A quantitative backtest framework comparing 5 strategies (BuyHold QQQ / Timing QQQ / Timing QLD / Timing TQQQ / Combo 60-30-10) using QQQ SMA200 as market regime signal with dip-based DCA entry. 基于QQQ SMA200牛熊择时，对比五种策略（买入持有/QQQ择时/QLD择时/TQQQ择时/60-30-10混合组合）的量化回测框架，支持分批回调建仓。