Executive result
A real gross effect. An untradeable net result.
Residual dislocations revert often enough to produce a positive gross signal. The problem is economic, not cosmetic: capturing it requires so much trading that the result crosses below zero between 0 and 2 basis points per unit of turnover.
Decision: close this 15-minute PCA-residual branch and move to funding carry. No isolated best configuration is allowed to overrule the pre-registered median-of-grid criterion.
Research question
Can relative mispricing survive after common crypto risk is removed?
The market often moves as one large risk complex. A token can rise while still underperforming what its exposure to the common market factors would imply. The study asks whether that idiosyncratic gap subsequently converges strongly enough to trade.
The object that converges
Not a bilateral pair. It is each asset’s cumulative return residual after projecting out a small set of rolling PCA factors.
The economic bet
Buy unusually negative residuals and sell unusually positive residuals while constraining the portfolio’s common-factor exposure.
The falsification test
The broad grid—not its maximum—must remain positive after 3.5 bps per unit of turnover and across time.
“A backtest is useful when it can kill an attractive story before capital has to.”
Experimental design
One chronological research programme, two stages
Version 1.0 established whether the phenomenon existed. Version 1.1 tested the cheapest plausible fixes to the turnover problem without changing the hypothesis after seeing the answer.
Observe
50 liquid USDT perpetuals, aligned 15-minute opens.
Neutralize
Estimate rolling PCA factors and isolate residual returns out of sample.
Standardize
Accumulate residuals and map their deviation to an OU-style score.
Construct
Contrarian, factor-neutral weights with explicit portfolio turnover.
Falsify
Stress costs, time periods and a pre-defined continuation grid.
Method
From prices to a neutral residual portfolio
The method is deliberately linear and interpretable. Each transformation has a specific job and can be inspected independently.
Convert open prices to log returns
Missing or structurally stale instruments are excluded from the relevant rolling estimate rather than filled with invented returns.
Estimate common factors on a rolling window
PCA is applied to the correlation matrix, preventing high-volatility assets from mechanically dominating. Marchenko–Pastur is used as a diagnostic of how many eigenvalues rise above a noise benchmark.
Generate out-of-sample residual returns
Loadings are frozen between refreshes. The next block is transformed with parameters estimated only from prior observations, avoiding look-ahead.
Build and score the residual state
The accumulated residual is evaluated with an AR(1)/Ornstein–Uhlenbeck representation. Entry thresholds select unusually displaced states; the position is contrarian.
Neutralize and charge the actual portfolio movement
Factor legs are netted at portfolio level. Costs are charged on final-weight turnover; the same factor hedge is never counted twice.
Why the PCA regression can be simplified exactly
Risk and performance statistics
Stage I · Baseline v1.0
The first grid found signal—and immediately exposed its fragility
The 81-configuration grid crossed three PCA windows, three factor counts, three residual horizons and three entry thresholds. It asked whether a broad region of the model behaved well, not which single row looked best.
| Dimension | Values | Purpose |
|---|---|---|
| PCA lookback | 20 / 30 / 60 days | Factor stability versus adaptation |
| Factors K | 2 / 3 / 5 | Amount of common variation removed |
| Residual horizon | 7 / 14 / 30 days | State and OU estimation horizon |
| Entry score | 1.5 / 2.0 / 2.5 | Trade frequency versus extremeness |
Diagnosis, not conclusion: residual reversion appears in gross returns, but concentration reached roughly 50% in one asset and turnover was extreme. That justified one bounded continuation—not indefinite parameter rescue.
Stage II · Continuation v1.1
Four levers were allowed. Each had a reason and a stopping rule.
The continuation was specified before execution. Cheap interventions stayed within the hypothesis; lower-frequency reformulations and explicit BTC factors were classified as new projects, not post-hoc repairs.
A · Weight caps
Cap each asset at 10%, 20% or 35% to attack the 50% concentration observed in the baseline.
B1/B2/B3 · Trading inertia
Wider entry/exit hysteresis, a no-trade deadband and action every 1, 2, 4 or 8 bars.
B4 · Turnover penalty
Penalize movement inside portfolio construction instead of projecting first and paying later.
C · Residual-quality filters
Trade only the top 75%, 50% or 25% of residual series by AR(1) fit quality.
Frozen final recipe
No cap; entry 3; exit 0; 0.2 deadband; act every 8 bars; no movement penalty; all eligible residuals.
Robustness
The answer must survive configuration choice, trading intensity and time
A credible research decision cannot depend on one backtest curve. The final assessment uses a 27-configuration grid, a turnover frontier and time-sliced validation.
| Cost | Median Sharpe | Positive grid | Interpretation |
|---|---|---|---|
| 0 bps | 0.358 | 74.1% | Statistical phenomenon exists gross |
| 2.0 bps | ≈ 0.020 | 51.9% | Economic edge nearly exhausted |
| 3.5 bps | −0.213 | 33.3% | Locked acceptance test fails |
Conclusion
What this study proves—and what it does not
The negative decision is the product. It preserves research capital and narrows the next question.
Supported by the evidence
- PCA residual dislocations contain measurable short-horizon mean reversion.
- The gross effect is broad across the final grid.
- Slower action and stronger thresholds reduce turnover.
- At the chosen market-friction assumption, the 15-minute implementation is not robustly profitable.
Not established
- That residual reversion is absent at 1-hour or 4-hour horizons.
- That an explicit BTC or sector factor model cannot improve residual quality.
- That order-book execution would recover the missing economics.
- That the result transfers unchanged to another exchange, universe or fee tier.
Next branch: funding and basis carry, where the convergence anchor is mechanical and turnover is naturally lower. Slow residual models remain separate new hypotheses, not a continuation of this grid.
Open research package
Reproduce the pipeline without redistributing exchange data
The repository contains research code, locked configurations, figure generation and methodological documentation. Raw OKX candles are deliberately excluded; the data guide explains how to obtain and transform them.
Public repository
Clone the project, follow the data contract, run the baseline and continuation, then regenerate every figure from the aggregated artifacts.
Data and sources
Provenance and transformations
Instruments were identified from OKX’s public swap catalogue, and candles came from its official historical-candles endpoint. Snapshot end: 27 August 2026, 23:45 UTC.
- OKX: public instruments (SWAP)
- OKX: historical market candles
- Data contract and preparation
- Citation and version metadata
The study uses the first open of each 15-minute interval, built from 1-minute opens. Raw exchange data are not redistributed; the public repository retains the code, configuration, and aggregated artifacts.
1 · Acquire
Download 1-minute OKX perpetual candles and aggregate each 15-minute bar with the first open.
2 · Research
Run the time-causal factor-residual pipeline using the committed parameter registry.
3 · Audit
Compare the grid medians, positive fractions and subperiod metrics—not just the maximum Sharpe.