US Debt at 100% of GDP: Why the 10-Year Treasury Yield May Still Hit 5.5% in 2026

The United States now owes more than it produces. At the close of fiscal year 2026, federal debt held by the public reached $32.2 trillion — 100.03 percent of gross domestic product, according to the Treasury Department's September statement, as reported by the Wall Street Journal. It is the first time the ratio has crossed 100 percent at a fiscal year-end since 1946, when postwar borrowing pushed it to 106 percent. The road there was long and almost unremarked: the ratio was 33.7 percent in 2000, 99.4 percent a year ago, and now it has passed the whole economy.

The arithmetic behind the milestone is blunt. The federal government spent about $7.4 trillion in fiscal 2026 and collected about $5.4 trillion, leaving a deficit of roughly $1.99 trillion — 6.2 percent of GDP, the largest shortfall since 2021. Net interest on the debt cost $1.052 trillion, up 8.2 percent from the year before and the first time the annual interest bill has passed a trillion dollars: nearly $2.9 billion every day, just to stand still. The Congressional Budget Office projects the ratio reaching 120 percent by 2036 on current policy, past the 1946 record. The Government Accountability Office has calculated what holding the line would take — 26 percent more revenue every year, or 21 percent less spending, starting now.

What makes this more than a round number is who is no longer buying. The Federal Reserve's quantitative tightening cut its Treasury holdings by $1.7 trillion between 2022 and 2025, and foreign official holdings have fallen too. Bloomberg found that Washington's closest allies bought a net $174.3 billion of Treasuries in the first eight months of 2026, down more than 60 percent from a year earlier and the least for that stretch since 2021. The share of Treasuries held by price-insensitive public-sector buyers — the Fed and foreign central banks — has shrunk to 27 percent, from 46 percent in 2016. More of the debt must now be sold to buyers who care about the price, and the price has been moving.

The 10-year Treasury yield, the benchmark for mortgages and global borrowing, rose to 5.01 percent in September, its first breach of 5 percent since October 2023. It has since eased — Finnhub's data put it at 4.84 percent on November 5 — but the market's own record shows how close the next line is: Polymarket's contracts for the yield touching 5.2 and 5.3 percent before year-end have already resolved in favour of "yes". The December Federal Reserve meeting is another push in the same direction: Kalshi and Polymarket both price a quarter-point hike on December 8–9 at about 80 percent, and the October jobs report — 165,000 jobs added against 59,000 expected, unemployment down to 4.1 percent — gives the hawks cover.

The counterweight is real, and it is the same force that has defined this week. Thursday's equity sell-off, the worst single-day loss for the S&P 500 since April 2025, sent money fleeing into bonds; that flight is what pulled the 10-year back below 5 percent. A growth scare does the same thing faster. And the September breach lasted a single day in 2023's case too — the last time the yield topped 5 percent, in October 2023, it stayed there for one day.

So the honest call is a long shot, not a forecast of doom. Polymarket prices the 10-year reaching 5.5 percent before 2027 at about 4.5 cents — a 4.5 percent chance. I put it higher, at 15 percent. The yield has already printed above 5.2 percent in this cycle, the December hike is the market's base case, and the Treasury must place a growing pile of debt with buyers who now demand compensation for it. Against that, the flight to safety is powerful and the Fed could still blink. But 5.5 percent is not a distant scenario: it is one bad auction, or one hot inflation print, away from a market that has already shown it can get there. The debt crossing its economy is a fact; whether the market charges America 5.5 percent to carry it is the question the next seven weeks will answer.

Sources: US Treasury Department, September Monthly Treasury Statement; Congressional Budget Office; Government Accountability Office; Finnhub (10-year yield, November 5, 2026); Polymarket.