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general Calculator Guide

How to use Cointegration Half-Life Solver

Engle-Granger residual ADF plus Ornstein-Uhlenbeck half-life from any two price or return series. The page reports hedge ratio, p-value, and a spread chart so you can size up the trade before sizing the trade.

By Orbyd Editorial · AI Fin Hub Team

What It Does

Use the calculator with intent

Engle-Granger residual ADF plus Ornstein-Uhlenbeck half-life from any two price or return series. The page reports hedge ratio, p-value, and a spread chart so you can size up the trade before sizing the trade.

Stat-arb traders evaluating a candidate pair before committing to a full backtest who need the quick cointegration + half-life answer.

Interpreting Results

ADF p-value below 0.05 means cointegrated. Half-life sets the holding period — 5-day half-life is daily-strategy territory, 50-day is monthly. Hedge ratio is the dollar weight per unit of the second series.

Input Steps

Field by field

  1. 1

    Upload data

    Upload two price series for the candidate pair. The tool will normalize and align timestamps.

  2. 2

    Run calculation

    Run the cointegration test (Engle-Granger ADF on residuals from the cointegrating regression). The tool refuses to estimate half-life if the test rejects.

  3. 3

    If

    If cointegration passes, the tool fits the OU mean-reversion process and reports half-life with standard error.

  4. 4

    Compare results

    Compare half-life across rolling windows (1-year, 3-year, full sample). Stable half-life across windows = robust pair; unstable = the relationship is regime-dependent.

  5. 5

    If

    If half-life is under 30 days and cointegration is stable, the pair is a candidate for further backtesting. Above 90 days, alpha decays before transaction costs amortize.

Common Scenarios

Use realistic starting points

Short half-life pair

Half-life

3 trading days

Daily strategy is viable; turnover is high so transaction costs matter; expect plenty of trade signals per month.

Long half-life pair

Half-life

60 trading days

Monthly strategy; signals rare but durable. Holding-period matches the half-life — closing early gives up most of the mean-reversion.

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FAQ

Questions people ask next

The short answers readers usually want after the first pass.

How long it takes for half of a cointegrated spread's deviation from equilibrium to mean-revert. From the Ornstein-Uhlenbeck speed-of-mean-reversion parameter θ: half-life = ln(2) / θ. Pairs with half-life under 30 days are typically tradeable; above 90 days, the alpha decays before round-trip costs are recovered.

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Planning estimates only — not financial, tax, or investment advice.