Time-Series Momentum (US S&P 500)
Time-Series Momentum (US S&P 500) backtest. Median Sharpe across 120 parameter sets is -0.31. p-value is 0.39. Max DD is -9.3%. Period: 2022-02-01 to 2026-09-01. Best Sharpe +0.94 is not the representative figure.
Verdict: rejected. The median reaches neither promising (Sharpe > 0.5 and p-value < 0.05) nor marginal (Sharpe > 0.05 and best p-value < 0.10). Primary reason: no_edge. It is not regime, frequency, or cost, and the median does not clear the bar.
What was tested
Time-series momentum follows the sign of each asset's own past return. It is not a cross-sectional ranking. If the median Sharpe is negative, a stretch that worked in one regime is not the result.
Performance summary
Hypothesis
Moskowitz, Ooi, Pedersen (2012): each stock's own past return predicts its future return. Applied to S&P 500 constituents.
Why it didn't work
Across 120 grid combinations, median Sharpe=-0.31, best=0.94. Primary failure mode: no_edge.
Facts (5)
Runs (30)
| run | params | sharpe | UP | FLAT | DOWN |
|---|---|---|---|---|---|
formation_days=20, holding_days=1, threshold_pct=0, cost_bps=5 r-ts-momentum-us-sp500-0000 | cost_bps: 5 holding_days: 1 threshold_pct: 0 | +0.36 | +0.45 | +0.16 | +0.53 |
formation_days=20, holding_days=1, threshold_pct=0, cost_bps=10 r-ts-momentum-us-sp500-0001 | cost_bps: 10 holding_days: 1 threshold_pct: 0 | -0.39 | -0.53 | -0.56 | +0.02 |
formation_days=20, holding_days=1, threshold_pct=0.05, cost_bps=5 r-ts-momentum-us-sp500-0002 | cost_bps: 5 holding_days: 1 threshold_pct: 0.05 | +0.63 | +0.89 | +0.29 | +0.70 |
formation_days=20, holding_days=1, threshold_pct=0.1, cost_bps=5 r-ts-momentum-us-sp500-0004 | cost_bps: 5 holding_days: 1 threshold_pct: 0.1 | +0.94 | +1.38 | +0.31 | +1.07 |
formation_days=20, holding_days=5, threshold_pct=0, cost_bps=10 r-ts-momentum-us-sp500-0007 | cost_bps: 10 holding_days: 5 threshold_pct: 0 | -0.42 | -0.20 | -0.97 | +0.24 |
formation_days=20, holding_days=5, threshold_pct=0.1, cost_bps=10 r-ts-momentum-us-sp500-0011 | cost_bps: 10 holding_days: 5 threshold_pct: 0.1 | -0.25 | -0.18 | -0.46 | +0.05 |
formation_days=20, holding_days=10, threshold_pct=0.05, cost_bps=10 r-ts-momentum-us-sp500-0015 | cost_bps: 10 holding_days: 10 threshold_pct: 0.05 | -0.68 | -0.19 | -1.18 | -0.83 |
formation_days=20, holding_days=20, threshold_pct=0, cost_bps=10 r-ts-momentum-us-sp500-0019 | cost_bps: 10 holding_days: 20 threshold_pct: 0 | -0.28 | -0.04 | -0.80 | -0.04 |
formation_days=20, holding_days=20, threshold_pct=0.1, cost_bps=10 r-ts-momentum-us-sp500-0023 | cost_bps: 10 holding_days: 20 threshold_pct: 0.1 | -0.03 | +0.37 | -0.60 | +0.16 |
formation_days=20, holding_days=60, threshold_pct=0, cost_bps=5 r-ts-momentum-us-sp500-0024 | cost_bps: 5 holding_days: 60 threshold_pct: 0 | -0.13 | +0.15 | -0.41 | -0.27 |
formation_days=20, holding_days=60, threshold_pct=0.1, cost_bps=5 r-ts-momentum-us-sp500-0028 | cost_bps: 5 holding_days: 60 threshold_pct: 0.1 | -0.12 | +0.03 | -0.33 | -0.09 |
formation_days=60, holding_days=1, threshold_pct=0.05, cost_bps=5 r-ts-momentum-us-sp500-0032 | cost_bps: 5 holding_days: 1 threshold_pct: 0.05 | +0.01 | +1.22 | -0.81 | -0.62 |
