What is a black swan?
In short
A black swan is an event outside normal expectations, with enormous consequences, that in hindsight is often presented as if it had been predictable.
How safe is a plan built on the idea that tomorrow everything will work the way it did yesterday? The term, popularized by Nassim Nicholas Taleb, describes events that fall outside what we expect based on past experience. The image comes from the belief that all swans are white: no matter how many white swans you’ve seen, one black swan is enough to overturn the rule.
Think of a business that organizes its deliveries assuming a certain bridge will stay open. If an unprecedented event destroys it, it’s not just one route that changes; the entire operation may grind to a halt. In crypto, an unexpected systemic shock can likewise hit prices, exchanges and access to funds all at once. This is a hypothetical example, not a label for every collapse as a black swan.
Why it matters
Analysis tools and risk models usually rely on historical data and assumptions. A black swan can lie outside those limits. The fact that something hasn’t happened before doesn’t mean it can’t happen. We find this distinction more useful than trying to guess the next big crisis.
In an extreme shock, liquidity, i.e. the ability to trade without a big impact on the price, can dry up abruptly. Leveraged positions, i.e. exposure larger than the initial capital, may be forcibly closed. Even different cryptocurrencies may fall together, limiting the protection you’d expect from diversification.
What to watch out for
Not every big crash is a black swan. A known risk that was ignored or underestimated doesn’t become unpredictable just because it ended up causing damage. Also, what counts as unexpected depends on the observer’s knowledge and perspective. The term doesn’t necessarily refer to negative events, although in markets it’s mainly used for crises.
The other trap appears after the event: suddenly everyone finds a story that explains it and presents it as inevitable. But an explanation in hindsight doesn’t prove we could have predicted it in time.