Against this background, this box presents developments in euro area bank bond issuance and spreads over the past years and discusses possible financial stability implications. An orderly withdrawal of the United Kingdom from the European Union poses a limited overall risk to euro area financial stability. But the uncertainty accompanying a cliff-edge Brexit could have the potential to pose a more significant downside risk to financial stability. ESTER (euro short-term rate) is the alternative euro risk-free rate administered by the ECB, which will replace EONIA (euro overnight index average) in 2020. The European Money Markets Institute (EMMI), the administrator of EONIA, concluded that under current market conditions, EONIA’s compliance with the EU Benchmarks Regulation (BMR) by January 2020 "cannot be warranted". This implies that the usage of EONIA, at least in new contracts, may be prohibited by law as of 1 January 2020. SESFOD is a quarterly survey launched in 2013 as a Eurosystem initiative to collect information on changes in credit terms and conditions on euro-denominated securities financing and over-the-counter (OTC) derivatives markets. The survey is based on 28 large banks, comprising 14 euro area banks and 14 banks with head offices outside the euro area. Banks answer questions at a quarterly frequency regarding how they changed the terms and conditions (both price and non-price) offered to their clients, as well as providing a ranking of the motivations underlying their decisions. The information collected in the survey is useful to assess financial stability, market functioning and the monetary policy transmission mechanism. The survey provides useful insights into the ability of financial intermediaries to secure funding and hedge risks. Buoyant conditions and loose terms may lead to high leverage, while excessively tight terms may provide insights into possible market dysfunctionalities. Liquidity in the Italian sovereign bond market deteriorated sharply at the end of May. Heightened political uncertainty led to a rise in Italian sovereign bond yields and triggered a short-lived flattening of the yield curve (see Chart 2.12, right panel). At the same time, liquidity conditions deteriorated significantly. On 29 May intraday bid-ask spreads increased to levels not seen since the height of the euro area sovereign debt crisis in 2011 (see Chart A, left and right panels). On the interdealer MTS platform specialised in the Italian market, the ratio of the bid-ask spread to the mid bid-ask price for the most recently issued ten-year (on-the-run) bond – a measure that moves inversely with market liquidity – rose from below 0.1% to above 5%. The resilience of the market has been adversely affected too. Orders larger than €50 million could no longer be executed at the best five prices quoted by participating dealers, according to intraday order-book data. This box describes a simple structural Bayesian vector autoregression (BVAR) model that uses sign restrictions to determine the relative importance of distinct economic and financial shocks in shaping the co-movement of key global financial variables. The model provides intuitive and economically plausible interpretations of gyrations in key US and global asset markets over the past six months.