Each month, switch 100% between SPY (U.S. large stocks) and TLT (long‑term U.S. Treasury bonds) based on which had the stronger last 3‑month return. Aims to ride strength and sidestep weakness with a simple, all‑in approach.

Once a month, it compares the last 3 months of performance for SPY (a fund of the 500 biggest U.S. stocks) and TLT (a fund of long‑term U.S. Treasury bonds). If SPY did better, it holds SPY 100%. If TLT did better, it holds TLT 100%. It never holds both, and repeats monthly.

Disciplined SPY/TLT monthly rotation offers diversification with a low beta (~0.63) and lower volatility, helping cushion risk when stocks wobble. Out-of-sample returns are modest—use as a risk-management sleeve to complement the S&P 500.