What it is
The total risk exposure amount (TREA), commonly called risk-weighted assets (RWA), is the aggregate measure of an institution's exposures weighted by their riskiness. Assets and off-balance-sheet items are multiplied by risk weights reflecting their credit, market, operational, settlement and, where relevant, credit valuation adjustment risk. The resulting figure serves as the standard denominator for risk-based prudential ratios.
Ratios such as the Common Equity Tier 1 ratio, the total capital ratio and the risk-based component of MREL are all expressed as a percentage of TREA. A given nominal amount of capital therefore translates into a higher or lower ratio depending on the composition and risk weighting of the balance sheet.
How it works
Risk weights are determined either under the standardised approach, which applies prescribed weights by exposure class, or under internal ratings-based and internal model approaches, which allow banks to use supervised models subject to regulatory constraints. Operational risk and market risk contribute their own risk-weighted equivalents, which are added to credit risk to form the total.
Because the same capital base can produce different ratios depending on the denominator, TREA is a focus of supervisory scrutiny. Output floors, model approval and benchmarking exercises all aim to keep model-derived risk weights within credible bounds and to limit unwarranted variability across banks holding similar assets.
Legal basis
The total risk exposure amount is defined in the CRR, which specifies how the components for credit, counterparty, market, operational and settlement risk are calculated and summed. The capital ratios that use TREA as their denominator, and the buffer requirements layered on top, are set in the CRR and the CRD. MREL requirements expressed in risk-based terms reference the same measure.
Relevance for banks and investors
For banks, TREA is a central capital-planning variable. Reducing it, through de-risking, model changes or securitisation, raises capital ratios without new equity, while growth and risk migration increase it. The interaction between TREA and the combined buffer requirement determines the distance to the maximum distributable amount threshold.
For investors, TREA is essential context for interpreting headline ratios. Two banks with identical CET1 ratios can carry very different risk profiles if one uses conservative standardised weights and the other relies on low internal-model densities. Comparing capital and MREL positions across issuers requires looking through the ratio to the denominator that produced it.