Using daily abnormal currency returns for the universe of countries with flexible exchange rates, we show local currency depreciations ahead of unscheduled, public sovereign debt downgrade announcements. Consistent with the private information hypothesis, the effect is stronger in lower institutional quality countries and holds after we control for concurrent public information and for publicly available rumors about the forthcoming downgrades. Our results persist when abnormal currency returns are adjusted for global carry and dollar risk factors, world equity and bond returns, as well as local stock market returns. Finally, the currency depreciations are permanent, providing evidence for a link between fundamentals and currency markets.

Rating agencies consult with local government officials several days prior to official announcements of sovereign debt rating changes, making information leakage likely. Using cross-country data from 1988 to 2012, we find evidence of information leakage. In particular, we find statistically and economically significant negative daily abnormal stock index returns prior to downgrade announcements. These effects are more pronounced in countries with lower institutional quality, and they persist during times with no downgrade rumors and no concurrent bad news in general. A mild post-announcement reversal consistent with overreaction to pre-event downgrade rumors highlights the adverse effects of such leakage and, thus, should be a policy concern for capital market regulators.