We use an empirical model to categorize firms into portfolios based on operational risk. Using these portfolios, we show that a strategy of buying firms in the highest decile of operational risk and shorting firms in the lowest decile of operational risk earned a positive but insignificant...

We propose a novel intraday instantaneous volatility measure which utilises sequences of drawdowns and drawups non-equidistantly spaced in physical time as indicators of high-frequency activity of financial markets. The sequences are re-expressed in terms of directional-change intrinsic time...

This paper estimates a bivariate HEAVY system including daily and intra-daily volatility equations and its macro-augmented asymmetric power extension. It focuses on economic factors that exacerbate stock market volatility and represent major threats to financial stability. In particular, it...