Long-Dated Corporate Bonds Vanish as 30-Year Yields Hit 20-Year High

Aon Inc. priced $2 billion of notes maturing in 2056 on Monday as part of a $13.5 billion debt package to fund an acquisition. Investor orders exceeded $14 billion, making the 30-year tranche the most sought-after portion of the seven-part offering.

The surge in demand masks a deepening scarcity in the long-dated corporate bond market. Sales of investment-grade notes this month have fallen to less than half year-earlier levels, with long-dated bonds accounting for just 5 percent of total issuance in early September—the smallest share for this period since at least 2020.

Companies are canceling long-term debt offerings as 30-year yields have climbed to their highest level in nearly two decades. The higher borrowing costs make it increasingly difficult for corporate treasurers to justify locking in expensive funding for decades.

The supply gap has created a duration crisis for institutional investors. Pension funds and insurers, which depend on long-dated bonds to match long-term liabilities, now face severe constraints. GSK Plc's bond sale last week saw investor demand for its 30-year tranche reach 15 times the size of the $500 million offering—a sign of institutional desperation for scarce long-duration assets.

The shift also exposes a structural problem for hyperscalers. Alphabet Inc. and Amazon.com Inc. which have relied heavily on long-dated bonds to finance artificial intelligence infrastructure buildout, now face higher costs for the extended-maturity funding they require.

Neil Sun, a portfolio manager at RBC Global Asset Management Inc. said: "With yields remaining elevated, it is increasingly challenging for corporate treasurers and CFOs to make the case for long-dated funding." Sun noted that no near-term reversal is likely, with robust U.S. growth and AI capital expenditures expected to keep rates higher for longer.

In secondary trading, Aon's 30-year note has outperformed the deal's shorter-dated tranches, reflecting the acute bid for duration in a market where new long-term supply is being rationed by cost.