Global Bond Market Selloff: Are We at Another Turning Point?

Written by Xiaobing, Deep Tide TechFlow

During trading on May 19, the yield on the 30-year U.S. Treasury bond surged to 5.177%, its highest level since August 2007.

The last time the coupon on a newly issued 30-year Treasury bond reached 5% was also in August 2007. Two months later, two hedge funds under Bear Stearns collapsed, kicking off the subprime mortgage crisis. This isn't to say history will necessarily rhyme, but when the world's largest, deepest, and so-called "risk-free" asset market pushes yields back to levels seen on the eve of a financial tsunami, you'd better understand exactly what's happening.

What's more alarming is that this time, it's not just the United States.

It's Not Just the US; It's a Global Sell-off

If it were only U.S. Treasury yields rising, the story would be simpler – markets anticipating inflation and expecting the Fed to hike rates, nothing more.

But what happened over the past week is on a completely different magnitude.

From May 15 to 18, long-term government bond yields in major developed countries experienced a rare "coordinated surge":

Japan's 30-year government bond yield broke through 4%, hitting an all-time high since the instrument was first issued in 1999; the UK's 30-year gilt yield surged to its highest level since March 1998; Germany's 10-year bond yield touched its highest point since May 2011.

If you overlay these charts, you see a chilling picture: Bond traders in Tokyo, London, Frankfurt, and New York, across four time zones, all made the same decision in the same week: sell.

According to Bloomberg, this was the worst week for U.S. Treasuries since the Trump tariff shock in April 2025, with the 30-year yield approaching its cyclical peak from 2023.

Bond traders are among the most conservative people on the planet. When they start selling in sync, the market senses not just panic, but something structural beginning to loosen.

What Caused the Global Bond Market Sell-off?

Laying all the clues on the table, three main themes are intertwined:

The first line is oil.

Since the US-Iran war broke out at the end of February, tensions in the Strait of Hormuz have persisted for nearly three months. April's US CPI hit a three-year high year-over-year, and the PPI recorded its largest increase since early 2022, up 6% year-over-year. This isn't a mild return of inflation; it's a clear second shock.

The logic for bondholders is straightforward: if inflation can't be suppressed over the next five years, locking in a fixed coupon for 30 years means losing purchasing power with each passing year. So they either sell or force the issuer to offer higher coupons as compensation.

This is why this round of selling is concentrated in long-dated bonds – 10-year, 20-year, 30-year. The longer the maturity, the more sensitive to inflation.

The second line is debt.

The U.S. government's fiscal deficit continues to expand, requiring the Treasury to issue more bonds. Auctions for 3-year and 10-year notes saw demand fall short of expectations, indicating that as yields keep rising, investors' capacity to absorb the massive supply of US debt is being tested.

Supply is increasing, but demand is shrinking. Foreign central banks, especially the biggest buyer of US debt over the past two decades, are reducing their holdings. This is a crucial shift: US Treasuries no longer have a natural buyer base.

Japan faces a similar situation. Markets worry the Japanese government may need to introduce an extra budget to cope with economic pressures, worsening deficit expectations. The UK's troubles are more direct, with Prime Minister Starmer's political crisis further shaking market confidence in UK fiscal discipline, pushing the 30-year gilt yield to a 28-year high.

The third line is the central bank's "credibility problem."

This is the most subtle layer.

At its latest meeting, the Federal Reserve held the federal funds rate in the 3.5%-3.75% range. Surprisingly, internal divisions emerged, with three of the twelve voting members publicly objecting to the dovish language in the statement. This hawkish dissent was interpreted by the market as a warning to the incoming new Chair, Kevin Warsh: don't think about cutting rates easily.

Interest rate futures markets have now pushed the probability of a rate hike in December to 44%, whereas at the beginning of the year, the market generally expected at least two rate cuts.

A complete 180-degree reversal in expectations, occurring in less than five months.

What Does 5% Mean?

Many people don't have a strong feeling about "U.S. Treasury yields." What do they really have to do with your life, your assets, or the Bitcoin in your account?

Let's put it this way.

The 30-year Treasury yield can be understood as the "waterline" for global asset pricing. It represents the closest thing to a "risk-free" long-term rate of return on the planet. The fair valuation of all other assets – stocks, real estate, gold, Bitcoin, private equity – is essentially built by adding a risk premium on top of this waterline.

