The stock market opened with losses Monday as trading began for the first time since the U.S. government suffered a significant hit to its creditworthiness.

The Dow Jones Industrial Average, Nasdaq composite and S&P 500 all fell after the opening bell Monday, following a weekend of fading stock futures and spiking bond yields driven by U.S. debt concerns.

The Dow was down 217 points after the opening bell, a decline of 0.6 percent. The S&P and Nasdaq were down 1 percent and 1.3 percent, respectively.

Moody’s Ratings shook markets after the Friday closing bell when it downgraded the federal government’s credit rating from triple-A to double-A. It was the first time the agency has ever changed it assessment of U.S. creditworthiness.

The downgrade reflects an increase “in government debt and interest payment ratios to levels that are significantly higher than similarly rated sovereigns,” the agency said in a Friday release.

The Moody’s downgrade came as House Republicans made progress on a bill that would extend President Trump’s 2017 tax cut law and add a slew of other deductions. The measure is expected to add trillions of dollars to the national debt by a wide range of economic analysts.

The U.S. debt is already north of $36 trillion, and is expected to increase rapidly as higher interest rates make payments even more expensive. While both Democrats and Republicans have accused the other party of driving the U.S. into a debt crisis, neither Trump nor former President Biden took serious steps to reduce the debt during their previous terms.

Developing