A model for predicting when markets will sell-off has become somewhat of a holy grail for market practitioners over the years. This topic has gained momentum as a significant body of professionals have been caught out by financial crises – the more recent ones being Asia 1997, Russia 1998, Dotcom Bubble 2000, Global 2008 and 2011. This question of when leads us to the conundrum of ‘Why Markets Sell-off’.