Research methodology
Most published market claims fail for the same handful of reasons: the test quietly used information that was not available at the time, the sample was chosen after the fact, costs were ignored, or the idea was one of hundreds tried and only the winner was reported. This page describes the sequence we use to catch those failures in our own work.
The sequence
Stages run in order. A stage cannot be skipped, and a refused attempt is recorded rather than discarded.
Step 1 — observe
Write down what was noticed, and when.
Step 2 — data qa
Check coverage, gaps, staleness and revisions before any test runs.
Step 3 — hypothesis
State the claim so that it can fail, together with the null it must beat.
Step 4 — strategy spec
Turn the claim into explicit machine-readable rules with bounded parameters.
Step 5 — code test
Implement the rules in deterministic code and test the code itself.
Step 6 — backtest
Measure the rules over history that the rules were allowed to see.
Step 7 — walk forward
Re-test in rolling sequence, fitting only on the past of each fold.
Step 8 — holdout
Test once against the reserved period, which was never used for tuning.
Step 9 — robustness
Perturb parameters, cut the sample, raise costs, and see what survives.
Step 10 — red team
Try to break the conclusion on purpose.
Step 11 — risk review
Review exposure, concentration and worst-case behaviour at portfolio level.
Step 12 — research report
Write the evidence packet: claims tied to sources and to specific test runs.
Step 13 — promotion proposal
Propose it to a person. A human signature is required; nothing promotes itself.
Anti-overfitting controls
- Point-in-time data. A signal formed on a given day may only use data visible on that day, and may only act on the following period.
- Locked holdout. A period of history is reserved and time-stamped before any tuning, and is never reused for tuning afterwards.
- Walk-forward testing. Rolling folds, each fitted only on its own past.
- Costs always on. Fees, spread and slippage are applied in every run, and every conclusion is re-checked with costs raised well above expectation.
- Counted attempts. The number of variants tested is recorded, and headline results are adjusted for the fact that repeated testing inflates them — the Deflated Sharpe and backtest-overfitting-probability diagnostics.
- Baselines. Nothing is judged in isolation. Buy-and-hold is always in the comparison.
What the red team tries to prove
A separate review stage is tasked with breaking the conclusion. Any one of these findings blocks a strategy outright, whatever its headline numbers.
Look-ahead bias
Does any feature use information dated at or after the label it predicts?
Data leakage
Could the target have influenced the features, directly or through a revision?
Survivorship bias
Does the universe include instruments that were removed during the test window?
Overfitting
Do the results depend on a narrow parameter neighbourhood?
Too many trials
How many configurations were tested before this one was reported?
Unstable parameters
Does performance collapse under small parameter perturbation?
Unrealistic fills
Are assumed fills achievable given the bar data and spread?
Liquidity and capacity
Could the position sizes be traded without moving the price?
Hidden concentration
Is the result driven by one instrument, sector or period?
Regime dependency
Does it only work in one detected regime?
Honest limitations
- Our current price history is short and drawn from our own logged readings. Short history limits confidence.
- We do not use paid vendor data, option chains or order-book data. Any claim needing them is out of scope.
- Everything runs in simulation. Simulated fills are optimistic compared with real execution at size.
- Surviving these tests makes a claim better evidenced. It does not make it true, and it guarantees nothing.
Research and education only; not investment advice or a recommendation to buy or sell any asset. Questions about the method are welcome: (800) 200-9553. Back to Market Intelligence.
