The Treasury, the Federal Reserve, and the Federal Deposit Insurance Corporation announced on Sunday that they will guarantee all deposits that were still held at the ill-fated Silicon Valley Bank when it collapsed last Friday. This is probably a good thing. SVB was the sixteenth-largest bank in the United States, with tens of billions in holdings still trapped behind its crumbling walls. Vaporizing that much money might have had dire implications for other parts of the American financial system—and for thousands of innocent customers who believed their money to be safe within SVB’s coffers. The actions these government entities have...