US Debt Hit $40 Trillion in August: What It Means for Rates

Total U.S. public debt crossed $40.05 trillion on August 18, five months after it broke $39 trillion in March, according to Treasury's Debt to the Penny data. By August 19 the figure sat at $40.01 trillion, up $2.80 trillion, or 7.5%, from a year earlier. The round number makes headlines, but the trajectory is what moves markets, and it arrived in the middle of a bond rout that had already pushed the 30-year Treasury yield to 5.34% on August 17, the highest level since 2007.

Key Takeaways Total U.S. public debt hit $40.05 trillion on August 18, 2026, and stood at $40.01 trillion on August 19, up $2.80 trillion (7.5%) year over year, per Treasury Fiscal Data. The 30-year Treasury yield touched…