Question

What difference does volatility scaling make on estimating the VaR and expected shortfall when we use historical simulation?

Answer 1

generally use of VaR is to measure any kind of loss that may occur (risk) on investments or buying any property.

but when we take historical stimulation , one need to see length of historical period and the structure of shocks with their hetroscedendicity in the risk factrs in the simple case.

but if you consider volatlity scaling on estimating the VaR (value at risk) using historical stimulation , one needs to rescale the past observation of risk factors to account for volatility dynamics during the estimation period.

this kind of study is more used to check back testing of properties with increase in price and its cycle.