The U.S. national debt is approaching the point where bond traders see ‘mounting risk’ of a ‘vicious cycle,’ Moody’s top economist says

The U.S. national debt exceeds $40 trillion, and the debt-to-GDP ratio is 126%; the Treasury reported a $2 trillion deficit for the fiscal year ending in October, with more than half attributable to interest payments. Moody’s economist Mark Zandi warned that investors appear to be demanding higher compensation for risk, as the 10-year Treasury yield has risen about 1 percentage point this year, potentially reinforcing a debt-and-rates spiral. The IMF said the G7’s average 10-year government yield rose by more than 1 percentage point from February to September 2026, reaching its highest level in nearly two decades. GXThe U.S. is not alone in facing higher yields, but Zandi stressed that Treasury-market stress matters especially because Treasuries are the global benchmark.

Analysis

The risk is not simply higher government interest expense: a persistent fiscal term premium would reset the discount rate across U.S. assets, tightening financing conditions even without a Fed hike. Long-duration growth equities, leveraged borrowers and housing are exposed; banks and insurers are not clean hedges because reinvestment yields may improve while bond marks, funding costs and credit quality can worsen. A stronger yield advantage may support the dollar initially, but a confidence-driven repricing could instead lift gold and weaken the dollar—so FX direction is less reliable than duration exposure.

Near term, treat the warning as a risk signal, not proof of a self-reinforcing spiral. Global yield moves and policy uncertainty can explain part of the selloff; the key test is whether U.S. term premium and auction demand deteriorate relative to peers. Over 1–3 months, watch auction tails, foreign demand, inflation expectations, Treasury issuance guidance and budget negotiations. Over 6–18 months, absent credible deficit restraint, elevated term premium could crowd out private investment and pressure equity multiples. The thesis weakens if yields fall with improving auction demand and stable inflation expectations, or if fiscal measures credibly improve the outlook. The source is an economist’s assessment; independently verify market-based term-premium and demand indicators before sizing risk.

Key Decisions for Investors

• Consider a small, risk-defined U.S. curve steepener: short 10- or 30-year Treasury duration against long 2-year duration. It expresses rising fiscal term premium without requiring an outright bearish view on the whole bond market. Reduce or exit if long-end yields fall on strong auctions or recession-driven duration demand; front-end repricing against the position is the principal risk.
• Avoid adding unhedged long-duration U.S. equity exposure solely on the assumption that Treasury yields will mean-revert. Favor relative exposure to cash-generative, lower-duration businesses over long-duration growth until auction demand and term-premium measures stabilize.
• Use a relative-value check before trading outright: compare U.S. yield moves with other G7 sovereigns and track auction tails, bid-to-cover, inflation breakevens and foreign participation. If U.S. underperformance persists across these measures, the fiscal-risk trade gains confirmation; if moves remain broadly global, keep the position small.
• Watch for a second-order credit catalyst: sustained higher benchmark yields can lift refinancing costs for corporate borrowers and mortgage rates, potentially tightening spreads and slowing housing activity. Do not assume bank or insurer shares are automatic beneficiaries; require evidence in funding costs, credit quality and portfolio disclosures.