Definition
The total amount the federal government owes, built up from past deficits.
The story
Each year's deficit adds to the pile. Total US public debt passed $38 trillion in October 2025, according to Treasury data. The government pays interest on that debt, and as rates rose, those interest costs climbed with them.
Why markets watch it
The size of the debt and the cost of servicing it feed into debates over taxes, spending and long-term interest rates.
Connects to
Budget deficitDebt limitTreasury bills, notes and bondsCredit rating
We explain why it moves markets. What you do with it is your call. Commentary and education only. Not financial advice. All terms