In accordance with the National Bank Act, the SNB contributes to the stability of the financial system. It fulfils this mandate by analysing sources of risk to the financial system and identifying areas where action is needed. The SNB also participates at international level, in particular in connection with the efforts of the Basel Committee to create and implement a regulatory framework for the financial centre. In addition, the SNB designates systemically important banks and performs tasks in the macroprudential area. It also oversees systemically important financial market infrastructures which can pose a risk for financial stability. In the event of a crisis, the SNB fulfils its mandate by acting as lender of last resort where necessary.

The SNB publishes its assessment of Swiss banking industry stability in its annual Financial Stability Report. In this report, the SNB focuses on trends that are observable at the levels of the banking system, the financial markets and the macroeconomic environment. The main purpose of the report for the SNB is to draw attention to tensions or imbalances which could pose a threat to system stability in the short or long term. In addition, it identifies areas where action may be needed to reduce this risk. In the report, the SNB analyses the situation at both the globally active Swiss big banks and the domestically focused commercial banks. It also frequently comments on current developments in the area of financial stability in its speeches and presentations.

The objective of macroprudential measures is to increase the stability of the financial system. First, they strengthen the resilience of the financial system to shocks. Second, they counter the build-up of systemic risk. Macroprudential measures not only target individual financial market participants but the Swiss banking sector as a whole. The countercyclical capital buffer is an important example of a macroprudential measure, as are the special requirements for systemically important banks.

The countercyclical capital buffer is an instrument through which the Federal Council can require the banks to hold additional capital as a precaution. On the one hand, the capital buffer is intended to strengthen the banks' resilience to risks emanating from excessive credit growth. On the other hand, it helps curb excessive credit growth. The capital buffer can be targeted at the entire credit market or just parts thereof, e.g. the mortgage market. The measure has been available in Switzerland since July 2012. The capital buffer is set at a maximum level of 2.5% of a bank's total domestic risk-weighted assets. If it is activated, banks are required to carry out a temporary and gradual capital increase.

If the SNB comes to the conclusion that an activation, adjustment or deactivation of the buffer is required, it makes a proposal to the Federal Council after consultation with the Swiss Financial Market Supervisory Authority (FINMA, www.finma.ch). In February 2013, at the proposal of the SNB, the Federal Council decided to activate the countercyclical capital buffer for the mortgage market for the first time (press release). In January 2014, the Federal Council approved the SNB's proposal to increase the capital buffer (press release).

Domestically focused banks have a particularly high proportion of mortgage loans. Therefore, excesses on the real estate market can present not only borrowers but also banks with considerable problems. Against this background, the mortgage and real estate markets constitute a potential source of risk for financial stability. Indeed, experience in Switzerland and abroad has shown that real estate crises can have a very detrimental impact on the financial system und ultimately the entire economy. This is why the SNB monitors developments in the mortgage and real estate markets closely and also participates in regulatory measures aimed at reducing the associated risks.

To reduce the risks on the Swiss mortgage and real estate markets, the capital requirements for mortgage lending with a high loan-to-value ratio have been tightened and the banks' self-regulation rules for granting mortgage loans revised. Should there be a further build-up of imbalances on the Swiss mortgage and real estate markets, additional measures might be necessary.

Issued by the Basel Committee for Banking Supervision, a permanent committee of the Bank for International Settlements (BIS, www.bis.org), the Basel Capital Adequacy Framework has the purpose of increasing the stability of the international financial system and promoting a level playing field in competition among banks. The original Basel Capital Framework (Basel I), which focused on the provision of minimum cover for credit risks, was issued in 1988. In 1996, capital requirements for market risk were added.

The first revised framework (Basel II) was adopted in 2004. On the one hand, capital adequacy requirements were extended to include operational risks and were made more sensitive to risk in general. On the other hand, the minimum capital requirements were supplemented by two further pillars, one relating to the supervisory review process and the other to disclosure obligations for the purpose of strengthening market discipline.

The second revised framework (Basel III) was adopted in the wake of the global financial crisis of 2008 and implemented in two stages. In a first step, stricter, countercyclical, risk-based capital requirements as well as limits on leverage (unweighted capital ratios, leverage ratio) were approved in 2010. In addition, internationally harmonised minimum liquidity requirements were introduced, consisting of the short-term liquidity coverage ratio and the net stable funding ratio (structural liquidity ratio).

