Global bond market sell-off as yields reach multi-decade highs

September 1, Tokyo, 9:00 AM.

The trader’s hand, holding a cup of coffee, froze mid-air. On the screen: Japan’s 10-year government bond yield at 3.0%. The last time this number appeared was in 1996.

On the same day in London, the UK 10-year yield reached 5.23%, the highest since 2008. The 30-year yield hit 5.9%, the first time since the late 1990s. During New York trading, the U.S. 10-year yield stood at 4.78%, and the 30-year yield touched its highest level since 2007.

Within a week, several of the most important interest rate curves on Earth were simultaneously pinned at levels unseen for a long time. Headlines all used the same word: sell-off. It felt as if something had suddenly collapsed.

But it wasn’t sudden at all. Look back six months, and you’ll see it was a slow burn—so slow that no one smelled the smoke.

What are government bonds? They are IOUs issued by the government. What is yield? It’s the interest rate on that IOU—the longer the term, the higher the interest, and the lower the bond’s price in the market. When the bond market sells off, suddenly no one wants to hold any IOUs worldwide.

The fuse doesn’t start in New York—it begins in the Strait of Hormuz. Since February 28, this world’s most critical energy corridor has been half-closed for over six months—184 days—with traffic reduced to just 20% of pre-conflict levels. What’s locked up isn’t just oil: diesel is already experiencing regional shortages; the Gulf accounts for 46% of global urea trade, directly impacting the next planting season; Qatar alone supplies one-third of the world’s helium. This isn’t about being unable to afford it—it’s about being unable to buy it at all.

If you can't buy it, raise the price. Crude oil has been hovering above $90, 25% higher than before the war. As oil prices rise, everything else follows—Eurozone inflation has returned to above 3%. On June 11, the European Central Bank raised interest rates for the first time in three years, increasing the deposit rate to 2.25%. The Bank of England followed suit with hints of similar action, and markets are betting that the Bank of Japan will raise rates to 1.25% on September 18.

The inflation line is rising, and another line is quietly thickening: the supply of IOUs.

The total U.S. national debt has surpassed $40 trillion, amounting to $120,000 per American. Among G7 nations, only Germany has a debt-to-GDP ratio below 100%. Corporations are also rushing to borrow: global corporate bond issuance is projected to reach $4.9 trillion in 2026, setting a new record—nearly $20 billion borrowed each business day; just five AI giants have issued $220 billion in bonds solely for building data centers.

With abundant supply and few buyers, and with buyers complaining that the interest rate is too low, the price of IOUs has steadily declined. The fuse has been burning for six months, yet no one has smelled smoke.

In this market cycle, there’s a central figure: Scott Bessent, the U.S. Secretary of the Treasury. The media has dubbed him “America’s Chief Bond Trader,” and he’s embraced the title. His job is to sell the largest pile of IOUs in U.S. history.

On August 19, he acted: the cap on Treasury repurchase agreements doubled from $2 billion to $4 billion. The government bought back some of its own IOUs. The Treasury directly intervened to support the price of its own debt.

Here’s a number worth pausing to consider: $4 billion, in the context of America’s $40 trillion debt, is a seventh decimal place. Yet the market has interpreted this tiny amount as a signal that the Treasury is trying to “manipulate yields.” When the government steps in to suppress interest rates, the next step is effectively printing money—this is a “depreciation trade.” High yields aren’t a sign of strong economic fundamentals; they reflect rising debt and inflation. That’s when you buy hard assets.

Gold rose about 10% in August, Bitcoin surged to nearly $80,000, and mining stocks climbed 33% in one month. The market has named this buying surge the "Bessent Bid."

But Bassent couldn't hold down yields. After he stepped in, the 10-year Treasury yield still approached 4.75%—he failed to suppress it, only triggering a Bitcoin rally.

Then, the fire in Jackson Hole turned it all back again.

On August 28, Fed Chair Walsh spoke at Jackson Hole, cutting straight to the point: "Inflation is not slowing." He pledged to fight until reaching the 2% target.

