CONTEXT:
UNIVERSE: SP500
BASE_TZ: America/New_York
CAPITAL: 1_000_000

PARAMS:
sym="{{sym}}",  // Symbol placeholder for runtime injection
fast_ema=5,      // Fast EMA period for breakout confirmation
slow_ema=6,     // Slow EMA period for trend filter
vol_min=1_000_000, // Minimum volume filter to avoid low-float stocks
atr_period=14,   // ATR period for volatility and risk calculation
atr_mult=2.5,    // ATR multiplier for trailing stop
bb_period=14,    // Bollinger Bands period for volatility contraction
bb_dev=3,      // Bollinger Bands standard deviation multiplier
risk_frac=0.0793   // Risk fraction for position sizing

STRATEGY "Nexus Revert Pulse-381595 + Mut-46cb0d + Mut-996010 + Mut":
TRIGGER:
// Time gate to skip first 5 minutes of trading day (assuming 9:30 AM ET start, convert to UTC)
TIME_UTC_IN("21:40", "20:00") 
AND
// Volume filter to avoid low-float microcaps
LAST(VOL(sym, 1m)) >= vol_min
AND
// Volatility contraction: price within tight Bollinger Bands
LAST(CLOSE(sym, 1m)) > LOWER(BBANDS(CLOSE(sym, 1m), bb_period, bb_dev))
AND
LAST(CLOSE(sym, 1m)) < UPPER(BBANDS(CLOSE(sym, 1m), bb_period, bb_dev))
AND
// Breakout signal: price crosses above fast EMA
CROSSUNDER(CLOSE(sym, 1m), EMA(CLOSE(sym, 1m), fast_ema))
AND
// Higher timeframe trend filter (5m) for confirmation
EMA(CLOSE(sym, 5m), fast_ema) > EMA(CLOSE(sym, 5m), slow_ema)
ENTRY: MARKET  // Market order for immediate execution on breakout
EXIT:
BARS_SINCE_HIGH(HIGH(sym,1m), 20) > 15
RISK: TRAIL_ATR(atr_period, atr_mult)  // Trailing ATR stop for dynamic risk management
SIZING: FIXED_FRACTION(risk_frac)  // Fixed fraction sizing based on risk tolerance