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.

Actually I’m not even mad at AOL and Time Warners. That’s amazing
The landscape of mergers and acquisitions is littered with business flops, some catastrophic, highly visible disasters that were often hugely hyped before their eventual doom. […]