. the great depression – a combination of recession, deflation and bank failures – is a clear historical example of what can happen if central banks fail to provide liquidity to the financial system. the monetary policy measures taken by the ecb have helped to avoid a collapse in money and credit and to eliminate the spectre of the great depression. they have not only avoided a collapse of the financial system, but also, and more importantly, prevented a surge in unemployment and poverty in the euro area. in so doing, we have proven that the three objectives of stability, efficiency and equity are mutually supportive, and that the ecb can effectively contribute to containing inequalities within its treaty mandate. i thank you for your attention. bis central bankers ’ speeches bis central bankers ’ speeches bis central bankers ’ speeches bis central bankers ’ speeches bis central bankers ’ speeches

significant limitations. transacting cryptos on blockchains can be inefficient, slow and expensive ; they face the blockchain trilemma, whereby aiming for optimal levels of security, scalability and decentralisation at the same time is not achievable. crypto - assets relying on a proof - of - work validation mechanism, which is especially relevant for bitcoin as the largest crypto - asset by market capitalisation [ 11 ], are ecologically detrimental. public authorities will therefore need to evaluate whether the outsized carbon footprint of certain crypto - assets undermines their green transition commitments. [ 12 ] moreover, proof - of - work validation mechanisms are inadequate for large - scale use. [ 13 ] bitcoin, for example, can only accommodate up to seven transactions per second and fees can be exorbitant. while alternative solutions to overcome the blockchain trilemma and proof - of - work consensus shortcomings have emerged for faster and more affordable transactions, including those outside the blockchain, they have drawbacks of their own. " off - chain " transactions conducted via third - party platforms compromise the core principles of crypto - assets, including security, validity and immutability. [ 14 ] another important aspect is the operational risk inherent in public blockchains due to the absence of an accountable central governance body that manages operations, incidents or code errors. moreover, the handling of crypto - assets can be challenging. in a decentralised blockchain, users must protect their personal keys using self - custody wallets, which can discourage widespread adoption due to the tasks and risks involved, for example the theft or loss of a key. given the immutability of blockchains, they do not permit transaction reversal. instability another key limitation of unbacked cryptos is their instability. unbacked cryptos lack intrinsic value and have no backing reserves or price stabilisation mechanisms. this makes them inherently highly volatile and unsuitable as a means of payment. bitcoin, for instance, exhibits volatility levels up to four times higher than stocks, or gold ( chart 2 ). chart 2 price volatility of cryptos compared with other assets ( annualised seven - day rolling standard deviation of daily percentage changes of prices ) sources : cryptocompare, bloomberg, refinitiv and ecb calculations. notes : the data are for the period from 1 january 2015 to 15 june