Backtested and hypothetical results, shown for educational purposes only — not investment advice. Past performance does not indicate future results.
SP SPY — No setup$764.29 · 2026-09-11
SPY fades the prior day (mean-reverts) at the daily horizon.
Nothing stretched right now — no short-term setup.
| Rule | Days held | Avg / day | Win rate | Total | CAGR | Sharpe | Max DD |
|---|---|---|---|---|---|---|---|
| ■ After a DOWN close | 3,825 (45%) | +0.079% | 55.5% | +1,353% | +8.3% | 0.64 | -30.8% |
| ■ After an UP close | 4,573 (54%) | +0.022% | 52.9% | +115% | +2.3% | 0.25 | -67.7% |
| ■ Bottom 10% RSI(2) | 847 (10%) | +0.270% | 59.7% | +775% | +6.7% | 0.80 | -16.0% |
| ■ Top 10% RSI(2) | 847 (10%) | -0.017% | 50.9% | -15% | -0.5% | -0.12 | -33.8% |
Some assets mean-revert at short horizons (a sharp move tends to partly reverse); others trend (a move tends to continue). At the daily close-to-close horizon the reversal shows up cleanly and consistently in the broad equity indices and mostly breaks down elsewhere — commodities, crypto, and individual stocks carry their own momentum. The names above are the ones where it holds up.
RSI(2) is a 2-day momentum oscillator — below ~10 is short-term oversold, above ~90 overbought. Distance from the 50-day average is measured in standard deviations (z-score). Streak counts consecutive up or down closes. For each, we show what happened over the next 1–5 days, historically.
The strategy table pairs each dip-buy rule against its opposite — day-after-a-down-close vs day-after-an-up-close, and the bottom vs top RSI(2) decile. Both legs of a pair are held one day and trade a similar number of days, so raw returns compare fairly (unlike buy & hold, which wins on total return simply by always being invested). Avg / day — mean return on the days the rule is in the market — is the cleanest apples-to-apples number. Frictionless: no commissions or slippage. A character test, not a tradeable system. Past behaviour is not a forecast.