But Moody's Moody's Sovereign Issuers – 10-Year Transition and Default Rates report, which shows real historical trends in government credit downgrades and upgrades, provides a different view. From year-ends 2013 to 2023, Moody's reported four small or medium-sized Aa1-rated sovereigns of 125 in total. None remained Aa1 or were upgraded to Aaa. One dropped a notch, to Aa2, the other three notches, to Aa3. In short, Aa1 rated sovereigns are subject to credit downgrade risk.