Bond markets are flashing a warning, two universities are thriving while others struggle, and a baseball fan built a better app than MLB — then got hired for it.

The bond market's "mass unfollow"

Government bond markets are tanking across the globe, and it's rattling Wall Street. The 30-year Treasury yield just hit its highest level in the United States in 20 years. Japan's bond yields are the highest in 30 years. France, Germany, and the United Kingdom are seeing the same pattern. The S&P 500 is down 1% in the last week as a result.

Here's the mechanism: a bond is a tradable loan — an IOU you can buy or sell. When investors sell government bonds instead of buying them, governments have to offer higher interest rates to make their bonds attractive again. That raises borrowing costs for everyone, because mortgages, student loans, and car loans all move with government bond interest rates.

The context is stark. The U.S. government debt hit $40 trillion — $117,000 per American citizen. That's double the $20 trillion it was in 2017. And now interest rates on that debt are 5% instead of 3%. Interest payments are the U.S. government's second biggest expense, behind only Social Security and ahead of military spending.