When the waterline rises, everything has to be recalculated.

For example: You hold a tech growth stock that the market was willing to give a 30x P/E ratio because it believed in its future cash flows. But now a 30-year Treasury can give you a 5% "risk-free" return. Over 30 years, the same money in bonds would more than double your principal. Why take the risk of giving an uncertain tech company a 30x valuation?

Thus, valuations need to come down.

The same applies to mortgages. The 30-year fixed mortgage rate in the US essentially follows the 10-year Treasury yield. If the 10-year breaks above 4.6%, new mortgage applicants could face rates above 7%. This is why if long-term Treasury yields continue climbing above 5%, pressure may extend beyond the bond market to real estate, small-cap stocks, high-valuation growth stocks, and any sector reliant on low-cost long-term capital.

As for gold and Bitcoin, their common feature is that they generate no cash flow.

In the zero-interest-rate era, this wasn't a problem because the alternative was a Treasury yielding 0.5%. But now the alternative is a Treasury yielding 5%, and the situation is completely different.

Over the past three weeks, Bitcoin's performance has perfectly illustrated the "macro alternative" dynamic.

During the week when the 10-year Treasury yield broke through 4.5% and the 30-year approached 5.1%, US spot Bitcoin ETFs saw net outflows of approximately $700 million;

Bitcoin’s price fell back below $80,000 from above $82,000. On May 19, the same day the 30-year yield hit 5.18%, Bitcoin, altcoins, and other risk assets came under pressure.

The logic chain is simple:

Institutional investors face a straightforward arithmetic problem. Putting $1 million into a 30-year Treasury yields a steady $50,000 annually for thirty years with principal returned at maturity – nearly zero risk. Putting the same money into Bitcoin means betting it can outperform that 5% compound interest.

The insidious nature of compound interest is that 5% over 30 years multiplies to 4.3 times. That means Bitcoin needs to outperform by 4.3 times over 30 years just to "break even" on the opportunity cost. Sounds easy? But only if you can withstand any drawdown of over 50% along the way.

This is why the logic "every dollar in Bitcoin is a dollar not earning that 5%" creates a rotation of capital that continues to pressure non-yielding assets.

The Real Cause for Concern Is Something Else

Let's return to the 5.18% figure itself.

Many analyses interpret this as "short-term tightening pressure." I disagree.

If you take a broader view, the biggest macro backdrop for global asset prices over the past forty years has been the long-term decline in interest rates. The 10-year US Treasury yield was 15% in 1981 and fell to 0.5% in 2020. For a full 40 years, the waterline was sinking. All the "value investing logic," the "60/40 portfolio," the "tech stock valuation models," and even the narrative of whether Bitcoin could become "digital gold" were built on this long-term trend.

The problem now is that this 40-year downtrend may have ended in 2020.

What we are witnessing is the early stage of the waterline beginning to reverse and rise.

"The market is starting to price in the Fed having to work harder to suppress inflation," said Ed Al-Hussainy, a portfolio manager at Columbia Asset Management. He added that this sell-off reflects not only concerning inflation paths but also an accelerating economy.

If his assessment is correct, then 5.18% is not the end, but the starting point of a new range.

A deeper issue is debt.

U.S. federal debt is already close to $37 trillion. Every 1 percentage point increase in interest rates means the U.S. Treasury must pay hundreds of billions of dollars more in interest annually. When interest expenses surpass the defense budget, surpass healthcare spending, and eventually consume everything, the market will force the government to either drastically cut spending or monetize the debt.

Historically, the endgame of every major debt cycle has been one of these two paths.

U.S. Treasuries are called "ballast" because they serve as the foundational collateral for the global financial system. Bank capital adequacy ratios, insurance company solvency, pension fund duration matching, hedge fund repo financing, central bank foreign exchange reserves – at the bottom of all these chains lies U.S. debt.

When the ballast price fluctuates violently, the whole ship rocks.

In 2023, Silicon Valley Bank collapsed because of unrealized losses on its Treasury holdings. If long-term yields above 5% become the norm, who will be the next to surface with problems?

There is no standard answer to this question. But as an investor, you should at least ask one more question against your asset allocation:

Do the valuation models for my assets still assume zero interest rates?

If so, recalculate.

The waterline has changed.