Read the number and its rule together
For this positive upper limit,
Here is the rule behind that snapshot. These choices belong to the fictional firm; another organisation may use different approvals and responses.
| Policy field | Fictional desk rule |
|---|---|
| Scope and measurement basis | All positions in this desk's book, valued at the daily close in USD using the approved one-day 95% VaR model. Additional intraday checks follow material position changes. |
| Ceiling | Measured VaR must be no greater than USD 1 million; equality is permitted by this policy. |
| Warning | At or above USD 0.9 million, including equality, notify the desk head and independent market-risk manager for review before adding risk. This warning does not itself change the ceiling. |
| Approval authority | The risk committee approves the limit and any permanent change. The desk cannot raise its own allowance. |
| Monitoring responsibility | Independent market risk checks positions and model inputs, records utilisation and reports exceptions. The desk head remains responsible for operating within the mandate. |
| Escalation | Above the ceiling, record a limit breach, notify the head of risk promptly and suspend additions to risk pending a decision. A temporary exception needs the authority specified in the firm's delegation; otherwise it goes to the committee. Record the reason, expiry and corrective action. |
The current USD 0.8 million reading is below both the warning and the ceiling. That statement is narrower than “the portfolio is safe.”
A limit is not a promise about losses
The measured VaR is a model's estimate of a loss quantile. The limit is management's boundary for that estimate. Neither makes USD 1 million the maximum possible next-day loss. Losses can exceed VaR, and model or data errors can make the estimate misleading. A quiet market can lower estimated VaR without removing concentrated positions, poor market liquidity or funding needs.
This is why a VaR allowance may sit alongside stress testing, concentration controls and liquidity limits. Passing one test does not imply passing the others. Nor can desk-level VaRs simply be added and labelled the firm's VaR: aggregation depends on the joint loss behaviour, and VaR is not generally subadditive.
Limits can also bind in different directions. A minimum liquidity requirement has a floor, while a factor exposure may have both an upper and a lower bound. The utilisation formula above is for a positive upper ceiling; it should not be copied blindly to signed exposures or minimum requirements.
A profitable outcome does not erase an unauthorised breach. Likewise, formally raising a limit changes what is permitted; it does not itself reduce the portfolio's economic risk. A useful limit therefore has a defined metric, a reliable measurement process and a decision-maker who can respond when the boundary is approached or crossed.
Sources
- Financial Stability Board, Principles for an Effective Risk Appetite Framework, 18 November 2013, Section II and Section III.3–4, printed pp. 2 and 6–10: relationship between appetite and limits, monitoring and assigned responsibilities.
- John C. Hull, Risk Management and Financial Institutions, 4th edition, Wiley, 2015, Section 12.1, pp. 255–257; Section 12.3, p. 259; Section 12.5, pp. 260–261; and Section 28.1, pp. 577–579: VaR's horizon, confidence level, tail blindness and aggregation; clear limits, monitoring and breaches that produce profits. The desk, thresholds and workflow above are original fictional examples.