Beset by a selloff in Treasuries that’s sent benchmark yields to multidecade highs, the US government is finding itself increasingly dependent on investors who only buy if the price is right.

The evolution in who forms the world’s biggest bond market is underway after it swelled seven-fold to $32 trillion over the past two decades, powered by Uncle Sam’s rampant borrowing.

Relatively less important than they once were are the foreign governments, central banks and pension funds that display a less knee-jerk sensibility toward prices and hoover up traditionally risk-free securities — which pay predictable returns and are issued in dollars. Although some are flirting with winnowing their holdings, they are typically holding Treasuries for the long-run. Call them slow money.

The footprint of private investors, meanwhile, is expanding. They own about 70% of federal debt, near the most since 1990. And almost a 10th of the Treasury market belongs to hedge funds, who have other assets to pick from and whose use of leverage to exploit market dislocations has drawn the eyes of regulators concerned over risks to financial stability. In the hunt for returns, it doesn’t take much for such investors to turn away. They’re the fast money.

For the likes of US Treasury Secretary Scott Bessent and Federal Reserve Chairman Kevin Warsh, the worry is that price-sensitive buyers now wield more power than ever if they suddenly take fright at monetary policy, the economic trajectory, widening US deficits or any presidential proclamation.

Yes, the US government is still finding creditors to bankroll its spending, but those investors are less reliable — and their fickleness is contributing to a rise in yields.

To Anshul Pradhan, head of US rates strategy at Barclays Plc, it’s a behavior that reveals the true cost of money for the US.

“The investor base has become more discerning,” he said. “A market with large price-insensitive buyers can absorb supply with relatively little adjustment. A market that relies on private capital may require a larger concession.”In the context of this year’s bond selloff, the transformation is taking on even bigger significance. While driven largely by global factors such as a surge in oil prices as well as an improved economic growth outlook, the repricing has revived concerns over the US government’s fiscal policy. It’s also pushing up the cost of borrowing for companies and individuals.

An Australian state-run fund last year said it was reducing its Treasury holdings on concern over US President Donald Trump’s tariff and tax plans. And this September, Norges Bank Investment Management, a unit of Norway’s central bank, proposed reducing its sovereign debt holdings, saying it could see better risk-adjusted returns from other fixed-income assets.

Companies, meanwhile, have been selling record amounts of debt to finance developments in artificial intelligence and the infrastructure to support it, a bet that’s helped drive a frenzy in the stock market.

Unlike foreign central banks, who typically buy Treasuries to help manage national reserves and exchange rates, private investors have a greater ability to dump Treasuries in favor of corporate debt or stocks. The Fed, meanwhile, is no longer snapping up bonds as part of a quantitative-easing program designed to boost the economy.

“As investors, central bankers are less volatile, in part because they are more restricted in what they can buy,” said Paul Donovan, chief economist at UBS Global Wealth Management. “The fickle, less-captive private sector has increased its bond-market influence.”The retreat of central banks, often considered among the least price-sensitive buyers, has made way for depository institutions, hedge funds and other investors that are relatively more price-sensitive.

Bloomberg Economics estimated that the decline in Fed and foreign official holdings of Treasuries at one point added roughly 105 basis points worth of term premium — or the extra payout that investors demand in return for the risks of owning 10-year Treasuries instead of just rolling over short-dated securities for the same amount of time.

Another key source of demand for long-dated bonds may be fading now that managers of company pension funds have more than enough money on hand to pay their retirees, and are often shut off to new members.

Corporate pensions collectively had around 114% of the funding they needed as of September, according to the Milliman 100 Pension Funding Index. These accounts were just 82% funded in July 2020. As they notched winnings in the stock market, they had incentive to limit their risks by moving into bonds whose projected income can be closely matched to their future liabilities to retirees.

Jason Williams, a rates strategist at Citigroup Inc., said that waning pension-fund demand may push the Treasury to cut sales of long-dated debt in favor of greater short-dated bill issuance.

“The trend in corporate defined-benefit pensions has been to freeze or close,” said Stephen Douglass, chief economist at NISA Investment Advisors. “As a result, you stop accumulating new liabilities in the distant future.”A rise in hedge funds’ Treasury holdings was flagged by Fed researchers as the funds quadrupled their position between 2012 and 2025, to constitute almost a fifth of their assets. Their absorption of US government debt has outpaced other US creditors, leaving the funds with roughly 8.5% — or about $2.7 trillion — of outstanding Treasuries as of late last year.

It’s a noteworthy sum given hedge funds’ ability to move rapidly, leverage their trades and their flexibility in selling a Treasury security.

A share of hedge-fund trades take advantage of the relative value in gaps between comparable rates in the market. Prominent examples include the basis trade, which targets the spread between futures and bonds, and swap spreads, which wagers between interest-rate swaps and Treasuries. Macro hedge funds also make bets on the direction of yields.

“Leveraged buyers boost demand and keep yields from rising too far,” said Steven Blitz, a managing director at TS Lombard, citing their activity in swap spreads and the basis trade. But “any sharp up move in repo rates and these positions are undone, creating a flood of US Treasuries.”To illustrate the potential threat of hedge funds’ holdings, market participants, regulators and the Fed have pointed to March 2020, when investors sought to sell bonds for cash ahead of pandemic lockdowns.

The selloff challenged hedge funds’ basis-trade positions, which exacerbated the market moves. But the trade has been shrinking in recent months, an indication that the leveraged strategy isn’t a cause for concern.

Still, the trade underscores the split between fast-money strategies and those of major central banks like the Fed — especially as price-sensitive investors make up an increasing portion of the market.

“Global bond markets are adjusting to a less forgiving buyer base,” wrote a TS Lombard team led by Alexandros Xenofontos. “Governments will still fund themselves, but increasingly at prices set by more discretionary investors.”