I revisit the Diamond-Dybvig model of liquidity insurance in the presence of hidden trades. The key result is that in this environment deposit-taking banks are not necessary for the efficient provision of liquidity. Mutual funds are constrained efficient when supplemented with the same government liquidity regulation that is required to make a banking system constrained efficient. However, whereas banks are potentially subject to costly panics, mutual funds are not run-prone and hence superior from a welfare perspective if runs happen with a non-zero probability.