(Bloomberg) — Jamie Dimon said interest rates may climb much further, a warning to bond investors at a time when yields have touched multi-year highs.

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“They could be much higher than they are today,” the chairman and chief executive of JPMorgan Chase & Co. said in an interview with Bloomberg Television. “We may have gone from a saving glut to not enough savings.”

Long-dated bonds have come under pressure on concern that higher oil prices may compel central banks to raise interest rates. Add in worries over government spending in Japan, the UK and the US, as well as an artificial intelligence boom supporting growth in the world’s biggest economy, and investors have been seeking greater compensation to own longer-maturity debt.

“Bond rates can go up,” Dimon said. “The notion that somehow people say they will never go up is the wrong notion. Companies like us prepare for higher rates, lower rates.”

Yields on 30-year Treasuries rose to levels last seen in 2007 this week while the rate on two-year securities climbed to the highest since February 2025. The moves reflect investors’ worries about the inflationary impact of the Iran war and deficit risks in the world’s biggest economy.

Bonds weakened again Thursday, with yields hitting the day’s highest levels after Reuters reported that Iran’s Supreme Leader has issued a directive that the country’s near-weapons-grade uranium should not be sent abroad. That’s a potential setback for any peace deal, given the US has been pushing Tehran to surrender its enriched uranium stockpile. Oil spiked on the report.

The US two-year yield rose as much as five basis points to 4.11%, while the 10-year yield rose four basis points to 4.62%.

With little sign that the Middle East conflict will be resolved anytime soon, traders are penciling in a 70% chance of a quarter-point Federal Reserve rate hike by December, with a 25-basis point increase by March seen as a virtual certainty. That compares with expectations for more than two quarter-point rate cuts by the end of the year before the Iran war broke out, swaps show.

“US government debt is $30 trillion, the average rate is 3.5%. Even today they can’t possibly refinance it lower than that rate,” Dimon said. “They have another $2 trillion to do this year but the thing is we don’t know when — we don’t know when the world gets too scared about that, when inflation makes it where people don’t want to own long-term duration securities.”