Investor demand for higher risk premiums on long-term government bonds pushed the average yield across the Group of Seven nations to its highest level since 2008 in mid-August, underscoring growing unease about the trajectory of global sovereign debt markets.

The exodus from long-dated sovereign debt reflects widening fiscal deficits and sticky inflation. At the same time, technology companies are increasingly tapping the bond market to fund artificial intelligence infrastructure buildouts, forcing governments to compete with corporate issuers for investor attention.

After U.S. Treasury yields touched their highest point in nearly two decades, the Treasury Department announced an expansion of its long-dated bond buyback program. The unexpected move helped steady the market and reversed some of the recent yield gains, though it did not fully erase the upward pressure.

What makes long bonds unique?

Bonds issued by wealthy nations are widely regarded as the world's safest securities, with repayment to investors almost assured. Governments typically lock in financing costs for extended periods, often up to 30 years, and some have even issued century bonds.

Yet these securities are not without risk. If inflation and short-term interest rates climb, the real value of coupon payments erodes, as does the principal ultimately repaid at maturity. The longer the bond's duration, the more time inflation has to take its toll, which explains why long-dated bonds are more sensitive to rising rates and inflation and have been at the epicenter of the recent selloff.

In mid-August, the 30-year U.S. Treasury yield reached its highest level since 2007, German 30-year yields returned to peaks not seen since 2011, and Japan's 30-year yield approached historic highs.

Why are long and short bonds diverging?

Investors worry that central banks are not doing enough to contain inflation, which has proven persistent amid the trade war waged by U.S. President Donald Trump and energy costs driven higher by Middle East conflicts.

The selloff in U.S. long-term Treasuries intensified in July after the Federal Reserve held interest rates steady. Fed Chair Kevin Warsh's stance led investors to question his commitment to returning inflation to the Fed's 2% target after it has exceeded that goal for more than five consecutive years.

Holding rates unchanged helps keep short-term yields lower, since they are closely tied to the near-term outlook for central bank policy, but it undermines long-term bonds as investors fear inaction will fuel future inflation pressures. This has widened the gap between short-term and long-term yields, a trend known as a steepening yield curve.

The issue is not confined to the United States. In Japan, the central bank's gradual rate hikes have left interest rates among the lowest in the developed world. Prime Minister Takako Takai has been cautious about raising rates too far or too fast, wary of choking off the economic recovery. As a result, Japan now has the steepest yield curve among major bond markets.

Aren't investors attracted to higher yields?

In theory, yes, but bond market supply and demand are undergoing structural change. For much of the past two decades, abundant global savings, particularly from Asia, chased relatively scarce safe assets, suppressing long-term real yields. Former Fed Chair Alan Greenspan once called the persistent low level of long-term yields a "conundrum," noting that long rates stayed low even as the Fed raised short-term borrowing costs.

Today, governments are boosting spending across areas ranging from renewable energy to defense. The United States needs to increase borrowing both to service a national debt approaching $40 trillion and to cover an annual fiscal shortfall that the Congressional Budget Office estimates at $2.1 trillion.

Just as global government bond supply surges, demand has weakened, partly because foreign appetite has shrunk and partly because central banks are reducing their holdings after years of buying. Isabel Schnabel, a member of the European Central Bank's Executive Board, has described this shift as a transition from a "savings glut" to a "bond glut."

This means the investor base is tilting toward more price-sensitive private buyers, who typically demand greater compensation for holding long-dated bonds. Structural changes in pension systems and retirement arrangements have also shrunk the pool of traditional buyers.

How does the long-bond storm affect Asian markets?

Global fund managers believe that if the 10-year U.S. Treasury yield rises further toward 5%, Asian emerging market bonds could face capital outflow pressure.

Additionally, the recent Treasury selloff has driven notable weakness in the U.S. dollar, broadly benefiting Asian currencies. The Korean won has led gains among Asian currencies over the past month.

What premium are investors demanding for long bonds?

The United States has traditionally enjoyed a "convenience yield" on its debt, where investors accept lower returns because Treasuries are highly liquid, safe, and usable as collateral. Some argue this privilege has eroded significantly due to the growing U.S. debt burden and Trump's unpredictable policymaking. Others contend such concerns are overstated and that U.S. Treasuries remain the safest bonds available.

Why do long-term yields matter for the economy?

A disorderly selloff in bond markets can spell trouble for governments relying on debt markets to finance fiscal deficits. The United Kingdom knows this well, as demonstrated by the collapse of Liz Truss's government in 2022. U.S. Treasury Secretary Scott Bessent remarked earlier this year that bond markets have "toppled more governments than howitzers."

Long-dated yields serve as an important pricing benchmark for numerous consumer loan rates, including mortgages, and corporate debt financing costs. Rising bond yields could add further pressure on household borrowers, who are already struggling with higher living costs after years of inflation. Savers, however, stand to benefit.

The transmission from bond yields to consumer credit markets is not always direct. In the United States, for instance, 30-year mortgage rates are more closely tied to 10-year Treasury yields than to 30-year yields, because homeowners typically pay off or refinance their mortgages within roughly ten years.

How does the AI spending boom affect long bonds?

As technology companies seek to expand AI infrastructure, they are increasingly issuing long-term bonds so that principal repayment to investors comes due decades later. This means governments face greater competition from corporate issuance when raising funds.

Investment-grade companies, including major tech firms, have issued nearly $1.5 trillion in bonds so far this year, a 36% surge from the same period last year. Nomura estimates that roughly $200 billion borrowed by just the largest technology companies equals about 25% of the U.S. Treasury's net issuance of medium and long-term debt to private investors, five times the share seen in 2025.

Bank of America economists note that the surge in corporate bond issuance, combined with increased mortgage-backed securities supply, has pushed the 10-year Treasury yield up by approximately 30 basis points this year.

What measures are governments taking?

Many governments are shifting their issuance plans toward shorter-dated bonds. While short-term yields are currently lower, shorter maturities also mean governments must refinance more frequently, potentially at higher rates.

The U.S. Treasury said it would at least double its buyback operations for 10-to-30-year bonds between September and November to "provide greater liquidity support for the long end of the yield curve." Following the announcement, yields on long-term U.S. Treasuries and other government bonds generally declined, but the durability of this impact remains to be seen.

More broadly, governments need to convince investors they can control inflation and fiscal deficits. This may require a combination of tax increases and spending cuts, measures that are likely to be unpopular with voters.

Should investors be worried about rising yields?

To some extent, rising yields are good news for bondholders. With equity markets at historic highs, higher yields reflect a global economy resilient enough to absorb higher borrowing costs.

Following the global financial crisis, growth prospects were bleak and yields were near zero. The recent rise in yields can therefore be viewed as normalization toward pre-crisis levels. Currently, the 10-year U.S. Treasury yield stands at 4.7%, roughly in line with its 40-year average.

Wells Fargo economists Tom Porcelli and Michael Pugliese wrote in an August research note that people like to use the phrase "higher for longer." They argue a more accurate description would be "normal for longer."