Yield spreads (corrected for exchange rate risk) over 10-year German securities of European Union (EU) countries that did not join Economic and Monetary Union (EMU) experienced an average decrease of 14.20 basis points during the first 3 years after the beginning of Currency Union. Conversely, Euro-area countries' adjusted spreads registered an average rise of 11.98 basis points in the same period. This article examines the elements (a possible change in the relative importance of domestic or international risk factors) behind these results using both panel estimations in the two groups of countries and a country-by-country specification in each of them.