This study examines the joint evolution of risk-neutral stock index and bond yield volatilities by using the Chicago Board Option Exchange S&P500 volatility index (VIX) and the Bank of America Merrill Lynch Treasury Option Volatility Estimate Index (MOVE). I use bivariate regime-switching models to investigate the alternation of “high-risk” and “low-risk” markets, where the high-risk regime is characterized by higher and more volatilities with weaker cross-market linkages. Common information about economic and financial conditions appears to drive VIX and MOVE fluctuations between the two risk regimes. Two-regime specifications also distinguish between information spillover and common information effects. Ignoring regime shifts leads to spurious extreme persistence and incomplete inferences about asymmetric volatility. The findings carry important implications for asset allocation.

Using monthly stock and bond return data in the past 150 years (1855–2001) for both the US and the UK, this study documents time-varying stock–bond correlation over macroeconomic conditions (the business cycle, the inflation environment and monetary policy stance). There are different patterns of time variation in stock–bond correlations over the business cycle between US and UK, which implies that bonds may be a better hedge against stock market risk and offer more diversification benefits to stock investors in the US than in the UK. Further, there is a general pattern across both the US and the UK during the post-1923 subperiod and during the whole sample period: higher stock–bond correlations tend to follow higher short rates and (to a lesser extent) higher inflation rates.