The Value-at-Risk (VaR) method simplifies the risk measurement process by mapping positions on selected risk factors. This approach is used because it is impractical and overly complex to model all positions individually as risk factors. Instead, the VaR method identifies key risk factors and maps the positions of the portfolio onto these. This allows for a more manageable and efficient risk measurement process. The selected risk factors are those that are deemed to have the most significant impact on the performance of the trading instruments and portfolios. Therefore, not all risk factors are considered; only those that are most relevant and impactful. This makes the VaR method a practical and effective tool for risk measurement in the financial sector.

Choice B is incorrect. While it's true that risk factors can have a minor or major impact on the performance of an instrument, mapping positions on all risk factors would be impractical and time-consuming. The purpose of mapping in the context of VaR is to simplify the process by focusing on selected risk factors.

Choice C is incorrect. Mapping positions based only on five risk factors would not necessarily provide a comprehensive view of the portfolio’s risk characteristics. The number of risk factors to consider depends on the complexity and nature of the portfolio, not a fixed number.

Choice D is incorrect. Mapping positions based solely on abnormal risk factors could overlook normal but significant risks that could impact the performance of an instrument. Therefore, this approach does not accurately reflect the purpose of mapping in the VaR method, which aims at simplifying the portfolio by focusing on selected key risks.

Things to Remember

• Value-at-Risk (VaR) is a widely used risk measurement method in the financial sector to quantify the potential loss in value of a portfolio over a specific time horizon under normal market conditions.