Explanation

Volatility-weighting is a technique used in historical simulation VaR where historical returns are adjusted to reflect current market volatility conditions.

Key points about volatility-weighting:

• Historic returns are adjusted: The historical returns are scaled by the ratio of current volatility to historical volatility
• VaR calculation procedure remains the same: After adjusting the historical returns, the VaR calculation follows the same procedure as standard historical simulation - the adjusted returns are sorted and the appropriate percentile is selected

Why other options are incorrect:

• Option A: While historic returns are adjusted, the VaR calculation procedure is NOT more complicated - it follows the same basic methodology
• Option C & D: Volatility-weighting adjusts HISTORIC returns, not current period returns

Mathematical representation: Adjusted return = Historical return × (Current volatility / Historical volatility)

This approach helps address the issue of changing volatility regimes in financial markets while maintaining the non-parametric nature of historical simulation.