AP BIOLOGY

Detailed explanation-1: -tail event (plural tail events) (probability) an event associated with a given infinite sequence that is determined by any subsequence of the form (a “tail” of that sequence) a low-probability event quotations ▼ an event that initiates an activity.

Detailed explanation-2: -“Tails” refer to the end portions of distribution curves, the bell-shaped diagrams that show statistical probabilities for a variety of outcomes. In the case of investing, bell curves plot the likelihood of achieving different investment returns over a specified period.

Detailed explanation-3: -9/11 was a tail event. The financial crisis of 2007/08 was a tail event.

Detailed explanation-4: -Tail risk is the unforeseen risk of a three standard deviation move, which has the magnitude to upset and reverse markets. Because of its infrequency it is difficult to predict. Typical tail risk events, like the 9/11 attacks or the Japanese tsunami are classic examples.