Daily switch: if AGG outperforms SHY over 1 week, hold some Bitcoin; otherwise hold a 3× inverse real‑estate fund (DRV). Most stays in cash. Concentrated, high‑risk, frequently changing positions.

Every day it looks at the past week: did AGG (broad U.S. bonds) beat SHY (short‑term Treasuries)? If yes, it treats that as a friendlier, falling‑rates backdrop and puts about 25% into Bitcoin (BTC), keeping ~75% in cash. If not, it puts ~25% into DRV—a fund that goes up when U.S. real‑estate stocks fall (3× inverse)—and keeps the rest in cash. It holds only one of these at a time and rechecks daily.

Bold, regime-switching sleeve: BTC or 3x inverse REITs with ~75% cash. Out-of-sample: -62% annualized return, -53% max drawdown, negative Sharpe. Not a core S&P substitute—suited only for ultra-tolerant, speculative diversification.