Evidence
Across 66 historical occurrences, the QQQ / SMH / SOXX basket returned on average 11.7% over the next 63 trading days (median 11.0%), against SPY — an excess of 5.0%. The forward window was positive 83.3% of the time.
Interpretation
On this evidence the setup historically added excess return versus SPY at the 63-day horizon.
Metrics by holding period
| Holding (days) | n | Avg | Median | Win rate | Excess | Worst |
|---|---|---|---|---|---|---|
| 21 | 72 | 2.5% | 2.0% | 55.6% | 2.3% | -20.8% |
| 63 | 66 | 11.7% | 11.0% | 83.3% | 5.0% | -28.6% |
| 126 | 66 | 20.2% | 21.9% | 84.8% | 7.3% | -32.2% |
Validation (63-day) — FAIL
| Stage | Result |
|---|---|
| training | ✅ passed |
| validation | ❌ n=15 < 20 |
| oos | ❌ n=3 < 20 |
| random-entry null | ✅ beats random entry · 95% CI [4.9%, 11.3%] |
| ±15% robustness | ✅ holds · edge holds same-sign under all ±15% parameter shifts |
Considerations
Ways investors commonly express a view like this include broad sector/theme ETFs (e.g. QQQ). Position sizing, entry timing and risk control remain the investor's own decisions.
Reality check
n=66. A historical observation, not a prediction or recommendation; regimes change and past behaviour need not repeat.