Markets Head Lower in Wake of Concerns About U.S. Debt

The United States’ loss of its last triple-A credit rating and mounting concerns about government debt are threatening to disrupt the relative calm in financial markets that has prevailed since President Trump began pausing tariffs early last month.

One factor jarring markets is a bill in Congress that would make Mr. Trump’s signature 2017 tax cuts permanent and could add trillions of dollars to federal debt. A House committee voted to approve the bill on Sunday night although it was expected to remain a focus of contentious congressional debate.

On Friday, the ratings firm Moody’s cited the legislation, along with broader concerns about the fiscal deficit and growing debt costs, when it downgraded the credit rating of the United States. The move by Moody’s means that all three major rating agencies no longer consider the United States qualified for their top credit ratings.