Bollinger Squeeze Breakout

// This Pine Script v5 strategy is licensed under the MIT License
// Tested with Backtrex (https://backtrex.com) on 10 years of M1 data
// Anti-repainting: all references use close[1]

//@version=5
strategy("Bollinger Squeeze Breakout", overlay=true, default_qty_type=strategy.percent_of_equity, default_qty_value=2)

// Inputs
bbLen = input.int(20, "Bollinger Band Length")
bbMult = input.float(2.0, "Bollinger Band Multiplier")
squeezeFactor = input.float(0.75, "Squeeze Threshold (% of avg width)")
lookback = input.int(20, "Squeeze Lookback Period")

// Bollinger Bands (using close[1] to prevent repainting)
basis = ta.sma(close[1], bbLen)
dev = bbMult * ta.stdev(close[1], bbLen)
upper = basis + dev
lower = basis - dev

// Band width and squeeze detection
bbWidth = upper - lower
avgWidth = ta.sma(bbWidth, lookback)
isSqueeze = bbWidth < avgWidth * squeezeFactor
wasSqueeze = isSqueeze[1]

// Breakout signals (squeeze must have occurred in recent bars)
recentSqueeze = ta.barssince(isSqueeze) < 5
longSignal = recentSqueeze and close[1] > upper and close[2] <= upper[1]
shortSignal = recentSqueeze and close[1] < lower and close[2] >= lower[1]

// Risk calculation
distToMiddle = math.abs(close - basis)

// Execute trades
if longSignal
    sl = basis
    tp = close + distToMiddle * 2
    strategy.entry("Long", strategy.long)
    strategy.exit("Long Exit", "Long", stop=sl, limit=tp)

if shortSignal
    sl = basis
    tp = close - distToMiddle * 2
    strategy.entry("Short", strategy.short)
    strategy.exit("Short Exit", "Short", stop=sl, limit=tp)

// Plots
plot(basis, "SMA 20", color=color.gray)
plot(upper, "Upper Band", color=color.blue)
plot(lower, "Lower Band", color=color.blue)
bgcolor(isSqueeze ? color.new(color.yellow, 90) : na, title="Squeeze Zone")