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Pairs trading & cointegration (ETFs) · 2026-08-31

Copula Mispricing-Index Pairs

trade the conditional-probability signal instead of a linear spread

expected Sharpe 0.5–1.0confidence: mediumfree daily data

ETF pairs are often only weakly volatile, so linear-spread cointegration yields few signals; a copula separates marginals from the dependence structure and produces a "mispricing index" from conditional probabilities, capturing nonlinear and tail dependence and generating more (and different) trades. This is a fundamentally different signal from any prior linear z-score or PCA-residual idea.

Universe

ETF pairs with high Spearman rank correlation but modest linear spread volatility, e.g. broad sector/style ETF pairs; fit marginals from daily returns.

How it works

Fit marginal CDFs and a (mixed) copula on a formation window; compute the two conditional mispricing indices, enter when the cumulative mispricing index crosses upper/lower flags (e.g. 0.05/0.95), exit on return to 0.5, dollar-neutral equal legs.

Expected performance

Research-derived Sharpe estimate: 0.5–1.0. copula variants reported to beat the distance method with more consistent post-2009 performance, but net-of-cost gains are modest).

Backtest this idea with SignalChain

This is a research lead — not a finished backtest. SignalChain takes an idea like this and runs the whole pipeline inside Claude Code: it researches the concept against academic and practitioner sources, sets benchmarks, writes and lints a VectorBT backtest, runs it, and grades the result PASS/FAIL. One command:

/signalchain Copula-based pairs trading using mixed-copula mispricing index on rank-correlated ETF pairs, enter at 0.05/0.95 flags, exit at 0.5, dollar-neutral Get SignalChain — $49 →

Research & sources

Not financial advice. This page describes a research idea, not a recommendation. Any performance figures are hypothetical, research-derived estimates and are not indicative of future results. SignalChain is a research and educational tool; you are solely responsible for any decisions you make.