In late 2022 and early 2023, a number of banks experienced deposit runs that were extraordinarily fast and large by historical standards. To explain these historically unprecedented developments, banking regulators have focused on three factors: (i) changes in technology that have enabled faster withdrawals, (ii) social media that facilitated information dissemination and coordination among depositors, and (iii) uninsured deposits that were concentrated among bank customers with connections to each other (Federal Reserve, 2023a and 2023b; FDIC, 2023a and 2023b; New York DFS, 2023; California DFPI, 2023). This essay ... (full story)