Own SPY when the market’s long‑term trend is up. If not, use QQQ’s short‑term “oversold” reading: go defensive (T‑bills plus a low‑vol mix of staples and gold) unless things are very washed out—then take a contrarian swing in tech (XLK).

1) If SPY (broad US stocks) is above its 200‑day average price (long‑term trend), hold SPY. 2) Else check QQQ’s 10‑day RSI (quick “oversold” gauge; ≤30 = very sold). If RSI > 30, go defensive: half in BIL (T‑bills) and half in XLP+GLD, tilted toward the calmer one over the last month. If RSI ≤ 30, switch to XLK (tech) for a rebound try.

Rule-based strategy beats SPY on risk-adjusted return and downside protection: oos annualized return ~31% vs 23.5%, Sharpe ~1.58 vs 1.24, max drawdown ~11.3% vs 18.8%, beta ~0.83, Calmar ~2.75. Higher returns with steadier risk.