"There is a serious risk of a bond market crisis that could lead to a wider financial crisis," one economist said of the bill.

The debt of other governments looks newly risky, too, with long-term yields rising across much of the rich world (see chart). Britain’s 30-year borrowing cost has hit 5.5%, its highest since 1998, aside from a spike in April.

In the world’s biggest bond market, investors are pushing back against President Donald Trump’s tax-cut plan. On Wednesday, they drove yields on benchmark 30-year Treasuries to as high as 5.1%, leaving them just shy of a two-decade high and sparking declines in stocks and the dollar,

Republicans brought the president’s tax cuts one step closer to reality, but Wall Street remains on edge about the fiscal costs.

Harvard University's bonds, which are part of the Ivy League school's $8.2 billion debt pile, struggled on Friday amid an increasingly fraught standoff with U.S. President Donald Trump's administration.

Investors worried about the US debt pile are weighing the House vote to approve President Trump's "big, beautiful" tax bill.

Yields on the 30-year bond reached 5.089%, the highest since October 2023, after a lackluster auction for 20-year securities. Yields on the 10-year Treasury note rose to 4.595%, the highest since February.

After the United States lost its last perfect credit rating on Friday, Republicans and Democrats responded by pointing fingers at each other.