We propose a unified framework to study liquidity provision by debt-issuing versus equity-issuing financial intermediaries. We show that both types of intermediaries provide liquidity by insuring against idiosyncratic liquidity risks as in Diamond and Dybvig (1983) but with distinct frictions....

Exchange-traded funds (ETFs) are typically viewed as passive index trackers. In contrast, we show that corporate bond ETFs actively manage their portfolios, trading off index tracking against liquidity transformation. In our model, ETFs optimally choose creation and redemption baskets that...