The 2008 crisis had stigmatized the shadow banking system as resulting of deviant behavior of banks seeking to take advantage of regulatory loopholes. Some had called for its disappearance. Far from having disappeared, shadow banking in 2021 can no longer be approached as a marginal phenomenon. It must now be analyzed as the structural form of the contemporary financial and banking system: it shapes the role and functions of the members of the system, ensures its viability but is also at the heart of its fragility. This article highlights the essential role of shadow banking in transforming the hierarchy of monetary liquidity (Part 1) and in maintaining banking and financial activities despite a deteriorated economic context (Part 2).