Here's what the internetz says about the definition
"The black swan theory or theory of black swan events 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."
"Classic black swan events include the rise of the internet and personal computer, the September 11 attacks, and World War I."
"Grey swan is a term used to describe a potentially very significant event whose possible occurrence may be predicted beforehand but whose probability is considered small."
I would think the fall of Afghanistan, 2008 housing crash and the 2020 Presidential election would count.
Waiting for the next shoe to drop?
In a nutshell it used to be something like 5-7 zeros before the 9 probability event. Assumed for planning purposes to be so far outside the norm as to not be worth taking into account, based on data at hand and projections based on same.
Gets goofy and does stuff like dot com bust and 2008 when unknowns are thrown in or parameters change.
Like 5 mile plus asteroid striking is super low probability event, but if you blew up the moon it would rise drastically…🤠
Black swans are very rare. So basically a rare event.
Petey