Own SPY when the market is trending up; if tech is extremely “hot,” switch to a short‑term volatility play (UVXY). When the trend weakens, shift mostly to T‑bills with small SPY and Berkshire stakes.

Uses simple trend + “overheating” checks. - SPY = S&P 500 fund. BRK/B = Berkshire Hathaway. SHV = T‑bills. UVXY = jumps when market fear spikes; decays if held. TQQQ = 3× tech fund used only as a heat gauge. Rules: If SPY > its 7‑day EMA (short average), own SPY—unless TQQQ’s 10‑day RSI (0–100 “hotness”) >79; then hold UVXY briefly. If SPY ≤ EMA, go defensive: ~60% SHV, 20% SPY, 20% BRK/B.

Trend-driven strategy blends SPY exposure with selective UVXY hedges and cash when risk rises. It targets strong risk-adjusted returns (out-of-sample Calmar 7.12; Sharpe 2.22) versus the S&P 500, with downside protection via defensive shifts.