U.S. Treasury buybacks may provide temporary relief in the bond market but leave the underlying debt burden intact, JPMorgan co-head of global fundamental research James Sullivan said. The Treasury Department, led by Secretary Scott Bessent, said Wednesday it would at least double government debt buybacks from Sept. 9 through Nov. 4 while issuing shorter-dated bills in place of longer-duration bonds. Sullivan compared the strategy with refinancing long-term obligations through shorter-term borrowing. He warned that roughly $40 trillion in U.S. government debt, about $76 trillion across developed-market governments, and record corporate issuance could intensify competition for investors. China’s Treasury holdings are at an 18-year low, while foreign-government holdings in U.S. Treasury custody accounts are at their lowest in 14 years. Leading artificial-intelligence companies have issued $200 billion of debt this year, up 80% from a year earlier. Higher bond yields are now above the S&P 500’s earnings yield, making choices between fixed income and equities more difficult.