US bond yields surge past 5% on toxic mix of inflation, AI spending, and ballooning deficits

The 10-year US Treasury yield briefly touched 5.041% on September 15, a level not seen since July 2007. The 30-year yield crept toward 5.3%, a two-decade high.

What’s driving the move isn’t any single catalyst. Persistent inflation, geopolitical conflict pushing oil prices higher, a federal government borrowing at wartime levels during peacetime, and an AI investment boom that’s sucking up capital at an extraordinary pace — economists have started calling this a “toxic stew” of converging pressures.

The ingredients of the stew

The Consumer Price Index grew 3.4% year-over-year as of August 2026 data, stubbornly above the Federal Reserve’s 2% target. Oil prices surged above $100 per barrel, driven by supply disruptions tied to the Iran conflict. The 10-year yield has climbed more than a full percentage point since the Iran conflict escalated, and more than half a percentage point since May alone.

US federal debt now sits at roughly $40 trillion, with annual deficits exceeding $2 trillion — about 6% of GDP, a deficit ratio typically associated with recessions or major crises, not an economy still posting resilient growth numbers.

Treasury Secretary Scott Bessent has expanded bond buyback operations to at least $4 billion, buying back older, less liquid bonds to ease pressure on long-term yields. The results so far have been underwhelming, with critics arguing the buybacks are too small relative to the scale of issuance to meaningfully move the needle.

AI’s surprising role in the bond market

Hyperscalers — the handful of tech giants building massive data center and compute infrastructure — are projected to issue approximately $250 billion in bonds in 2026, a number expected to balloon to $400 billion in 2027. These companies are competing for the same pool of investor capital that the US government is tapping to finance its deficits.

The Fed factor and what comes next

A Bank of America survey indicates investors anticipate a 25 basis point interest rate hike from the Federal Reserve around September 16. Mortgage rates track closely with the 10-year yield, meaning housing affordability takes another hit. Corporate borrowing costs rise, and consumer credit — from auto loans to credit cards — gets more expensive.

Higher yields make bonds a more attractive alternative to stocks on a risk-adjusted basis. They also raise the discount rate used to value future earnings, hitting growth stocks, particularly in tech, disproportionately hard.

Geopolitical tensions around Iran show no signs of de-escalating. Federal deficits are structurally embedded. AI capital expenditure is accelerating. And the Fed appears committed to keeping rates elevated until inflation convincingly returns to target.