The Globe and Mail reports in its Tuesday edition that a U.S. sovereign downgrade by Moody's has exacerbated investor worries about a looming debt time-bomb that could spur bond market vigilantes who want to see more fiscal restraint from Washington. A Reuters dispatch says the ratings agency cut America's pristine sovereign credit rating by one notch on Friday, the last of the major ratings agencies to downgrade the country, citing concerns about the nation's growing $36-trillion (U.S.) debt pile. U.S. President Donald Trump's sweeping tax-cut bill, which had been stalled for days by Republican infighting over spending cuts, won approval from a key congressional committee on Sunday in a rare victory for Mr. Trump and House Speaker Mike Johnson. Uncertainty over the final shape of the bill has weighed on markets. "The bond market has been keeping a sharp eye on what transpires in Washington this year in particular," said Carol Schleif, chief market strategist at BMO Private Wealth, who said that Moody's downgrade may make investors more cautious. "As Congress debates the 'big, beautiful bill' the bond vigilantes will be keeping a sharp eye on making them toe a fiscally responsible line," Ms. Schleif said.