The black swan theory is a metaphor that describes an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight. The theory was developed by Nassim Nicholas Taleb.

What? Fat-Finger-Error?
A Lehman Brothers trader keyed in £300m instead of £3m at the end of business on Monday and the FTSE100 lost 130 points, or a […]