Value at risk(‘VaR’) It is a technique for estimating potential losses on risk positions as a result of movements in market rates and prices over a specified time horizon and to a given level of confidence. The use of VaR is integrated into market risk management and calculated for all trading positions regardless of how it is capitalised. The VaR model formulated by HSBC is predominantly based on historical simulation that incorporates the following features:
II. Non-Trading Portfolios
Basel III conditions to calculate VaR According to the Basel III framework the banks have flexibility in the calculation of their capital requirements, but there are some minimum standards which they have to adhere.
- Historical market rates and prices, which are calculated with reference to foreign exchange rates, commodity prices, interest rates, equity prices and the associated volatilities;
- Potential market movements utilised for VaR, which are calculated with reference to data from the past two years; and
- VaR measures, which are calculated to a 99% confidence level and use a one-day holding period.
- Trading portfolios; and
- Non-trading portfolios.
II. Non-Trading PortfoliosNon-trading VaR of the Group includes contributions from all global businesses. There was no commodity risk in the non-trading portfolios. The non-trading VaR ended the year lower compared with the previous year, due to a reduction in the non-trading interest rate VaR component. This was caused by the reduction of the risk in our investment portfolio, specifically from reduced interest rate risk on US Treasuries and agency mortgage backed securities.
Basel III conditions to calculate VaR According to the Basel III framework the banks have flexibility in the calculation of their capital requirements, but there are some minimum standards which they have to adhere. - The basis of the calculation is the VaR computed on a daily basis, using a 99th percentile, one tailed confidence interval.
- The 10-day-returns of the portfolio must be used, which can be approximated by using the 1-day-returns and scale them according to a normal distribution by √10 up to ten days.
- Furthermore, the length of the sample period underlying the calculation must be at least one year.
- Besides that the banks are free to choose between models based on variance-covariance matrices, historical simulations or Monte Carlo simulations.
- Moreover, the Basel III market risk framework defines a SVaR, which is calculated on the same basis as the VaR, but in a period of significant stress for the bank's portfolio.
- Use of historical data as a proxy for estimating future events may not encompass all potential events, particularly extreme ones.
- The use of a holding period assumes that all positions can be liquidated or the risks offset during that period, which may not fully reflect the market risk arising at times of severe illiquidity, when the holding period may be insufficient to liquidate or hedge all positions fully.
- The use of a 99% confidence level does not take into account losses that might occur beyond this level of confidence.
- VaR is calculated on the basis of exposures outstanding at the close of business and therefore does not necessarily reflect intra-day exposures.
- While calculating VaR of a portfolio, it is required to measure or estimate the correlations between the return and volatility of individual assets. With growing number and diversity of positions in the portfolio, the difficulty (and cost) of this task grows exponentially.
