Outline the Basel stress testing principles that apply to banks when they put stress testing into practice.
The idea
The Basel stress testing principles for banks describe good practice in stress testing. Programmes should have clear, documented objectives and be an integral part of governance and risk culture, with board and senior management involvement. They should be enterprise-wide and cover material risks and business areas, including those hard to model, such as liquidity, concentrations and complex products. They should use a range of scenarios of varying severity, including forward-looking ones that go beyond history, take account of system-wide interactions and feedback effects, and challenge key assumptions. Reliable data and flexible information systems are needed to aggregate exposures. Results, with their assumptions and limitations, should be communicated to senior management and the board. These results should also be used in decisions on capital, liquidity, risk appetite and contingency planning. The programme must be documented, reviewed and updated regularly, with appropriate frequency.
A practice question
Which is consistent with the Basel principles for stress testing at banks?
- Stress testing should be limited to market risk in the trading book.Why not: Basel expects coverage of material risks across the bank, not only market risk.
- Stress testing should rely on a single worst-case historical scenario.Why not: Basel expects a range of scenarios, not a single historical case.
- Stress testing should be run at the same fixed frequency for all risk types and business lines in every year.Why not: Frequency should reflect the nature of the risk and purpose, not be uniform.
- Stress testing should have clear, documented objectives and be part of governance and risk culture. - correct
The principles start with clear objectives and integration into governance and risk culture, with board and senior management engagement.
A harder one
Which statement best reflects the Basel principle on scenarios?
- One severe scenario approved by the regulator is enough for the whole programme, as long as it is rerun every year.Why not: Basel expects a range of scenarios developed by the bank, not a single scenario.
- Banks should use a range of scenarios of differing severity, including forward-looking ones that go beyond past experience. - correct
- Scenarios should be drawn only from actual historical events.Why not: Basel expects scenarios that also look forward, not only historical events.
- Scenarios should be mild so that results stay close to expected conditions.Why not: Scenarios need to be severe enough to be informative.
Principles call for scenarios of varying severity, forward-looking and challenging, so that the bank does not simply replay the past.
The hardest tier
A bank's stress tests assume a constant balance sheet and ignore how other market participants would react to the same shock. Which Basel principle is most directly compromised?
- The requirement that stressed VaR uses a 250-day window.Why not: This is a regulatory VaR detail, not a Basel stress testing principle on feedback.
- The requirement that the bank's stress test results be disclosed to the public every quarter in full detail, including model parameters.Why not: Quarterly public disclosure is not what is at issue here.
- The requirement that every risk type be stress tested at the same frequency.Why not: There is no such uniform frequency requirement, and it is not relevant to the assumption described.
- The programme should capture system-wide interactions and feedback effects and challenge assumptions such as management actions. - correct
Basel stresses interactions and feedback effects (for example fire sales) and the testing of assumptions such as management action. A static balance sheet that ignores reactions fails that.
In the app: 6 practice questions on this outcome, spaced review that brings it back before you forget it.
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