By Kevin Kidney, head of investments at True Potential
Consumer price inflation hovering above 3%, the S&P 500 trading near all-time highs, and Treasury yields surging toward 5%. This is not merely an echo of late 2023, but the defining economic backdrop of 2026. What was once dismissed as a transient funding friction has hardened into structural tension within sovereign bond markets.
Last week’s Treasury intervention brought this strain into sharp relief. The announcement from Secretary Scott Bessent to double quarterly buybacks of long-dated T-Bonds, from $2bn to $4bn, initially sparked a 10-basis-point drop in 30-year yields.
Yet, the rally had evaporated entirely by the week’s end. This rapid reversal revealed the limits of debt management manoeuvres, ironically in the same week that total US federal debt breached the $40trn threshold – a staggering $7trn increase since 2023.
The immediate structural issue for the US Treasury lies at the shortest end of the yield curve: Treasury bills. While T-bill funding costs track Federal Funds expectations and still sit below early-2025 peaks, the challenge is one of sheer capacity. Prior to 2020, T-bills accounted for roughly 15% of total outstanding debt.
Today, that figure approaches 20%, representing nearly $7trn and surpassing the size of the long-term T-Bond market. Because the Treasury must issue short-term bills to fund long-bond buybacks, the policy is essentially cannibalising its own ‘front-end’ capacity. The implicit signal is unmistakable. Short-term issuance is reaching its absorption limit, forcing the US Treasury back toward long-dated issuance where higher yields directly compound the national debt burden.
With annual US interest expense surpassing $1trn – now eclipsing the national defence budget – the cost of refinancing has reached critical mass. Lower yields are needed, but all of President Trump’s major policy initiatives have been to the contrary – further tax cuts, then tariffs and now war. With mid-term elections on the horizon, Secretary Bessent’s actions had a whiff of unease about them.
Three decades of deficits
This funding dilemma brings structural fiscal deficits across the developed world into sharper focus. The US deficit remains entrenched near 6% of GDP, while the UK’s structural deficit persists near historical highs despite modest recent cooling. The era of deficit reduction is over. Surpluses are politically unattainable, and fiscal orthodoxy has been entirely supplanted by fiscal populism across the political spectrum. The last fiscal surplus in either country was 25 years ago.
Sovereign bond markets have reacted by reasserting some price discipline. When the Federal Reserve cut rates by 100 basis points in late 2024, long-term Treasury yields paradoxically spiked by a full percentage point to end the year higher – a dynamic mirrored in the UK Gilt market.
Clearly, central banks moved too fast to ease policy in the face of persistent, above-target inflation. With government bond yields in both economies now hovering at 25-year highs, investors are issuing a clear verdict: central banks have now been too accommodative of another inflation impulse and believe higher interest rates are a warranted response.
The yield curve is no longer just a monetary policy barometer, it is a live assessment of sovereign creditworthiness and fiscal sustainability. Government, whether in the US or the UK, would be wise not to overly stress-test this dynamic.
The equity paradox and the impending reckoning
Paradoxically, the fiscal largesse tormenting bond markets has provided fuel for risk assets, such as global equities. Heavy deficit spending combined with accommodative financial conditions has inflated nominal GDP and bolstered corporate earnings. Global equity benchmarks from New York to Tokyo trade near record highs as corporations successfully pass persistent input costs directly onto consumers, preserving operating margins.
Buoyant earnings growth has also supported the interest obligations of corporations themselves, explaining why the spread of this corporate debt over that of government debt is near record lows. Private corporations have been prudent managers of their debt burdens in this economic cycle.
In the near term, this dynamic continues to support diversified multi-asset portfolios with a flexible global mandate. However, this equilibrium could become fragile. Artificial demand cannot suppress long-term yields indefinitely when debt burdens are compounding at exponential rates.
Eventually, the bond market will call time on sovereign largesse… governments must be aware of an unvarnished fiscal reckoning.
