Maximize risk-adjusted return (Sharpe/Calmar) on EUR/USD 15-min data. EMA 50/200 cross provides the primary trend regime filter. ATR 14 gates entries by volatility (min_atr avoids dead-market noise). XGBoost chosen for its ability to capture non-linear feature interactions. Conservative depth=4 and regularisation (alpha/lambda) prevent overfitting on the relatively short 1-year window. 2:1 reward/risk (SL=0.5%, TP=1.0%) ensures positive expectancy even at modest hit-rates. Session filter 06-20 U

Maximise risk-adjusted return on USD/CAD 15-min bars. XGBoost with deep feature set (multi-period SMA distances and crossovers, RSI, MACD, Bollinger Bands, ATR, candle structure, lagged returns). Regularised tree ensemble (gamma, L1/L2, min_child_weight) prevents overfitting on the ~1-year window. 2:1 TP:SL ratio locks in positive expectancy; session filter restricts trading to liquid London/NY overlap.

Maximize risk-adjusted return (Sharpe/Calmar) on AUD/USD 15-min. XGBoost with depth-4 trees and conservative regularization (reg_lambda=1.5, min_child_weight=5) to reduce overfitting on FX data. 2:1 RR (SL=0.5%, TP=1.0%) ensures positive expectancy with ~40%+ win rate. Subsample + colsample add stochastic diversity. 500 estimators with lr=0.04 balances bias-variance. Threshold 0.55 filters marginal signals.