The Basel Committee finalised the second stage in 2017. The aim of these more recent measures is to restore the credibility of risk-weighted requirements. To this end, the Committee restricted the use of internal bank models and improved the risk sensitivity of the prescribed standardised approaches. In addition, it recalibrated the floor for model-based requirements, setting it at 72.5% of the requirements under the standardised approaches. The changes will enter into force on 1 January 2022, with a five-year transition period before the floor for the model-based requirements applies in full.

Under the terms of the Federal Act on Banks and Savings Banks (Banking Act, www.admin.ch, in German, French and Italian), a bank or group of banks is systemically important if its failure would cause serious damage to the Swiss economy and the Swiss financial system. In assessing the systemic importance of banks or bank groups, their market share in domestic loan and deposit-taking business is an important criterion. Other criteria such as size, risk profile and interconnectedness are also taken into consideration when deciding on systemic importance. The Banking Act gives the SNB the authority, in the context of the implementation of 'too big to fail' regulations, to designate banks and bank functions as systemically important. FINMA and the systemically important bank concerned must be consulted in advance. As at the end of 2016, Credit Suisse, UBS, Zürcher Kantonalbank, the Raiffeisen Group and PostFinance Ltd. were considered systemically important (Press releases, decrees issued by the SNB).

The 'too big to fail' regulations impose special requirements on systemically important banks. They are laid down in the Banking Act, the Ordinance on Banks and Savings Banks (Banking Ordinance, www.admin.ch, in German, French and Italian) the Ordinance on Capital Adequacy and Risk Diversification for Banks and Securities Dealers (Capital Adequacy Ordinance, CAO, www.admin.ch, in German, French and Italian) and the Ordinance on the Liquidity of Banks (Liquidity Ordinance, www.admin.ch, in German, French and Italian). The regulations are designed to resolve the 'too big to fail' issue in Switzerland so that systemically important banks do not have to be bailed out with taxpayers' money in the event of a crisis. The TBTF regulations include provisions in the areas of capital, liquidity, risk diversification and organisation. They comprise measures which should make it easier to ensure the resolution of a systemically important bank in a crisis. The Swiss regulations are in line with international requirements by the Financial Stability Board (FSB, www.fsb.org), an international body which brings together finance ministries, regulatory authorities, central banks and the Basel Committee for Banking Supervision.

In the event of a crisis, the SNB can act as lender of last resort. Under the emergency liquidity assistance arrangements (Guidelines on monetary policy instruments), it can provide one or several domestic banks with liquidity if they are no longer able to refinance their operations on the market. Emergency liquidity assistance is provided only if the bank or group of banks seeking credit is of importance for the stability of the financial system and is solvent. In addition, the liquidity assistance must be fully covered by sufficient collateral at all times. At the height of the financial crisis in October 2008, the Federal Council, the Swiss Federal Banking Commission (SFBC; now FINMA) and the SNB adopted measures to stabilise UBS, thereby strengthening the Swiss financial system. The SNB participated in this package of measures by establishing a stabilisation fund (StabFund). In so doing, it assumed its role as lender of last resort.

The stabilisation fund was a special purpose vehicle to which the illiquid assets of UBS were transferred. The SNB granted the stabilisation fund a loan to take over these assets. In November 2013, UBS repurchased the stabilisation fund from the SNB (press release).

The financial market infrastructures that could harbour risks for the stability of the financial system include the Swiss Interbank Clearing (SIC) payment system, the central securities depository SIX SIS and the central counterparty SIX x-clear. These are operated by SIX Interbank Clearing Ltd, SIX SIS Ltd and SIX x-clear Ltd, which are subsidiaries of SIX Group Ltd (www.six-group.com). Other systems that are important for the stability of the Swiss financial system are the Continuous Linked Settlement (CLS) foreign exchange settlement system and the central counterparties Eurex Clearing and LCH.Clearnet Ltd. The operators of these financial market infrastructures are domiciled in the US, the UK and Germany.

The National Bank Act requires the SNB to oversee financial market infrastructures. By overseeing financial market infrastructures operated by the private sector, the SNB promotes their security. In so doing, it gives priority to reducing systemic risk. First, it is important to ensure that neither technical system failure nor financial difficulties on the part of financial market infrastructure operators give rise to major credit or liquidity problems for financial intermediaries, or that these result in severe disruption on financial markets. Second, the legal framework, and, in particular, the rules and procedures for the different systems should be formulated such that payment or delivery difficulties of individual participants in these financial market infrastructures do not spill over to other financial intermediaries, linked financial market infrastructures or the financial markets. To this end, the SNB cooperates with FINMA as well as with foreign supervisory and oversight authorities.