It surpassed the $ billion mark in just two days, making it the fastest growing ETF in history. 14  For instance, Expedia, Tesla and Microsoft. 15  See “Understanding digital bubbles amidst the COVID-19 pandemic: Evidence from DeFi and NFTs”. Y. Maouchi, L. Charfeddine and G.E. Montasser (2021), Finance Research Letters. 16  The idea behind this strategy is to incentivise investors to lend their crypto-assets to a pool that helps provide liquidity to decentralised finance systems, while offering potential investors the highest possible returns at all times. To simplify somewhat, this strategy is structured around smart contracts that select which environment each of the pooled assets will be sent to at any given moment to optimise economic returns for their rightful holders. 5  where they start posing serious threats to global financial stability17. A message that we also conveyed in our latest Financial Stability Report18. Such risks are diverse in their origin. First, they may arise as a result of a limited understanding by investors on the actual features and implications of these assets on the part of investors.19 By way of example, a recent research from the UK’s Financial Conduct Authority (FCA) showed that around 20% of crypto-asset owners assumed an equivalent level of customer protection as with traditional banking products.20 An OECD study reached similar conclusions for the Asian market.21 In general terms, given their volatility and complexity, crypto-assets are not appropriate for retail investors.
In this case, the potential validators disclose their identity to the entire ecosystem, and they are entrusted this role according to their reputation rather than their economic interest. Not only is this mechanism more efficient and more agile, but it is  7  See, for example, the case of JP Coin. 8  https://ethereum.org/en/developers/docs/consensus-mechanisms/pos/. 3  particularly useful in situations with a low number of participants and where potential validators already enjoy trust. The environment in which crypto-assets operate is also characterised by the presence of a wide range of players9 whose services are essential to provide structure and contribute to the proper functioning of the system. Thus, in addition to crypto-asset issuers, there are platforms that help dematerialise pre-existing assets, infrastructures that facilitate the trading and exchange of crypto-assets, institutions that receive, transfer and/or execute third-party orders, as well as market-makers, code developers, providers of custody, wallet and consultancy services and a long list of others. It is, therefore, a highly complex universe, and this complexity is heightened by the fact that these players are based on a broad range of jurisdictions. In this regard, we should also bear in mind the world of decentralised finance (DeFi), which aims to replicate the dynamics of the provision of financial products and services, but in a decentralised and fully automated environment, thus removing the need for intermediaries. The growing importance of crypto-assets With such a wealth of initiatives, the significant developments experienced by cryptoasset markets in recent times may come as no surprise.