The credit rating agency Moody’s has stripped the United States of its triple-A credit rating, warning investors about rising levels of government debt and a widening budget deficit. The agency has shifted the US rating down one notch to AA1, while changing its outlook from negative to stable.

The decision comes after the U.S. deficit for the current fiscal year hit $1.3 trillion last month, despite only being six months into the fiscal year, which began on October 1.