VaR (Value at Risk)
A statistical measure used to estimate the maximum potential loss of a portfolio, asset, or financial position over a defined time horizon and at a specified confidence level. Value at Risk (VaR) provides a quantitative view of downside risk, making it a cornerstone of modern financial risk management.
VaR answers the question: “What is the worst expected loss over a given period under normal market conditions, at a certain confidence level?” For example, a one-day VaR of $1 million at 99% confidence implies there is a 1% chance the portfolio could lose more than $1 million in a single day.
There are three primary methods for calculating VaR:
- Historical Simulation – based on actual past market movements
- Variance-Covariance (Parametric) – assumes returns follow a normal distribution
- Monte Carlo Simulation – uses random market scenarios to estimate potential outcomes
For instance, a treasury team might use a 10-day VaR model at 95% confidence to assess the potential loss from holding foreign currency positions. If the model estimates a VaR of $500,000, the company expects with 95% confidence that losses will not exceed this amount over 10 days.
VaR is widely adopted by banks, asset managers, and corporates for risk assessment, regulatory reporting (e.g., Basel III), and internal limit setting. While it provides a concise risk snapshot, it does not predict extreme tail risks or identify the causes of potential losses, so it is often used in combination with tools like stress testing and scenario analysis.