GREY SWAN

Extremely unlikely, unforeseen event with a major impact on the valuation of a security or health of the overall market. It is different from a black swan event in which the total impact is difficult to predict. Amid the possibility of identifying the properties and possible impact of such events, it is hard to create exact computations about the total impact. The term was coined by Lebanese American essayist, scholar, and statistician Nassim Nicholas Taleb.