Rare and unexpected occurrences have proven through the history that they should not be taken for granted, especially when it is not possible to estimate the intensity of their effect. N. N. Taleb has defined three features that distinguish one kind of these events from the rest. Those three features are the rarity of the event, the extreme consequences and its retrospective explanation. Events that are characterized by these criteria are called The Black Swans. The Black Swan phenomenon is closely related to behavioral finance, multidisciplinary branch whose concept and biases, among else, explain the irrational behavior in the context of appearance of The Black Swans. There are well known history events like this, such as World War I, 2008 world financial crisis, the sinking of the Titanic, COVID-19 pandemic, etc. Every one of these events has affected the society as well as the financial markets. Behavioral finance also gives us an insight into how The Black Swan can affect investors and markets, but also potential strategies which can be worked on, in order to reduce risk of The Black Swan.