// Bullish Reversal: EMA 8 crosses above EMA 13, price above EMA 21, with volume surge bullishReversal = ta.crossover(ema8, ema13) and close > ema21 and volSurge
// Bearish Reversal: EMA 8 crosses below EMA 13, price below EMA 21, with volume surge bearishReversal = ta.crossunder(ema8, ema13) and close < ema21 and volSurge