SPY trend filter

Hold SPY while it closes above its moving average, hold cash when it closes below. Compared with buying SPY and holding it.

Growth of $10,000 · log scale

Data: MarketParquet daily bars, 2000-01-03 → 2026-10-23, split-adjusted, with delisted stocks. Prices only, without dividends: SPY total return is about 1.5–2 %/yr higher than shown. Sharpe uses a 0 % risk-free rate.