We develop a tractable model of systemic bank runs. The market‐based banking system features a two‐layer structure: banks with heterogeneous fundamentals face potential runs by their creditors while they trade short‐term funding in the asset (interbank) market in response to creditor withdrawals. The possibility of a run on a particular bank depends on its assets' interim liquidation value, and this value depends endogenously in turn on the status of other banks in the asset market. The within‐bank coordination problem among creditors and the cross‐bank price externality feed into each other. A small shock can be amplified into a systemic crisis.

We investigate the link between exchange-traded funds and real investment. Cross-sectionally, higher ETF ownership is associated with an increased sensitivity of real investment to Tobin’s q and a heightened ability of stock returns to forecast future earnings. Inclusion of stocks in industry ETFs enhances investment-q sensitivity and implies greater incorporation of earnings information into prices prior to public releases. Greater nonmarket ETF ownership leads to increased (reduced) reliance of real investment on own (peers’) stock prices. Overall, the evidence is consistent with ETFs positively affecting real investment efficiency via greater flows of information.