Using a rich dataset of high frequency historical information we study the determinants of European sovereign bond returns over calm and crisis periods. We find that the importance of the equity risk factor varies greatly over time and crucially depends on country risk. In low risk
countries, government bond returns are negatively related to equity returns, regardless of market conditions. Investors appear to migrate from low risk government bonds to stocks in calm periods and in the opposite direction when markets are under stress. On the other hand,
government bonds of high risk countries lose their “safe-asset” status and exhibit more equity-like behaviour during the sovereign debt crisis, with positive and strongly significant co-movements relative to the stock market. Interestingly, this segmentation of the government bond market results in higher diversification benefits for fixed income investors and pension funds in periods of sovereign stress.