Back to school: Borrowing costs top 5%

The yield on the benchmark 30-year Treasury rose to 5.251 per cent on 10 August, just as families were shopping for the new school year. Long-term borrowing costs across the country rose with it, for companies and municipal borrowers alike.

Mortgages near eight per cent

The sell-off at the long end has pushed thirty-year mortgage rates back up towards eight per cent. Home sales have seized up, and plans to refinance commercial mortgages have been hit hard. Municipal borrowers raising money for school buildings, water systems and regional hospitals are paying rates not seen in a generation, and local governments are putting capital projects off.

Mortgage rates follow long Treasury yields because lenders sell most new loans into mortgage-backed securities, which investors price against government bonds of similar duration. When the long end sells off, the rate quoted to a borrower rises within days. The lock-in effect makes it worse, since owners who fixed their loans at far lower rates earlier in the decade have little reason to sell and take on a new mortgage near eight per cent. The last time rates came this close, in October 2023, the Freddie Mac average reached its highest level since 2000 and existing-home sales sank to their weakest in almost three decades.

Schools, hospitals and office towers

Commercial property is exposed for a different reason. Most commercial mortgages run for five to ten years and end with a large repayment that must be refinanced, so loans written when money was cheap are coming due at far higher rates, often against buildings, especially offices, that are worth less than when the loan was made. Owners who cannot cover the gap must inject equity, sell or hand back the keys.

Municipal borrowers face the same arithmetic with fewer escape routes. Tax-exempt bonds are priced against Treasuries, so a school district or water utility issuing long-dated debt now locks in a much higher interest bill for decades and must fund it from property taxes or user fees. Postponing a project defers the cost but keeps ageing pipes and classrooms in service for longer.

The back-to-school shopper is the one borrower the long end barely touches. Credit-card rates track the prime rate, which moves with the Fed's short-term policy rate, so the move in 30-year yields leaves those balances unchanged. The long end bites on the big decisions instead: a house, a new car financed over five or six years and, with a lag, student loans. Rates on new federal student loans are reset each year from the yield at the ten-year Treasury auction in May, so this summer's sell-off will show up in the rates families pay for the following academic year.

Too much debt to place

With 30-year yields above 5.25 per cent, bond buyers want a hefty term premium before they will hold long-dated government debt. Investors at home and abroad will not fund federal deficits running to trillions of dollars at yields below five per cent while inflation risks remain unhedged.

The term premium is the extra yield investors demand for locking money up in a long bond rather than rolling over short-term bills. Estimates of it spent much of the 2010s below zero, when central-bank bond buying and low inflation made duration feel safe. As the Fed shrank its holdings and deficits stayed large, private buyers had to absorb more long debt, and they have charged for the risk. Japanese institutions, long big buyers of foreign bonds, have had less reason to look abroad since yields on Japan's own long bonds climbed to records in 2025.

The Treasury sells long bonds at regular auctions, and the results give an early reading on appetite. An auction tails when the yield it clears at is higher than the rate traders were quoting just before bidding closed, which means the Treasury had to pay up to sell the full amount. Primary dealers are obliged to bid at every auction, so when end investors hold back, the dealers absorb the surplus and must finance it on their own balance sheets until they can sell it on.

When the long end breaks

Britain showed in September 2022 how quickly long-dated debt can become hard to place, when an unfunded budget sent gilt yields soaring and forced the Bank of England to buy long bonds to halt a spiral in pension funds' leveraged hedges. The American market is deeper and the dollar's reserve role gives it more room, but buyers of long debt watch the finance ministry as closely as the central bank. Moody's cited persistent deficits and rising interest costs when it removed America's last triple-A rating in May 2025.

Higher long yields do have beneficiaries. Savers and new buyers of long bonds can lock in the highest long-term yields in years, and defined-benefit pension plans see their liabilities shrink as the rate used to discount them rises. The losers are existing bondholders, homebuyers, builders, owners of commercial property and every borrower whose project only made sense at lower rates.

What could bring relief

The case for relief rests on the economy itself. Long yields this high slow housing and investment, and a weaker economy would pull inflation and eventually yields down, while the Treasury could, as it did in late 2023, lean more on bills and less on long bonds to ease the supply burden. Neither comes quickly. The Treasury's next quarterly refunding announcement in early November, demand at the monthly 30-year auctions and the Fed's September meeting are the tests to watch. With 30-year yields above 5.25 per cent in 2026, companies and local governments will probably shelve more investment projects this autumn, and cheap long-term credit is unlikely to return soon.