A black swan is an unpredictable event that is beyond what is usually expected of a situation and potentially severe consequences. Black swan events are rate, have a severe impact, and many people often insist they were apparent in hindsight. The last significant black swan in financial markets came with the 2008 global crises.
The term comes from the Western belief that all swans are white. In 1697 the Dutch explorer Willem de Vlamingh discovered black swans in Australia. The discovery was unexpected and profoundly changed zoology.
Everything was rolling along in the markets at