The U.S. government is set to sell 30-year bonds at the highest interest rate in a quarter century, following a historic selloff that has fueled speculation the nation will shift borrowing further toward shorter-dated maturities.

The Treasury will offer $25 billion in 30-year debt at its monthly auction later on Thursday. In the when-issued market, where securities trade before they are formally sold, the new bond carries a projected yield of approximately 5.23% — which would mark the highest borrowing cost since 2001.

Elevated government financing costs present a challenge for President Donald Trump and Treasury Secretary Scott Bessent heading into November's midterm elections. These costs are already rippling through the broader economy after years of high inflation and increased government spending, as long-term Treasury yields serve as benchmarks for 30-year mortgage rates and corporate borrowing costs.

The Treasury's concern surfaced last week when officials adjusted their debt-sales guidance in a manner that opened the door to potential reductions in long-bond supply. At the same time, investors remain reluctant to lock in yields at multi-decade highs, signaling collective wariness that the selloff may not yet be finished.

"We're not really at a level where people seem to be going crazy, saying 'I want to buy the 30-year,' and that should be a warning," said John Fath, a managing partner at BTG Pactual Asset Management US LLC. "Bessent may try to address it by decreasing supply, but there's already a lot of 30-year paper issued, so it's not necessarily just new supply driving price action. It's new sellers."

Long-term yields surged past 5% this year as investors worried that rising energy prices would intensify cost pressures, potentially compelling the Federal Reserve to maintain elevated interest rates for years. That comes on top of increased Treasury supply driven by years of fiscal deficits, a sudden surge in corporate borrowing to finance the artificial-intelligence boom, and declining demand from traditional buyers of long-dated bonds — a group that includes foreign central banks and, since the Federal Reserve began reducing its balance sheet through quantitative tightening, the Fed itself.

On Thursday, yields fell by two to three basis points across maturities after a U.S. producer prices report provided additional evidence that inflationary pressures are moderating. Traders reduced their expectations for a Federal Reserve rate hike in September to approximately 35% probability, down from roughly 50% earlier in the week.

Interest on the public debt remains a major driver of the nation's budget deficit. For the fiscal year to date, the total stands at $1.17 trillion — a 15% increase, attributable in part to higher Treasury yields. On Wednesday, a 10-year note sale drew the highest yield for that maturity since 2007.

"We expect today's 30-year auction to clear without difficulty, but a successful auction shouldn't be confused with strong structural demand for long-duration assets," wrote Michal Stanczyk, a portfolio manager on the Global Fixed Income team at Allspring Global Investments, in a note.

If prices hold near current levels for the 30-year auction scheduled for 1 p.m. in New York, it would produce the highest borrowing rate since the Treasury discontinued the long bond in 2001 — a decision infamously leaked to Goldman Sachs traders before the public announcement and later reversed in 2005.

Today's landscape is markedly different from that era. Bond investors at the time were reaping the rewards of a multi-decade bull market, and a string of federal budget surpluses had even sparked concern that U.S. government debt supply was too low. By contrast, the total volume of Treasuries outstanding is now ten times larger and expanding rapidly, having doubled since 2018 to approximately $31 trillion.

As traditional demand sources have pulled back from Treasuries, private market participants have filled the gap — demanding higher yields in return.

"As the market becomes increasingly reliant on price-sensitive investors, the same amount of Treasury supply may require a larger yield concession to clear," wrote a Barclays Plc team led by Demi Hu.

Guidance Tweak

The future scale of long-bond sales has been a subject of debate over the past week, after Treasury officials made an unexpected revision to their latest quarterly borrowing policy statement. Rather than stating they are continuing to evaluate potential future "increases" in coupon and floating-rate note sales — as previously worded — officials said they are considering potential "changes."

Bond investors interpreted this as raising the likelihood that officials will reduce sales of the long bonds facing the greatest pressure. Even if such a reduction does not materialize, market consensus holds that when the Treasury eventually moves to larger fixed-income auctions, it will likely concentrate on shorter-maturity notes maturing in two to seven years.

That would extend the Treasury's current maturity-shortening strategy, under which officials have shifted issuance toward bills maturing in one year or less. This approach sidesteps the higher yields on longer tenors but increases refinancing risks, as a larger share of government debt must be rolled over at prevailing market rates on a more frequent schedule.

"The only clear solution I see is the U.S. government tightening its budget," Fath said regarding how to reduce long-term borrowing costs. "The whole game plan of trying to move issuance up to the front end: You can only do that so much, right? Then it becomes what I would call irresponsible."