formation_days=60, holding_days=5, threshold_pct=0, cost_bps=5 r-ts-momentum-us-sp500-0036 | cost_bps: 5 holding_days: 5 threshold_pct: 0 | -0.45 | -0.35 | -0.89 | +0.74 |
formation_days=60, holding_days=5, threshold_pct=0.1, cost_bps=5 r-ts-momentum-us-sp500-0040 | cost_bps: 5 holding_days: 5 threshold_pct: 0.1 | -0.18 | -0.18 | -0.43 | +0.60 |
formation_days=60, holding_days=10, threshold_pct=0.05, cost_bps=5 r-ts-momentum-us-sp500-0044 | cost_bps: 5 holding_days: 10 threshold_pct: 0.05 | -0.66 | +0.06 | -1.26 | -0.78 |
formation_days=60, holding_days=20, threshold_pct=0, cost_bps=5 r-ts-momentum-us-sp500-0048 | cost_bps: 5 holding_days: 20 threshold_pct: 0 | -0.49 | -0.21 | -0.65 | -0.70 |
formation_days=60, holding_days=20, threshold_pct=0.1, cost_bps=5 r-ts-momentum-us-sp500-0052 | cost_bps: 5 holding_days: 20 threshold_pct: 0.1 | -0.38 | -0.05 | -0.66 | -0.43 |
formation_days=60, holding_days=60, threshold_pct=0.05, cost_bps=5 r-ts-momentum-us-sp500-0056 | cost_bps: 5 holding_days: 60 threshold_pct: 0.05 | -0.17 | -0.03 | -0.00 | -1.20 |
formation_days=120, holding_days=1, threshold_pct=0, cost_bps=5 r-ts-momentum-us-sp500-0060 | cost_bps: 5 holding_days: 1 threshold_pct: 0 | -0.69 | +0.11 | -1.43 | -1.12 |
formation_days=120, holding_days=1, threshold_pct=0, cost_bps=10 r-ts-momentum-us-sp500-0061 | cost_bps: 10 holding_days: 1 threshold_pct: 0 | -1.44 | -0.84 | -2.21 | -1.58 |
formation_days=120, holding_days=1, threshold_pct=0.1, cost_bps=10 r-ts-momentum-us-sp500-0065 | cost_bps: 10 holding_days: 1 threshold_pct: 0.1 | -0.84 | -0.03 | -1.79 | -0.99 |
formation_days=120, holding_days=5, threshold_pct=0.05, cost_bps=10 r-ts-momentum-us-sp500-0069 | cost_bps: 10 holding_days: 5 threshold_pct: 0.05 | -0.76 | -0.62 | -1.35 | +0.46 |
formation_days=120, holding_days=10, threshold_pct=0, cost_bps=10 r-ts-momentum-us-sp500-0073 | cost_bps: 10 holding_days: 10 threshold_pct: 0 | -1.19 | -0.49 | -1.97 | -1.29 |
formation_days=120, holding_days=10, threshold_pct=0.1, cost_bps=10 r-ts-momentum-us-sp500-0077 | cost_bps: 10 holding_days: 10 threshold_pct: 0.1 | -0.69 | +0.06 | -1.39 | -0.84 |
formation_days=120, holding_days=20, threshold_pct=0.05, cost_bps=10 r-ts-momentum-us-sp500-0081 | cost_bps: 10 holding_days: 20 threshold_pct: 0.05 | -0.49 | -0.33 | -0.56 | -0.74 |
formation_days=120, holding_days=60, threshold_pct=0, cost_bps=10 r-ts-momentum-us-sp500-0085 | cost_bps: 10 holding_days: 60 threshold_pct: 0 | +0.18 | +0.21 | +0.16 | +0.07 |
formation_days=120, holding_days=60, threshold_pct=0.1, cost_bps=10 r-ts-momentum-us-sp500-0089 | cost_bps: 10 holding_days: 60 threshold_pct: 0.1 | +0.21 | +0.22 | +0.24 | +0.06 |
formation_days=250, holding_days=1, threshold_pct=0, cost_bps=5 r-ts-momentum-us-sp500-0090 | cost_bps: 5 holding_days: 1 threshold_pct: 0 | -0.53 | -0.07 | -1.73 | +0.03 |
formation_days=250, holding_days=1, threshold_pct=0.1, cost_bps=5 r-ts-momentum-us-sp500-0094 | cost_bps: 5 holding_days: 1 threshold_pct: 0.1 | -0.51 | -0.11 | -1.24 | -0.34 |
formation_days=250, holding_days=5, threshold_pct=0.05, cost_bps=5 r-ts-momentum-us-sp500-0098 | cost_bps: 5 holding_days: 5 threshold_pct: 0.05 | -0.07 | -0.26 | -0.31 | +1.93 |