Open Research / Observable Evidence / Proprietary Implementation

Trust Center

Do not ask for trust. Build for verification.

Research Philosophy

Don’t trust the backtest. Check what happened after it. Research should be open enough to be challenged. Evidence should be open enough to be examined.

Overfitting Validation Framework

Core Backtest Validation

The minimum checks we run on every backtest before a strategy is considered.

A1. Massive Grid Search

We search a wide parameter space and look for a plateau where results hold up, not a single best point.

A2. Parameter-Space Robustness

We compute beta-adjusted alpha for every grid pattern and report the share of patterns with positive alpha, not just the champion.

A3. In-Sample / Out-of-Sample

Selection uses only data up to a cutoff; evaluation uses the unseen period after it.

A4. Multi-Window Walk-Forward

We repeat select-then-evaluate as time moves forward, across several in-sample window lengths, so one lucky window cannot carry the result.

A5. Beta-Adjusted Alpha

We estimate market beta and evaluate what remains after market exposure is removed; strategies can and do fail this step.

A6. Expanding Window

We also test with an expanding training window, so results do not depend on one rolling window length.

A7. Regime Robustness

We break results down by market regime instead of relying on a single average.

A8. Vintage OOS

We rerun the research as if we stood at an earlier date, using only information available then, and evaluate what followed.

A9. Reject / Adopt

Strategies that pass early tests are still rejected when later tests fail; rejected research is kept on record.

A10. Real Prospective Forward

After every backtest check, the researcher still knows the past; only signals published in advance and observed afterward remove that.

Advanced DM-Signal Robustness Tests

Additional tests specific to DM-Signal, beyond the core checks above.

1. Alpha Space Check

Measures the CAGR positive-rate across the entire parameter space. Broadly positive results across the parameter space reduce the likelihood that performance comes from a single isolated parameter spike, but do not by themselves rule out overfitting.

source: context/robustness-verification-catalog.md §0

2. Decay Analysis

Directly measures whether a champion selected in the past has eroded over time, using p_det_roll/p_erosion across 6/12/24-month windows.

source: context/robustness-verification-catalog.md §4.1

3. Vintage Analysis

Verifies whether out-of-sample performance reproduces across champions selected at different points in time, using selection timelines and IS/OOS comparison.

source: context/robustness-verification-catalog.md §4.2

4. Parameter Neighborhood Analysis

Confirms whether a champion is an isolated spike or a broad peak, by comparing the performance drop-off across neighboring parameters.

source: context/robustness-verification-catalog.md §4.3

5. Stress Test

Examines whether the apparent edge holds up against the benchmark during extreme periods such as sharp drawdowns or rate-hike shocks.

source: context/robustness-verification-catalog.md §4.4

6. Fold Percentile Verification

Confirms whether a fixed champion maintains better-than-random performance within each walk-forward fold's population, via fold percentile.

source: context/robustness-verification-catalog.md §4.5

7. Metric Top-Stability

Measures how well the top set is preserved as the calculation window is shortened, using overlap rate / Jaccard similarity.

source: context/robustness-verification-catalog.md §4.6

8. Regime-Conditional Verification

Checks whether alpha remains positive across Bull/Bear/Sideways regimes, exposing apparent strength that depends on a single market condition.

source: context/robustness-verification-catalog.md §4.7

9. Rule Freeze

Locks selection rules and parameters at a fixed point in time, with no undocumented changes afterward. This freeze point becomes the boundary against the still-unverified future.

source: Rule Freeze

10. Forward Observation

Observes and recalculates only real-time results after the Rule Freeze, kept distinct from the backtest. Forward metrics are computed using only rows from the forward period.

source: Forward observation

Prospective Forward Policy

Everything before the line is still history. Selection rules are frozen (Rule Freeze), and only results observed after that freeze count as forward, real-time evidence. Forward metrics are recalculated using forward-period rows only.

Signal Archive Policy

  1. Published signals are historical records of what was actually displayed at that time.
  2. If a signal publication was wrong due to an operational error, preserve the original and append a correction with timestamp and reason.
  3. Historical market data may be corrected later. Recalculated research series may therefore differ from the original historical signal record.
  4. Data corrections do not justify rewriting the old publication record.
  5. Methodology changes receive a new version and effective date.
  6. Bug fixes are distinguished from research improvements.
  7. All user-facing performance pages should link to the relevant revision policy.

Historical Data Revision Policy

Historical market data may be corrected later by data vendors; recalculated research series may therefore differ from the original historical signal record. Data corrections do not justify rewriting the old publication record.

Detailed, per-event revision log: in preparation.

Deterministic Selection / Numerical Stability

Portfolio selection is deterministic: the same inputs always produce the same selection. Candidates whose scores fall within a small tolerance band are treated as tied, and ties are broken by a fixed, economically meaningful sequence, so tiny numerical noise cannot flip the ranking. The internal tie-break keys and weighting rules are not published.

Methodology Version History

Methodology version history is in preparation.

Research Log

Research log (adopted / rejected / under test / deprecated) is in preparation.

Data Sources

Price data: Yahoo Finance daily prices (via yfinance), with in-house split and dividend adjustment checks. Daily closes are cross-checked against EODHD and Tiingo. Risk-free rate: 3-month U.S. Treasury bill (DTB3). Benchmark: SPY. System of record for signals and returns: PostgreSQL.

External References

DM-Signal uses a separation between public research and member-only implementation similar to AQR's — not equivalent to AQR.

Disclaimer

DM-Signal publishes systematic research and rules-based signals for informational purposes. Past performance, including forward-only results, does not guarantee future results. Nothing on this page is investment advice.