Quantitative • Risk Modeling
Value at Risk (VaR) vs. Expected Shortfall (CVaR)
How quantitative desks calculate 99% VaR, the critical blindspot of traditional VaR, and Basel III Expected Shortfall fat-tail risk.
Author: CMD Wire Institutional Research
Updated: August 2026 • 6 min read
1. What Is Value at Risk (VaR)?
Value at Risk (VaR) is the standard institutional metric used by investment banks, hedge funds, and regulators to quantify the maximum potential dollar loss of a portfolio over a specific time horizon at a given statistical confidence level (typically 95% or 99%):
ext{A 1-Day 99% VaR of } \$10 ext{ Million means: there is a 1% chance the portfolio will lose more than } \$10 ext{ Million tomorrow.}
2. The Critical Blindspot of Traditional VaR
Traditional VaR has a dangerous theoretical limitation: it states the threshold of a loss, but says nothing about how catastrophic the loss will be once the threshold is breached (tail risk ignorance).
3. Expected Shortfall (CVaR / Tail VaR)
To fix this blindspot, modern risk desks and Basel III frameworks mandate Conditional Value at Risk (CVaR), also known as Expected Shortfall (ES):
Expected Shortfall calculates the average expected loss conditional on the loss exceeding the VaR cutoff point — accurately measuring fat-tail crisis risk during black-swan market events.