Systemic risk buffer

The systemic risk buffer (SyRB) is a layer of Common Equity Tier 1 (CET1) capital that regulators require banks to hold on top of minimum capital requirements, designed to mitigate structural systemic risks in the financial system. In the European Union it is codified in the Capital Requirements Directive (CRD IV, and as amended by CRD V in 2019), which allows designated national authorities to set the buffer for all banks, a subset of banks, or specific exposures.

Unlike the countercyclical capital buffer, which moves with the credit cycle, the SyRB targets risks that are long-term and structural — for example, concentration in real estate lending, exposure to a few large corporates, reliance on foreign funding, or the dominance of a small number of institutions in a national banking sector. It is distinct from the buffers for global systemically important institutions (G-SIIs) and other systemically important institutions (O-SIIs), though under CRD V it can be combined with them subject to procedural thresholds (above 5% combined, the authority must seek European Commission authorisation).

National practice varies widely. The Czech National Bank, Norges Bank, the Estonian and Croatian central banks, and the Dutch and Danish authorities have all activated SyRBs at different rates, often between 1% and 3% of risk-weighted assets. Following the CRD V reforms, authorities can apply a sectoral SyRB targeting specific exposure classes — for instance, residential mortgages — rather than the whole balance sheet. Belgium and Germany adopted this approach for housing-loan exposures in the early 2020s.

The buffer must be met with CET1 capital. Breaching it triggers automatic restrictions on dividends, bonuses, and Additional Tier 1 coupon payments under the Maximum Distributable Amount (MDA) framework. The SyRB is a core tool in the post-2008 macroprudential toolkit alongside Basel III standards.