How Value at Risk Is Used Alongside Other Risk Measures

Article Quant Q&A · Author: A H

Summary

The document addresses whether value at risk remains useful despite shortcomings in how it is sometimes interpreted and its failure to satisfy coherence. It explains that financial institutions use VaR as one component of risk management, often with models tailored to their portfolios and purposes rather than a simple normal-distribution calculation. The measure can support reporting, business decisions, and counterparty assessments, including setting position limits after a broker reviews a prospective client’s holdings.

VaR is not presented as a standalone description of risk. Risk teams combine it with sensitivities and stress scenarios to assess positions at desk, strategy, account, or firm level. Although an absolute VaR figure may be difficult to interpret, comparisons across time or organizational levels can help reveal changes in measured risk. The examples are qualitative and do not specify a VaR horizon, confidence level, model design, or the details of liquidity adjustments. They illustrate institutional uses rather than demonstrate that VaR is sufficient for comparing portfolios or capturing losses beyond its threshold.

Key ideas

Financial institutions use VaR as one input to risk management and reporting.
Practical VaR models may be tailored to a firm’s positions and intended decisions.
Brokers can use portfolio risk estimates when assessing counterparty exposure and position limits.
Risk teams combine VaR with sensitivity measures and stress scenarios.
Changes in VaR can help track risk over time, though the measure is not a complete risk picture.

Tags

Risk management Statistics

Full text

# Do people actually use VaR in professional settings?

VaR seems like such an obviously flawed metric, I am surprised that it seems to be used so much in the private sector.

First, the way it is named and the way it is presented often imply it is the expected value of loss, when in fact it is the upper bound on loss. It seems risk measures should be conservative, and presenting the upper bound, is the opposite of conservative.

More seriously, the fact that VaR is not coherent means that you can't use it to compare two portfolios, or even compare a changing portfolio over time. Doesn't this make value at risk completly useless?

I am just starting out in quant finance, so this is a presumptious question, and I am probably missing something. Thanks for any hlep.

## Answer by madilyn (score 6)

https://quant.stackexchange.com/a/15092

As discussed, banks do use VaR for risk management. They will have something modified for the specific use (i.e. probably not your VaR from a fitted normal distribution), it's likely more sophisticated but the underlying idea is the same. VaR is used for reporting/ceremonial business decisions as much as (or perhaps even more than) it is for trading decisions. I'm outdated on this, but I believe liquidity risk is also becoming an important priority in the Dodd-Frank/Basel III environment, and liquidity adjustments to VaR is probably one of the cool and exciting things to be doing in that space.

On the buy-side, the easiest example that comes to mind is when a trading entity (hedge fund, prop firm etc.) opens a brokerage account. In addition to typical due diligence questions and background about your expected overnight inventory, the brokerage firm will ask you to submit a 'sample portfolio'. That's really just a snapshot of the range of possible position sizes so that they can put that into their risk/compliance department's VaR model and figure out what kind of counterparty risk you'll pose to their overall firm and what kind of position limits to impose on you.

## Answer by Paul P M (score 0)

https://quant.stackexchange.com/a/15160

It is but one of the methods used by risk management to gauge the level of risk undertaken at desk/strategy/account/office/firm etc., levels. Others are risk sensitivities and stress scenarios. All are usually used together to get an overall picture of the risk position and used to make decisions. Even though the absolute VaR value might seem a bit obscure the relative VaR value can be more intuitive and useful to see how risk is changing by the levels given above.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.