After months of living with the coronavirus pandemic, American citizens are well aware of the toll it has taken on the economy: broken supply chains, record unemployment, failing small businesses. All of these factors are serious and could mire the United States in a deep, prolonged recession. But there’s another threat to the economy, too. It lurks on the balance sheets of the big banks, and it could be cataclysmic. Imagine if, in addition to all the uncertainty surrounding the pandemic, you woke up one morning to find that the financial sector had collapsed.