Value at Risk (VAR or VaR)

Value at Risk  is a widely used measure of the risk of loss on a specific portfolio of financial assets.Value at risk  has been called the "new science of risk management" A technique used to estimate the probability of portfolio losses based on the statistical analysis of historical price trends and volatilities.VaR is able to measure risk while it happens and is an important consideration when firms make trading or hedging decision.

e.g. Let 0 be the current time. With value-at-risk, we summarize a portfolio's market risk by reporting some parameter of this distribution. For example, we might report the 90%-quantile of the portfolio's single-period USD loss. This is called one-day 90% USD VaR. If a portfolio has a one-day 90% USD VaR of, say, USD 5MM, it can be expected to lose more than USD 5MM on one trading day out of ten. This is illustrated in Exhibit 1.

Example: One-Day 90% USD VaR Exhibit 1

VaR has five main uses in finance: risk management, risk measurement, financial control, financial reporting and computing regulatory capital.A risk manager has two jobs: make people take more risk the 99% of the time it is safe to do so, and survive the other 1% of the time. VaR is the border.Common parameters for VaR are 1% and 5% probabilities and one day and two week horizons, although other combinations are in use.Although it virtually always represents a loss, VaR is conventionally reported as a positive number. A negative VaR would imply the portfolio has a high probability of making a profit, for example a one-day 5% VaR of negative $1 million implies the portfolio has a 95% chance of making $1 million or more over the next day.

To sum up,Value-at-Risk (VaR) measures the worst expected loss under normal market conditions over a specific time interval at a given confidence level.It has 3 main components e.g.

• What is the most I can - with a 95% or 99% level of confidence -  expect to lose in dollars over the next month?
• What is the maximum percentage I can - with 95% or 99% confidence - expect to lose over the next year?

"VAR question" has three elements: a relatively high level of confidence (typically either 95% or 99%), a time period (a day, a month or a year) and an estimate of investment loss (expressed either in dollar or percentage terms).