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Hedge Ratio Calculator

Calculate the optimal hedge ratio, optimal number of futures contracts, and hedged portfolio value using spot & futures price volatilities and correlation.

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Understanding Hedge Ratio in Financial Risk Management

The hedge ratio compares the value of a hedged position (such as futures or options contracts) against the total exposure of the underlying asset or portfolio. It measures the proportion of an asset or liability that is protected against adverse price movements.

The Optimal (Minimum Variance) Hedge Ratio Formula

In financial derivatives theory, the minimum variance optimal hedge ratio ($h^*$) minimizes the variance of the combined hedged portfolio value. It is calculated as:

$$h^* = \rho \times \left(\frac{\sigma_s}{\sigma_f}\right)$$

Where:

  • $\rho$: Correlation coefficient between changes in spot price ($\Delta S$) and futures price ($\Delta F$).
  • $\sigma_s$: Standard deviation of changes in spot price.
  • $\sigma_f$: Standard deviation of changes in futures price.

Optimal Number of Futures Contracts

Once the optimal hedge ratio is calculated, the exact number of futures contracts ($N^*$) needed to hedge a portfolio value $V_A$ with contract value $V_F$ is:

$$N^* = h^* \times \left(\frac{V_A}{V_F}\right)$$

Frequently Asked Questions

What does a hedge ratio of 1.0 mean?

A hedge ratio of 1.0 (or 100%) means the position is fully covered (perfect hedge). The value of the hedging instrument equals the value of the underlying asset.

What is basis risk in hedging?

Basis risk occurs when spot prices and futures prices do not move perfectly together ($\rho < 1$). The optimal hedge ratio adjusts for correlation and volatility differences to minimize basis risk.

Can the optimal hedge ratio exceed 1.0?

Yes. If spot price volatility is significantly higher than futures price volatility ($\sigma_s > \sigma_f$) and correlation is high, $h^*$ can be greater than 1.0.