Definition
Value at Risk (VaR) estimates the maximum potential loss of a portfolio over a specified time period at a given confidence level. For example, a one-day 95% VaR of $1 million means there's a 5% chance of losing more than $1 million in a day. VaR is widely used by financial institutions for risk management and regulatory capital requirements. While useful, VaR has limitations - it doesn't measure losses beyond the confidence level and can underestimate tail risks.
Formula
Example
A $10 million portfolio with daily volatility of 2% has a 95% one-day VaR of approximately $330,000 (10M x 1.65 x 0.02). This means on 95% of days, losses won't exceed $330,000.
FAQ
What is Value at Risk (VaR)?
The maximum expected loss over a time period at a given confidence level.
How do you calculate Value at Risk (VaR)?
A common formula for Value at Risk (VaR) is: VaR = 投资组合价值 x z分数 x 标准差 x 根号t（参数法）; 其中z = 1.65（95%置信度），2.33（99%置信度）
Why is Value at Risk (VaR) important?
Value at Risk (VaR) helps investors evaluate risk metrics and make more informed decisions.