Despite widespread media interest in bull and bear markets, academic research that seeks to formally define bull markets is almost non-existent. This paper defines bull and bear markets in relation to a simple model of mean return regimes, and implements the definition using two formal turning...

The market for unseasoned equity has the unusual and distinguishing feature of periods of concentrated activity in terms of both volume and underpricing. This paper formally documents the existence of such periods using a regime-switching model that dates transitions between hot and cold states....