After the closing bell on Friday, Moody’s became the last major credit-rating firm to downgrade U.S. sovereign debt from its perfect AAA status to Aa1. The firm argues that the U.S. is on a trajectory to increase entitlement spending—without the necessary government revenues to keep interest payment ratios at levels similar to other sovereign nations.

The Moody's announcement follows similar actions from Fitch and S&P in recent years and could result in higher borrowing costs.

The US has lost its last perfect credit rating, as influential ratings firm Moody's expressed concern over the government's ability to pay back its debt. In lowering the US rating from 'AAA' to 'Aa1', Moody's noted that successive US administrations had failed to reverse ballooning deficits and interest costs.