In July, Treasury Secretary Janet Yellen summoned the chair of the Federal Reserve, the head of the Securities and Exchange Commission, and six other top officials for a meeting to discuss Tether. The absurdity of the situation couldn’t have been lost on them: Inflation was spiking, a Covid surge threatened the economic recovery, and Yellen wanted to talk about a digital currency dreamed up by the former child actor who’d missed a penalty shot in The Mighty Ducks. But Tether had gotten so large that it threatened to put the U.S. financial system at risk. It was as if a playground snowball fight had escalated so wildly that the Joint Chiefs of Staff were being called in to avert a nuclear war.