The Moody’s announcement sent the yield on a 30-year Treasury bond to a high of 5.01% at one point on Monday. Bond yields rise as bond prices fall. When a selloff hits and demand for bonds dries up, it sends bond prices lower. In turn, bond yields move higher.

Moody’s decision to join other major ratings agencies in downgrading the U.S.’s once-pristine credit rating could have a tangible impact on Americans’ wallets. The agency has dropped the U.S. sovereign credit rating—an assessment of the country’s ability to pay its debts—down one level from the highest possible Aaa to Aa1.