What if you could borrow money on the cheap and use it to pay for just about anything? The U.S. government can, and does, with U.S. Treasuries. But the market for Treasuries might be more fragile than we know. In this episode, Yesha Yadav of Vanderbilt Law School explains why. This episode was first published as a bonus episode for our Planet Money+ listeners. Today we're making it available for everyone. To hear more episodes like this, and to hear Planet Money and The Indicator without sponsor messages, support the show by signing up for Planet Money+ in Apple Podcasts or at plus.npr.org/planetmoney.