The yield on the 30-year US Treasury bond climbed to roughly 5.29% on Monday, its highest level since 2007 and closing in on that year's financial-crisis-era peak of 5.44%. The move caps a monthlong selloff in long-dated government debt that is forcing borrowers, from Washington to Wall Street, to pay far more to lock in money for decades.

The pressure has been building for weeks. Last week's $25 billion auction of new 30-year bonds cleared at a yield of 5.216% — the highest auction rate since 2001 — while a separate 10-year note auction drew the highest financing cost for the government since 2007. Over the past month, 30-year yields have risen more than 13 basis points even as short-term two-year rates fell about 12 basis points, a steepening pattern that signals investors are demanding a much bigger premium to hold debt over the long haul.

What's Driving It

Analysts point to a mix of forces: inflation that has stayed above the Federal Reserve's 2% target for roughly five straight years, a surging pile of federal debt issuance, a wave of corporate bond sales to finance AI data-center construction, and cooling demand from the traditional pension funds and insurers that once anchored the long end of the market.

"WE HAVE BEEN ARGUING AGAINST FADING THE LONG END SELL-OFF, AND WE CONTINUE TO DO SO"

"We have been arguing against fading the long end sell-off, and we continue to do so," said Anshul Pradhan, Barclays' head of US rates strategy, one of several Wall Street voices warning clients not to bet on a quick reversal.

Higher long-term yields ripple well beyond the bond market: they push up rates on 30-year mortgages, corporate debt and municipal borrowing, and they raise the government's own interest bill on its more-than-$37-trillion national debt. With the Federal Reserve's next policy meeting still weeks away and no clear catalyst in sight to slow federal borrowing, traders are bracing for yields to stay elevated — or climb further — into the fall.