Despite declining financial market volatility during recent years, most large banks have nevertheless reported a trend rise in the aggregate VaR of their trading book. This presumably implies that they have taken larger positions. This is not necessarily a matter of concern because trading profits and capital increased broadly in line with higher VaRs.
Although the national supervisory authorities are providing us with assistance, the final review is always performed centrally by the ECB, to ensure that all the results are comparable. It is important that the central bank has ultimate discretion and power, so that national discretionary margins can be reconciled. A similar rationale applies to the interaction between the assessed banks and the supervisor.