk (1in %) 1 sl + color.plot

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © calcajack

//@version=4
strategy("Bollinger Bands Strategy", shorttitle="BB Strategy", overlay=true, default_qty_type=strategy.percent_of_equity, default_qty_value=5)

//definisco gli INPUT

standard_dev = input(20, "deviazione standard", input.integer, minval=1, maxval=50)
offset = input(2,"offset", input.float, minval=0.1, maxval=10)

// calcolo e disegno le tre bande

centralBand = sma(close, 20)
plot(centralBand, "SMA", color.new(color.red, 50) )

upperBand = centralBand + stdev(close, standard_dev)*offset
plot(upperBand, "Upper Band", color.new(color.blue, 25) )

lowerBand = centralBand - stdev(close, standard_dev)*offset
plot(lowerBand, "Lower Band", color.new(color.blue, 25) )

//plot(candleClose, "candleClose", color.new(color.yellow, 0) )


//condizioni per apertura Long

openLong = crossover(close, lowerBand)
strategy.entry("long", true,when=openLong)

//condizioni per apertura Short

openShort = crossunder(close, upperBand)
strategy.entry("short", false,when=openShort)

//condizioni per chiusura Long

closeLong1 = crossover(close, centralBand)
closeLong2 = crossover(high, upperBand)
strategy.close("long", when=closeLong1, qty_percent=66)
strategy.close("long", when=closeLong2)
strategy.close("long", when=crossunder(close,centralBand))

//condizioni per chiusura Short

closeShort1 = crossunder(close, centralBand)
closeShort2 = crossunder(low, lowerBand)
strategy.close("short", when=closeShort1, qty_percent=66)
strategy.close("short", when=closeShort2)
strategy.close("short", when=crossover(close,centralBand))