Why do banks sometimes fail?

Answer: Too many loan defaults occur

Employees steal all deposits — Wrong. While fraud can damage banks, failures are typically caused by bad loans—when economic downturns or poor lending decisions result in massive loan defaults that exceed the bank's capital reserves.

Too many loan defaults occur ✓ — Correct! Banks fail when loan losses exceed their capital cushion. Banks lend most deposits to borrowers. If too many borrowers default (can't repay loans)—due to recession, housing crash, or risky lending—the bank's losses mount. If losses exceed reserves, the bank becomes insolvent (liabilities exceed assets) and fails.

Currency printing runs out — Wrong. Regular banks don't print currency—only central banks do that. Commercial banks hold deposits and make loans electronically. Bank failures happen when loan losses exceed their capital, not because of any physical cash shortage.