The weight of this statement can only be understood in context. Prior to this, the market’s baseline expectation had been “hold steady, possibly even cut rates,” and global interest rate pricing was built on this assumption. When the world’s most important central bank suddenly reverses course—even if only in words—all assets must be repriced. After the speech, the probability of a September rate hike surged from a remote possibility to about two-thirds, then neared 70%.

The second match fell: the Middle East conflict escalated again, oil prices rose further, and inflation concerns were reinforced once more.

Logic loop completed: Oil price shock → inflation rebound → central banks shift from观望 to rate hikes → debt instruments demand higher interest rates →叠加 unprecedented supply → prices collapse. Six months of slow burn, two weeks of explosive ignition.

The immediate manifestation of the surge was a series of psychological barriers being broken within the same week. Why are "round-number levels" important? Because the bond market operates on reference points. Numbers like 3% and 5% hold no inherent magic, but they have served as long-standing psychological anchors for the entire market. Once these anchors are broken, stop-loss orders, algorithmic trades, and passive funds all activate simultaneously, creating a self-reinforcing selling pressure that continues until the next anchor emerges.

It wasn't that the fundamentals changed within a week—it was a year's worth of accumulated momentum that converged in a single week, breaking through all reference points.

The question now is: The central bank is raising interest rates—what happens to debt?

Central banks raise interest rates not to rescue debt—rate hikes target inflation alone. Debt is a fiscal matter, and central bank governors repeatedly emphasize this, their tone growing more weary each time.

But the contradiction is real, and it has a specific name: fiscal dominance. When governments borrow too much, they push central banks to avoid raising rates. If the central bank tolerates inflation to help the government save on interest costs, markets will immediately conclude, "This central bank is captive to fiscal policy," and demand higher inflation compensation—causing long-term rates to rise even faster. The United States in the 1970s serves as a textbook example: a decade of central bank hesitation led to double-digit inflation and double-digit interest rates.

So the central bank’s logic is counterintuitive: by raising short-term rates to dampen inflation expectations, we create the possibility of lowering long-term rates. Debt issues can only be resolved through fiscal tightening or growth—neither of which is in the central bank’s toolkit.

What you're buying in the market isn't yield—it's whether you still trust the central bank.

The most striking fact right now is the lack of coordination: the central bank is tightening, while the government is borrowing more. This divergence is clearly visible in the yield curve—the 30-year Treasury is falling much more sharply than the 2-year. What does duration mean? Simply put, the longer the maturity of a bond, the more sensitive its price is to interest rate changes. And the 30-year bond is precisely the IOU most sensitive to fiscal policy.

When both sides aren't cooperating, the money will leave first.

In the week before Wash's speech, the fund flows were very clear:

Outflows were from U.S. assets. U.S. equities saw $22.3 billion in weekly outflows, the third-largest this year; money market funds saw $19.7 billion in outflows; high-yield bonds and energy funds are also experiencing withdrawals.

Inflows were directed toward three areas: European equities (+$7.9 billion), Asia (+$4.8 billion), and emerging markets, marking seven consecutive weeks of inflows amid outflows from the U.S.; short-duration bonds (+$6.3 billion), a seven-week high, with investors favoring short over long; and gold funds (+$4.2 billion), a six-month high, driven by safe-haven demand. Note that the inflows into gold funds occurred prior to Walsh’s remarks, reflecting the lingering effect of the previous narrative.

Data for the week following Wash’s remarks has not yet been released. However, from price movements, gold and emerging market bonds are declining while the dollar is rising, indicating capital is flowing back into cash and short-term dollar-denominated assets. Last week’s “diversification” may now be overshadowed by a “dollar rebound.” Next week’s data will confirm this. By then, the current sell-off may already have shifted to a new set of drivers.

In the same cycle of rising yields, gold rises when "fiscal pressure suppresses rates" but falls when "the central bank genuinely hikes rates." By early September, gold had declined to around $4,360, roughly 20% below its peak of $5,420 on January 28.

The IOUs are still growing thicker. Those writing IOUs are borrowing, those lending are choosing, the central bank is raising interest rates, and the treasury is increasing its spending.

As for who will ultimately pay the bill, the chief bond trader said, "It's not a serious situation"; the Federal Reserve Chair said, "Inflation is not slowing down." The market said nothing. It was just counting.